研究者データベース

清水 裕樹(シミズ ユウキ)
工学研究院 機械・宇宙航空工学部門 人間機械システム
教授

基本情報

所属

  • 工学研究院 機械・宇宙航空工学部門 人間機械システム

職名

  • 教授

学位

  • 博士(工学)(名古屋大学)

ホームページURL

J-Global ID

研究キーワード

  • 超精密制御   超精密加工   超精密計測   

研究分野

  • ものづくり技術(機械・電気電子・化学工学) / 加工学、生産工学
  • ものづくり技術(機械・電気電子・化学工学) / 機械要素、トライボロジー
  • ものづくり技術(機械・電気電子・化学工学) / 設計工学

職歴

  • 2021年10月 - 現在 北海道大学 大学院工学研究院 機械宇宙工学部門 教授
  • 2020年04月 東北大学大学院工学研究科ファインメカニクス専攻 准教授
  • 2016年04月 東北大学大学院工学研究科ファインメカニクス専攻 准教授
  • 2011年02月 東北大学大学院工学研究科 ナノメカニクス専攻 准教授
  • 2002年04月 - 2011年01月 株式会社日立製作所 機械研究所/中央研究所/研究開発本部 研究員(2006~)

学歴

  •         - 2009年01月   名古屋大学   工学研究科   機械理工学専攻
  •         - 2002年03月   東北大学   工学研究科   機械電子工学専攻
  •         - 2000年03月   東北大学   工学部   機械電子工学科

所属学協会

  • 砥粒加工学会   日本トライボロジー学会   精密工学会   日本機械学会   

研究活動情報

論文

  • Wijayanti Dwi Astuti, Kuangyi Li, Ryo Sato, Hiraku Matsukuma, Yuki Shimizu, Wei Gao
    APPLIED SCIENCES-BASEL 12 10 2022年05月 
    An optical angle sensor based on the collimated mode-locked femtosecond laser (Fs) beam, in which the angle measurement is carried out by observing the second harmonic wave generated by irradiating the Fs beam towards MgO:LiNbO3 crystal, is proposed. The angle detection is demonstrated by identifying the second harmonic generation (SHG) spectrum peaks against the angular position of the rotating stage-mounted MgO:LiNbO3 crystal that represents the measurement object. The MgO:LiNbO3 with a length of 2 mm, a cut-off angle of 47 degrees, a diameter of 5 mm, and 5% of MgO:LN, is rotated within the phase-matching angle over a wavelength range from 1480 nm to 1640 nm. Angle measurement is also carried out by placing the crystal at different positions along the laser beam propagation direction to confirm the feasibility of the angle sensor where the measurement range, measurement sensitivity, and resolution of the proposed method are also evaluated. The result shows that the proposed angle sensor can overcome the working distance limitation of conventional angle sensors and has no specific material target requirement. Since the configuration of the proposed angle sensor is not limited by the specification of the measurement target, it is expected to have wide potential applications, especially in the manufacturing process and inspection process.
  • Ryo Sato, Yuki Shimizu, Hiraku Matsukuma, Wei Gao
    APPLIED SCIENCES-BASEL 12 9 2022年05月 
    This paper presents an intentional investigation of the effect of the object tilt angle on the tracking local minimum method (TL method), which is the one for detecting the measurement target position of the object optical axis, in a chromatic confocal probe employing a differential dual-fiber-detector optical system with a mode-locked femtosecond laser as the light source. The effect of the object tilt angle on dual-detector confocal probes, and even chromatic confocal probes, has not been investigated in detail so far, although the effect of object tilt angle on scanning confocal probes has been studied. At first, to examine the influence of the object tilt angle on the TL method, a theoretical model is established, and numerical simulations are performed based on the established theoretical equation. Then, the effect of aberrations in confocal optics on the confocal response curve is investigated in experiments. Finally, investigations on the effect of the object tilt angle on the TL method are demonstrated in experiments.
  • Yifan Hong, Ryo Sato, Yuki Shimizu, Hiraku Matsukuma, Wei Gao
    SENSORS 22 8 2022年04月 
    This paper proposes a new optical configuration for a two-axis surface encoder that can measure the in-plane (X-axis) and out-of-plane (Z-axis) displacements of a positioning stage. The two-axis surface encoder is composed of a scale grating and a sensor head. A transparent grating is employed in the sensor head for measurement of the Z-directional displacement of the scale grating based on the Fizeau-type measurement method; a reference beam reflected from the transparent grating and the zeroth-order diffracted beam from the scale grating are superimposed to generate an interference signal. A pair of prisms and a beam splitter are also employed in the sensor head, so that the positive and negative first-order diffracted beams can be superimposed over a long working distance to generate an interference signal for measurement of the X-directional displacement of the scale grating. Focusing on the new, extended Z-directional measurement mechanism, proof-of-principle experiments were carried out to verify the feasibility of the proposed optical configuration for the surface encoder that can measure the uni-directional displacements of a scale grating along the X- and Z-axis. Experimental results from the developed optical configuration demonstrated the achievement of a Z-directional measuring range of +/- 1.5 mm.
  • Hiraku Matsukuma, Kaede Matayoshi, Masashi Nagaoka, Yuki Shimizu, Wei Gao
    Measurement: Sensors 18 2021年12月 
    It is known that linear motion errors for linear guides can be measured by the autocollimation method. In this case, it is necessary to install a mirror on the measurement target. On the other hand, if a light with a wavelength sufficiently longer than that of the surface roughness of the measurement target is used, the need for a mirror is eliminated. We have proposed an autocollimation method using a mid-infrared laser. In the original prototype of mid-infrared autocollimator, the angle of laser irradiation is 45° to the measurement target. However, this method does not allow us to obtain a long measurement range. Therefore, we construct a system in which the laser irradiation angle is set to 0° by controlling the polarization of light. By using this method, autocollimation is applied to a sample with a root mean square roughness Rq of 0.2 μm, and an angular resolution of 1.1 arc-second is obtained.
  • Yuki Shimizu, Lue Quan, Dong Wook Shin, Hiraku Matsukuma, Wei Gao
    Measurement: Sensors 18 2021年12月 
    An optical setup for measurement of the pitch deviation of a diffraction grating has been designed and developed. Multiple autocollimation units are employed in the setup so that the angles of diffraction of diffracted beams can be detected simultaneously. This enables the optical sensor head to evaluate the scale pitch deviation while separating the contributions from the scale local slope and the scale angular error motion that cannot be achieved by the conventional laser diffraction methods. In this paper, firstly, the resolution needed for the angle sensor is estimated using a theoretical analysis. After that, the design of an optical head for the angle sensor is carried out. A built prototype optical head is also used to conduct some feasibility tests, and the measurement of the pitch deviation of a scale grating brought from a commercial optical linear encoder is demonstrated.
  • Kai Zhang, Yuki Shimizu, Hiraku Matsukuma, Yindi Cai, Wei Gao
    INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 117 9-10 2883 - 2893 2021年12月 
    This paper presents the application of the edge reversal method for a further accurate evaluation of the three-dimensional tool geometry of a single-point diamond tool with an atomic force microscope (AFM). In the edge reversal method, the tip radius of an AFM probe, which ranges from a few nm to several-ten nm, can be evaluated quantitatively by using measured AFM profile data of a tool cutting edge and an indentation mark generated by the tool cutting edge. The AFM tip radius obtained by the edge reversal method is utilized in this paper to reconstruct the three-dimensional profile of the cutting edge of a single-point diamond tool from the AFM data, which is obtained in measurement as the convolution of the tool edge profile and the shape of AFM tool tip. The validity of the obtained AFM tip radius in the edge reversal method is verified by employing it for the compensation of the AFM image of a two-dimensional (2D) grating artifact. Finally, the reconstruction of the three-dimensional profile of the cutting edge of a single-point diamond tool is carried out, and the cutting edge radius and the nose radius of the tool are evaluated quantitatively based on the reconstructed three-dimensional (3D) profile of the cutting tool.
  • Xin Xiong, Yuki Shimizu, Hiraku Matsukuma, Wei Gao
    Sensors 21 21 7412 - 7412 2021年11月08日 [査読有り][通常論文]
     
    An interferometric self-calibration method for the evaluation of the pitch deviation of scale grating has been extended to evaluate the pitch deviation of the long-range type linear scale by utilizing the stitching interferometry technique. Following the previous work, in which the interferometric self-calibration method was proposed to assess the pitch deviation of the scale grating by combing the first-order diffracted beams from the grating, a stitching calibration method is proposed to enlarge the measurement range. Theoretical analysis is performed to realize the X-directional pitch deviation calibration of the long-range linear scale while reducing the second-order accumulation effect by canceling the influence of the reference flat error in the sub-apertures’ measurements. In this paper, the stitching interferometry theory is briefly reviewed, and theoretical equations of the X-directional pitch deviation stitching are derived for evaluation of the pitch deviation of the long-range linear scale. Followed by the simulation verification, some experiments with a linear scale of 105 mm length from a commercial interferential scanning-type optical encoder are conducted to verify the feasibility of the self-calibration stitching method for the calibration of the X-directional pitch deviation of the linear scale over its whole area.
  • Bo Wen, Sho Sekine, Shinichi Osawa, Yuki Shimizu, Hiraku Matsukuma, Andreas Archenti, Wei Gao
    Machines 9 11 271 - 271 2021年11月06日 [査読有り][通常論文]
     
    This paper describes a comparison of the mechanical structures (a double-sided beam and a cantilever beam) of a probe in a tool edge profiler for the measurement of a micro-cutting tool. The tool edge profiler consists of a positioning unit having a pair of one-axis DC servo motor stages and a probe unit having a laser displacement sensor and a probe composed of a stylus and a mechanical beam; on-machine measurement of a tool cutting edge can be conducted with a low contact force through measuring the deformation of the probe by the laser displacement sensor while monitoring the tool position. Meanwhile, the mechanical structure of the probe could affect the performance of measurement of the edge profile of a precision cutting tool. In this paper, the measurement principle of the tool edge profile is firstly introduced; after that, slopes and a top-flat of a cutting tool sample are measured by using a cantilever-type probe and a double-sided beam-type probe, respectively. The measurement performances of the two probes are compared through experiments and theoretical measurement uncertainty analysis.
  • Yuki Shimizu, Qiaolin Li, Masami Kogure, Kimitaka Nishimura, Yuki Sato, Hiraku Matsukuma, Wei Gao
    Measurement Science and Technology 32 10 2021年10月 [査読有り][通常論文]
     
    A system for on-machine diameter measurement of a ceramic cylindrical workpiece on a precision grinding machine is developed by employing a commercial optical micrometer, which can measure the diameter of a workpiece in various sizes. One of the drawbacks of the optical micrometer is its poor thermal stability, which could affect the on-machine diameter measurement in a machine shop where the room temperature is not controlled well. To address the issue, in this paper, a comparative measurement method with a calibrated reference artefact having identical material and nominal diameter with respect to a ceramic workpiece is newly proposed. In the proposed comparative method, the workpiece diameter is evaluated through detecting its deviation from that of the reference artefact calibrated by using a high-precision measuring instrument such as a coordinate measuring machine in advance of the on-machine measurement. Meanwhile, in the comparative measurement method, the uncertainty of the reference artefact should also be taken into consideration as a source of uncertainty. In this paper, measurement uncertainty analysis is carried out for the proposed comparative method based on GUM, while verifying the uncertainty of the reference artefact diameter through numerical calculations by a Monte Carlo method.
  • Dong Wook Shin, Lue Quan, Yuki Shimizu, Hiraku Matsukuma, Yindi Cai, Eberhard Manske, Wei Gao
    Applied Sciences 11 17 8028 - 8028 2021年08月30日 [査読有り][通常論文]
     
    Major modifications are made to the setup and signal processing of the method of in-situ measurement of the pitch of a diffraction grating based on the angles of diffraction of the diffracted optical frequency comb laser emanated from the grating. In the method, the improvement of the uncertainty of in-situ pitch measurement can be expected since every mode in the diffracted optical frequency comb laser can be utilized. Instead of employing a Fabry-Pérot etalon for the separation of the neighboring modes in the group of the diffracted laser beams, the weight-of-mass method is introduced in the method to detect the light wavelength in the Littrow configuration. An attempt is also made to reduce the influence of the non-uniform spectrum of the optical comb laser employed in the setup through normalization operation. In addition, an optical alignment technique with the employment of a retroreflector is introduced for the precise alignment of optical components in the setup. Furthermore, a mathematical model of the pitch measurement by the proposed method is established, and theoretical analysis on the uncertainty of pitch measurement is carried out based on the guide to the expression of uncertainty in measurement (GUM).
  • Xin Xiong, Lue Quan, Yuki Shimizu, Hiraku Matsukuma, Wei Gao
    Measurement Science and Technology 32 6 2021年06月 [査読有り][通常論文]
     
    The principle of the self-calibration method for the evaluation of a planar scale grating having a constant pitch is extended to realize the evaluation of the pitch distribution of a planar scale grating having variable line spacings (VLSs) along the X-and Y-directions. In the conventional self-calibration method, the wavefronts in the zeroth-order diffracted beam and the first-order diffracted beams observed by a Fizeau interferometer arranged in the Littrow configuration were employed to evaluate the pitch deviation of a scale grating. The arithmetic operation with the wavefront data realizes the evaluation of the pitch deviation over a large area in a short time, while cancelling the influence of the out-of-flatness of a scale grating. Meanwhile, theoretical equations in the conventional self-calibration method cannot be directly applied to the evaluation of a VLS grating due to its unique properties of the pitch distribution. In this paper, major modifications are thus made to the conventional theoretical equations for deriving the pitch distribution of a VLS grating. To verify the performance of the newly proposed method, the pitch distribution of a VLS grating employed in a commercial planar absolute encoder is evaluated in experiments.
  • Qiaolin Li, Yuki Shimizu, Toshiki Saito, Hiraku Matsukuma, Yindi Cai, Wei Gao
    Applied Sciences (Switzerland) 11 10 2021年05月02日 [査読有り][通常論文]
     
    Attempts are made in this paper to improve the quality of the stitching between adjacent arc-profiles in the stitching linear-scan method for the roundness measurement of a cylinder in a small dimension. The data in the edge region of an arc-profile, which could be influenced by the pressure angle of the measurement probe of a linear-scan stylus profiler, are eliminated in the stitching process to improve the quality of stitching. The effectiveness of the elimination of the edge region of an arc-profile is evaluated by employing the cross-correlation coefficient of two adjacent arc-profiles as an evaluation index. Furthermore, a modification is made to the experimental setup to reduce the misalignment of a workpiece along its axial direction with respect to the scanning probe. Experiments are carried out by using the modified setup to demonstrate the feasibility of the stitching linear-scan method for the roundness measurement of a small cylinder, which is difficult to measure by the conventional rotary-scan method.
  • Yuki Shimizu, Xu Ma, Hiraku Matsukuma, Wei Gao
    Measurement Science and Technology 32 5 2021年05月 [査読有り][通常論文]
     
    A new technique for measurement of the apex angle of a right-angle prism is proposed. A reference artefact is newly employed as the datum for angle measurement, and the apex angle of a target prism is measured by detecting its deviation from that of the reference artefact by using a pair of optical angle sensors. At first, the principle of the apex angle measurement with the reference artefact and the optical angle sensors are addressed. After that, an optical angle sensor capable of evaluating various sizes of right-angle prisms over a large measurement range is designed and developed. A two-dimensional position-sensitive detector is employed as the photodetector for the optical angle sensor so that a high resolution and a wide measurement range can be achieved simultaneously. To avoid the influence of the interference between a directly-reflected beam and an internally-reflected beam when measuring a face of a right-angle prism, the optical setup is designed to have a laser beam that is made incident to a measurement surface with an oblique incidence. After the design and development of the optical angle sensor, the measurement system has been developed and some basic experiments are carried out to evaluate the basic performance of the developed optical angle sensor. The feasibility of the proposed technique of the prism apex angle measurement is also demonstrated through experiments and theoretical measurement uncertainty analysis based on GUM.
  • Yuki Shimizu, Liang Chia Chen, Dae Wook Kim, Xiuguo Chen, Xinghui Li, Hiraku Matsukuma
    Measurement Science and Technology 32 4 2021年04月 [査読有り][通常論文]
     
    Optical metrology is one of the key technologies in today's manufacturing industry. In this article, we provide an insight into optical measurement technologies for precision positioning and quality assessment in today's manufacturing industry. First, some optical measurement technologies for precision positioning are explained, mainly focusing on those with a multi-axis positioning system composed of linear slides, often employed in machine tools or measuring instruments. Some optical measurement technologies for the quality assessment of products are then reviewed, focusing on technologies for form measurement of products with a large metric structure, from a telescope mirror to a nanometric structure such as a semiconductor electrode. Furthermore, we also review the state-of-the-art optical technique that has attracted attention in recent years, optical coherence tomography for the non-destructive inspection of the internal structures of a fabricated component, as well as super-resolution techniques for improving the lateral resolution of optical imaging beyond the diffraction limit of light. This review article provides insights into current and future technologies for optical measurement in the manufacturing industry, which are expected to become even more important to meet the industry's continuing requirements for high-precision and high-efficiency machining.
  • Hiraku Matsukuma, Keisuke Adachi, Takuma Sugawara, Yuki Shimizu, Wei Gao, Eiji Niwa, Yoshihiro Sasaki
    Nanomanufacturing and Metrology 4 1 53 - 66 2021年03月 [査読有り][通常論文]
     
    This paper presents a compact XYZ micro-stage driven by an impact driving mechanism. A moving body is translationally actuated along the X-, Y-, and Z-axes in millimeter-scale range and with nanometer-scale resolution. Cr–N thin-film strain sensors are integrated into the micro-stage for closed-loop positioning. Closed-loop control is also carried out. The motion errors in six degrees of freedom are also investigated for this micro-stage. It is clarified by analysis of finite element method that rotational motion errors around the driving axis are caused by torques due to tensions from the elastic hinges of micro-stage. The mechanical structure of XYZ micro-stage to cancel out the torque generated is proposed and the second prototype is fabricated. Although the rotational motion error is successfully suppressed in the second prototype, a rotational motion error of more than 0.1° remains due to remaining torque and assembly error of the elastic hinges. Then, in order to reduce the rotational motion error, the prototype is designed in which the location of elastic hinges is single-layered. By designing a mechanical structure in which torque is suppressed, all rotational motion errors are successfully reduced to less than 0.05° in the prototype with single-layer hinges.
  • Yuki Shimizu, Yasuhiro Mizutani, Masaki Michihata
    Nanomanufacturing and Metrology 4 1 67 - 68 2021年03月 [査読無し][通常論文]
  • Yuki Shimizu
    Nanomanufacturing and Metrology 4 1 3 - 27 2021年03月 [査読有り][通常論文]
     
    Laser interference lithography is an attractive method for the fabrication of a large-area two-dimensional planar scale grating, which can be employed as a scale for multi-axis optical encoders or a diffractive optical element in many types of optical sensors. Especially, optical configurations such as Lloyd’s mirror interferometer based on the division of wavefront method can generate interference fringe fields for the patterning of grating pattern structures at a single exposure in a stable manner. For the fabrication of a two-dimensional scale grating to be used in a planar/surface encoder, an orthogonal two-axis Lloyd’s mirror interferometer, which has been realized through innovation to Lloyd’s mirror interferometer, has been developed. In addition, the concept of the patterning of the two-dimensional orthogonal pattern structure at a single exposure has been extended to the non-orthogonal two-axis Lloyd’s mirror interferometer. Furthermore, the optical setup for the non-orthogonal two-axis Lloyd’s mirror interferometer has been optimized for the fabrication of a large-area scale grating. In this review article, principles of generating interference fringe fields for the fabrication of a scale grating based on the interference lithography are reviewed, while focusing on the fabrication of a two-dimensional scale grating for planar/surface encoders. Verification of the pitch of the fabricated pattern structures, whose accuracy strongly affects the performance of planar/surface encoders, is also an important task to be addressed. In this paper, major methods for the evaluation of a grating pitch are also reviewed.
  • Wijayanti Dwi Astuti, Hiraku Matsukuma, Masaru Nakao, Kuangyi Li, Yuki Shimizu, Wei Gao
    Sensors (Switzerland) 21 2 1 - 14 2021年01月02日 [査読有り][通常論文]
     
    This paper proposes a new optical angle measurement method in the optical frequency domain based on second harmonic generation with a mode-locked femtosecond laser source by making use of the unique characteristic of the high peak power and wide spectral range of the femtosecond laser pulses. To get a wide measurable range of angle measurement, a theoretical calculation for several nonlinear optical crystals is performed. As a result, LiNbO3 crystal is employed in the proposed method. In the experiment, the validity of the use of a parabolic mirror is also demonstrated, where the chromatic aberration of the focusing beam caused the localization of second harmonic generation in our previous research. Moreover, an experimental demonstration is also carried out for the proposed angle measurement method. The measurable range of 10,000 arc-seconds is achieved.
  • Hiraku Matsukuma, Ryo Sato, Yuki Shimizu, Wei Gao
    International Journal of Automation Technology 15 4 529 - 536 2021年 [査読有り][通常論文]
     
    Confocal probes have been widely adopted in vari-ous industries owing to their depth-sectioning effects. A dual-detector differential chromatic confocal probe using a mode-locked femtosecond laser source is proposed herein, and the measurement range expansion of the probe using a supercontinuum light source is discussed. Supercontinuum light has an extremely wide spectrum. A simulation based on wave optics is performed to evaluate the detection sensitivity and measurable range by considering the chromatic aberration of the lens materials. Additionally, an experimental setup is constructed using a supercontinuum light source, and its feasibility is validated. A measurable range of 200 μm is adopted in the experi-ment, and three-dimensional surface profile measurements are performed. However, the developed confo-cal probe has not been used for surface topography measurements. Experiments are conducted to verify the performance of the developed probe.
  • Yuki Shimizu, Yuri Kanda, Xu Ma, Kakeru Ikeda, Hiraku Matsukuma, Yasunari Nagaike, Masaki Hojo, Keita Tomita, Wei Gao
    Precision Engineering 67 339 - 349 2021年01月 [査読有り][通常論文]
     
    A major modification has been made to the conventional mode-locked femtosecond laser autocollimator so that the apex angle of a small prism, which is a transparent object difficult to be measured by the conventional optical methods, can be measured. In the oblique-incidence optical setup, a collimated mode-locked femtosecond laser is at first made incident to a target prism, and the laser beam reflected from the prism surface is then projected onto a reflective-type grating for angle measurement based on the principle of the femtosecond laser autocollimator. With the robust signal processing technique in the femtosecond laser autocollimator where the spectrum of the first-order diffracted beams emanated from the grating is captured by the fiber detector, high-precision angle measurement can be realized even on a surface having a small area for measurement and/or on a surface having low reflectivity. An oblique-incidence femtosecond laser autocollimator with a fiber-based femtosecond laser source is developed, and its basic characteristics are then evaluated in experiments. An experimental setup composed of the oblique-incidence femtosecond laser autocollimator and a high-precision rotary table is also constructed for prism angle measurement. To avoid the influence of the internally reflected beam in a prism, a method employing the characteristic of Brewster's angle is newly proposed, and its feasibility is verified through experiments. The uncertainty analysis on the measurement of the prism apex angle by the oblique-incidence mode-locked femtosecond laser is also carried out based on GUM.
  • Yuki Shimizu, Ryo Ishizuka, Kazuki Mano, Yuri Kanda, Hiraku Matsukuma, Wei Gao
    Precision Engineering 67 36 - 47 2021年01月 [査読有り][通常論文]
     
    An absolute surface encoder for measurement of absolute in-plane position with a mode-locked femtosecond laser and a planar scale grating having variable periods along the two orthogonal directions is proposed. In the proposed method, the absolute in-plane position is measured through observing the spectra of the coupled groups of the positive and negative first-order diffracted mode-locked femtosecond laser emanated from a single point on the planar scale grating. Due to the dispersive effect of the planar scale grating having variable periods, each of the diffracted modes has a unique angle of diffraction associated with the absolute position information. Therefore, the absolute in-plane position can be detected by obtaining the peak frequencies in the optical spectra of the coupled positive and negative first-order diffracted beams received by dual detector units. The dual-detector configuration of the optical head also contributes to improving the robustness of the absolute position measurement against the angular error motion of the planar scale grating. Furthermore, interference signals capable of being used for the improvement of the absolute position measurement can be generated under the dual detector configuration. Results of the numerical calculations for the theoretical verification of the proposed method, fabrication of a scale grating having a variable period (VLS grating) with interference lithography, design and development of the optical head, as well as the results of basic experiments by using the developed optical head and the VLS grating, are reported.
  • Lue Quan, Yuki Shimizu, Xin Xiong, Hiraku Matsukuma, Wei Gao
    Precision Engineering 67 1 - 13 2021年01月 [査読有り][通常論文]
     
    A new method for measurement of the pitch deviation of a scale grating by an optical angle sensor based on the laser autocollimation is proposed. In the proposed method, the scale pitch deviation is evaluated through detecting the change in the angles of diffraction of the first-order diffracted beams, which is associated with the change in the scale pitch deviation. The optical angle sensor unit is designed to measure the angles of diffraction of both the positive and negative first-order diffracted beams simultaneously so that the influences of the scale form error and the roll error motion of the linear slide for the scanning of a linear scale can be canceled through the differential operation. The optical angle sensor unit based on the laser autocollimation is newly designed and developed, and the pitch deviation of a linear scale from a commercial interferential scanning-type linear encoder is evaluated by the developed setup to verify the feasibility of the proposed method in experiments. The scale form error obtained through the differential operation is also compared with the one evaluated by a commercial Fizeau interferometer. Furthermore, the uncertainty analysis on the proposed pitch deviation measurement is carried out based on GUM to theoretically verify the feasibility of the proposed method.
  • Hiraku Matsukuma, Yun Asumi, Masashi Nagaoka, Yuki Shimizu, Wei Gao
    Precision Engineering 67 89 - 99 2021年01月 [査読有り][通常論文]
     
    In this study, we proposed an autocollimator for the angular measurement of rough surfaces. A mid-infrared laser having a wavelength of 2.8 μm was employed as the light source because it possesses high specular reflectivity on rough surfaces. Although a conventional autocollimator using a visible laser has a high resolution of angular measurement, it can only be used to measure mirror surfaces because the intensity distribution of the reflected light from a rough surface changes significantly due to the influence of diffused reflection. The suitability of a mid-infrared laser in an autocollimator for the angular measurement of rough surfaces (sub-micrometer level) was verified through simulations using reflection models. Therefore, a continuous-wave mode fluoride glass fiber based mid-infrared laser was developed for the autocollimator. Furthermore, an autocollimation unit was designed and constructed for detecting the angular displacement of mid-infrared laser light reflected from a target surface. The capability of the developed autocollimator for the angular measurement of rough surfaces was demonstrated through experiments.
  • Hiraku Matsukuma, Bo Wen, Shinichi Osawa, Sho Sekine, Yuki Shimizu, Wei Gao
    Nanomanufacturing and Metrology 3 4 282 - 291 2020年12月 [査読有り][通常論文]
     
    A new on-machine profiler employing a cantilever beam was proposed and developed to measure the sharp micro-cutting edges of precision cutting tools with low measuring force of 0.1 mN. The proposed profiler consists of a probe unit and a positioning unit. The probe unit employs a stylus mounted on the free end of a hollow triangular cantilever beam and a laser displacement sensor to detect the deflection of the cantilever beam. The positioning unit consists of two single-axis DC servo motor stages for precise positioning of the probe unit. The cantilever is designed with the assistance of the finite element method. In order to demonstrate the feasibility of the proposed measurement system, experiments are conducted and the measurement result for a micro-cutting edge is compared with that by a commercial profiler. Furthermore, a method to compensate for the measurement error caused by the lateral displacement of the cantilever beam is proposed. The compensated measurement results show good agreement within ± 2 μm with those obtained by the commercial profiler.
  • Chong Chen, Yuki Shimizu, Ryo Sato, Hiraku Matsukuma, Wei Gao
    Applied Sciences (Switzerland) 10 20 1 - 15 2020年10月02日 [査読有り][通常論文]
     
    This paper presents an off-axis differential method for the improvement of a femtosecond laser differential chromatic confocal probe having a dual-detector configuration. In the proposed off-axis differential method employing a pair of single-mode fiber detectors, a major modification is made to the conventional differential setup in such a way that the fiber detector in the reference detector is located at the focal plane of a collecting lens but with a certain amount of off-axis detector shift, while the fiber detector in the measurement detector is located on the rear focal plane without the off-axis detector shift; this setup is different from the conventional one where the difference between the two confocal detectors is provided by giving a defocus to one of the fiber detectors. The newly proposed off-axis differential method enables the differential chromatic confocal setup to obtain the normalized chromatic confocal output with a better signal-to-noise ratio and approaches a Z-directional measurement range of approximately 46 µm, as well as a measurement resolution of 20 nm, while simplifying the optical alignments in the differential chromatic confocal setup, as well as the signal processing through eliminating the complicated arithmetic operations in the determination of the peak wavelength. Numerical calculations based on a theoretical equation and experiments are carried out to verify the feasibility of the proposed off-axis differential method for the differential chromatic confocal probe with a mode-locked femtosecond laser source.
  • Bo Wen, Yuki Shimizu, Yu Watanabe, Hiraku Matsukuma, Wei Gao
    Precision Engineering 65 230 - 239 2020年09月 [査読有り][通常論文]
     
    A new contact-type on-machine measurement system is designed and developed for the evaluation of a micro cutting edge profile. The measurement system is composed of a compact probe unit having a sharp stylus mounted on a flexible beam, an inner displacement sensor for the detection of the stylus displacement, and a two-axis precision positioning system. For the evaluation of tool faces having a steep slope, a new probing procedure with the enhancement of the inner displacement sensor integrated into the probe unit is newly proposed. After the design and development of the probe unit, the feasibilities of the developed measurement system and the proposed probing procedure are demonstrated through some basic experiments. Regarding the out-of-straightness and angular error motion of the two-axis positioning system employed in the developed measurement system, a pair of length gauges is newly employed to reduce the influences of error motions of the stage system. The topographic profile of the micro cutting edge obtained by the measurement system with the modified probe unit is then compared with those obtained by a commercial stylus profiler and a laser confocal microscope. The feasibility and effectiveness of the developed on-machine tool edge profile measurement system are also demonstrated through uncertainty analysis based on the GUM with the Monte-Carlo method.
  • Ryo Sato, Chong Chen, Hiraku Matsukuma, Yuki Shimizu, Wei Gao
    Measurement Science and Technology 31 9 2020年09月 [査読有り][通常論文]
     
    This paper presents an improved data processing method, which is referred to as the tracking intersection method, for a fibre-based dual-detector differential chromatic confocal probe with a mode-locked femtosecond laser source. In the dual-detector differential confocal system, two fibre detectors of an optical spectrum analyzer are employed to detect the spectra of the confocal signals. One of the fibre detectors, referred to as the measurement detector, is located at the confocal position of the confocal system, and the other fibre detector, referred to as the reference detector, is located at a position with a certain offset from the confocal position. In the tracking intersection method, the Z-directional displacement of a measurement object is derived from tracking the wavelength at the intersection point of the two fibre detector outputs. A new algorithm is proposed to generate a normalized output with a sharp peak at the intersection wavelength, from which the intersection wavelength can be detected with a high-sensitivity while the influence of the non-smooth spectral distribution of the femtosecond laser source can be removed. Compared with the previous tracking local minimum method, the new tracking intersection method is more robust to noises in the fibre detector outputs and consequently can realize better performance such as higher resolution and larger range in measurement of the displacement of the object. The advantages of the new method are demonstrated by simulation and experiment.
  • Xin Xiong, Hiraku Matsukuma, Yuki Shimizu, Wei Gao
    Measurement Science and Technology 31 9 2020年09月 [査読有り][通常論文]
     
    A self-calibration method, in which the wavefronts of zeroth and first-order diffracted beams from a scale grating measured by a Fizeau interferometer are employed, is applied for the evaluation of the pitch deviation of a reflective-type linear scale with a grating pitch of 2.048 μm used in a commercial interferential scanning-type optical linear encoder. One of the advantages of the self-calibration method is that the pitch deviation of a scale grating can be evaluated while measuring the out-of-flatness of the scale grating under inspection and the Z-directional out-of-flatness (surface profile) of the reference optical flat in the Fizeau interferometer. Meanwhile, in a practical case, the self-calibration method is valid under the condition where the out-of-flatness of the scale grating is on the same order or less than that of the reference optical flat in the Fizeau interferometer. In this paper, theoretical analysis and numerical calculations are thus carried out to investigate the influence of the out-of-flatness of the scale grating on measurement of the pitch deviation and the out-of-flatness of the reference optical flat. Some experiments with a linear scale from a commercial interferential scanning-type linear encoder are also carried out to verify the feasibility of the self-calibration method for the evaluation of the pitch deviation of the scale having an out-of-flatness of approximately 600 nm over the analyzed area.
  • Kai Zhang, Yindi Cai, Yuki Shimizu, Hiraku Matsukuma, Wei Gao
    Applied Sciences (Switzerland) 10 14 2020年07月 [査読有り][通常論文]
     
    This paper presents a measurement method for high-precision cutting edge radius of single point diamond tools using an atomic force microscope (AFM) and a reverse cutting edge artifact based on the edge reversal method. Reverse cutting edge artifact is fabricated by indenting a diamond tool into a soft metal workpiece with the bisector of the included angle between the tool's rake face and clearance face perpendicular to the workpiece surface on a newly designed nanoindentation system. An AFM is applied to measure the topographies of the actual and the reverse diamond tool cutting edges. With the proposed edge reversal method, a cutting edge radius can be accurately evaluated based on two AFM topographies, from which the convolution effect of the AFM tip can be reduced. The accuracy of the measurement of cutting edge radius is significantly influenced by the geometric accuracy of reverse cutting edge artifact in the proposed measurement method. In the nanoindentation system, the system operation is optimized for achieving high-precision control of the indentation depth of reverse cutting edFigurege artifact. The influence of elastic recovery and the AFM cantilever tip radius on the accuracy of cutting edge radius measurement are investigated. Diamond tools with different nose radii are also measured. The reliability and capability of the proposed measurement method for cutting edge radius and the designed nanoindentation system are demonstrated through a series of experiments.
  • Qiaolin Li, Yuki Shimizu, Toshiki Saito, Hiraku Matsukuma, Wei Gao
    Applied Sciences (Switzerland) 10 14 2020年07月 [査読有り][通常論文]
     
    Influences of angular misalignments of a small cylinder on its roundness measurement by the method referred to as the stitching linear scan method are theoretically investigated. To compensate for the influences, a technique for measuring angular misalignments of a small cylinder by utilizing the linear-scan surface form stylus profilometer, which is employed for roundness measurement, is newly proposed. In addition, for roundness measurement, a holder unit capable of compensating for the angular misalignments of a small cylinder is developed, and the feasibility of the proposed technique is verified in experiments. Furthermore, a measurement uncertainty analysis of the stitching linear-scan method is carried out through numerical calculations based on a Monte Carlo method.
  • Bo Wen, Yuki Shimizu, Hiraku Matsukuma, Keisuke Tohyama, Haruki Kurita, Yuan-Liu Chen, Wei Gao
    Measurement Science and Technology 31 7 074014 - 074014 2020年07月01日 [査読有り][通常論文]
     
    This paper presents a new strategy for applying a piezoelectric (PZT) force sensor to the measurement of static force in a force sensor-integrated fast tool servo (FS-FTS) system for single-point diamond cutting on planar brittle material substrates. A conventional PZT force sensor unit composed of a PZT force sensor and a charge amplifier cannot be employed for measurement of static force due to the discharging characteristics of PZT materials. In this paper, to realize the long-term stable measurement of static cutting force, the time constant of the PZT force sensor unit is set to be infinitely large by removing the feedback resistor from the charge amplifier. The influence of bias current leakage, which arises as a result of removing the feedback resistor, is compensated through obtaining the differential output of the two PZT force sensor units having identical charge amplifiers and identical thermal characteristics. After microgroove-cutting experiments to verify the stability of the PZT force sensor unit in the conventional FS-FTS unit, a theoretical model for the PZT force sensor unit is established. Some basic experiments are then carried out to verify the feasibility of the proposed differential measurement strategy. Furthermore, a modified FS-FTS unit with a pair of PZT force sensor units based on the proposed strategy is developed, and its effectiveness is demonstrated through experiments.
  • Yuki Shimizu, Hiraku Matsukuma, Wei Gao
    Applied Sciences (Switzerland) 10 11 2020年06月01日 [査読有り][通常論文]
     
    A mode-locked femtosecond laser, which is often referred to as the optical frequency comb, has increasing applications in various industrial fields, including production engineering, in the last two decades. Many efforts have been made so far to apply the mode-locked femtosecond laser to the absolute distance measurement. In recent years, a mode-locked femtosecond laser has increasing application in angle measurement, where the unique characteristics of the mode-locked femtosecond laser such as the stable optical frequencies, equally-spaced modes in frequency domain, and the ultra-short pulse trains with a high peak power are utilized to achieve precision and stable angle measurement. In this review article, some of the optical angle sensor techniques based on the mode-locked femtosecond laser are introduced. First, the angle scale comb, which can be generated by combining the dispersive characteristic of a scale grating and the discretized modes in a mode-locked femtosecond laser, is introduced. Some of the mode-locked femtosecond laser autocollimators, which have been realized by combining the concept of the angle scale comb with the laser autocollimation, are also explained. Angle measurement techniques based on the absolute distance measurements, lateral chromatic aberration, and second harmonic generation (SHG) are also introduced.
  • Yuki Shimizu, Shota Takazono, Yuri Kanda, Hiraku Matsukuma, Wei Gao, Hajime Inaba
    JSME 2020 Conference on Leading Edge Manufacturing/Materials and Processing, LEMP 2020 2020年 
    Angle sensors based on the laser autocollimation are often employed to evaluate surface profiles of a target of interest. The authors have developed a femtosecond laser angle sensor, in which a spectrometer or an optical spectrum analyzer with a single-mode fiber is employed as the photodetector for simultaneous capturing of the multiple optical modes. In this paper, the concept of the femtosecond laser angle sensor is applied to evaluate the surface profile of a target of interest. An optical setup is designed in such a way that each mode in the spectrum of the mode-locked femtosecond is utilized as the laser beam to measure the local slope of a measurement target at each different point to evaluate the surface profile. Some basic experiments are carried out by using the developed optical setup with a mode-locked femtosecond laser source to evaluate basic performances of the developed optical setup as an optical angle sensor.
  • Hiraku Matsukuma, Masanori Matsunaga, Kai Zhang, Yuki Shimizu, Wei Gao
    International Journal of Automation Technology 14 4 546 - 551 2020年 [査読有り]
     
    This paper presents a fabrication method of a two-dimensional (2D) diffraction grating with isolated photoresist pattern structures in order to reduce fluc-tuation in the grating pitch due to the thermal expan-sion. At first, theoretical calculations for the fabrication of a 2D diffraction grating with isolated pho-toresist pattern structures are carried out to estimate the influences of exposure and development time on the pattern structures to be fabricated through the pattern exposure and development process. A diode laser-based compact non-orthogonal two-axis Lloyd’s mirror interferometer system designed in a size of 500 mm × 840 mm is then built on a breadboard for stable mask-less interference lithography. Basic per-formances of the newly developed compact interfer-ometer system are evaluated through the fabrication of 2D diffraction gratings to demonstrate the feasibil-ity of the theoretical calculations and the developed lithography system.
  • Yuki Shimizu, Wei Gao, Hiraku Matsukuma, Károly Szipka, Andreas Archenti
    CIRP Annals 69 1 469 - 472 2020年 [査読有り][通常論文]
     
    The included angle of a V-groove on a large ceramic workpiece with a length of 500 mm is measured on an ultra-precision surface grinding machine. A pair of electronic dial gauges is mounted on the grinding wheel head to detect the ground flank surfaces of the groove. A calibrated artefact with identical material and nominal geometry but a shorter length of 100 mm is aligned side-by-side with the workpiece. The influences of machine scanning motion errors and thermal errors on the angle measurement are compensated through measuring the angular deviations of the V-grooves on the workpiece and on the artefact.
  • Ryo Sato, Yuki Shimizu, Hiraku Matsukuma, Wei Gao
    JSME 2020 Conference on Leading Edge Manufacturing/Materials and Processing, LEMP 2020 2020年 
    Confocal probes are widely employed in many industrial fields due to the depth-sectioning effect. The author’s group has also proposed a chromatic confocal probe employing a mode-locked femtosecond laser source which can realize an axial resolution of 30 nm and a measurement range of 40 µm. Efforts have also been made to improve the thermal stability of the developed femtosecond laser chromatic confocal probe so that the probe can be applied for long-term displacement measurement or surface profile measurement. Meanwhile, surface profile measurement has not been carried out by using the developed femtosecond laser chromatic confocal probe. For the verification of the performance of developed probe in profile measurement, in this paper, an experimental setup is built and a basic experiment is carried out. By using the probe with further improved thermal stability, the measurement of a sample surface profile is carried out. In this paper, the development of the experimental setup with the femtosecond laser chromatic confocal probe, as well as the results of the surface profile measurements, is presented.
  • Hiraku Matsukuma, Shuhei Madokoro, Wijayanti Dwi Astuti, Yuki Shimizu, Wei Gao
    Nanomanufacturing and Metrology 2 4 187 - 198 2019年12月01日 [査読有り][通常論文]
     
    This paper proposes a new optical angle measurement method based on second harmonic generation with a mode-locked femtosecond laser source by taking use of the unique characteristic of high peak power and high-intensity electric field of the femtosecond laser pulses. The angle is measured from the second harmonic wave intensity, which is a function of the angle between the laser beam axis and the optic axis of a nonlinear crystal attached to the target of interest. It is found that the beta barium borate (BBO) crystal is suitable as the nonlinear crystal for this purpose through theoretical simulation. As the first step of research, an experimental demonstration is also carried out in such a way that a change of the second harmonic wave intensity due to the angular displacement of BBO crystal is measured to verify the feasibility of the proposed principle of the angle measurement method.
  • Yuki Shimizu, Kazuki Mano, Hiroki Murakami, Shunsuke Hirota, Hiraku Matsukuma, Wei Gao
    Precision Engineering 60 280 - 290 2019年11月 [査読有り][通常論文]
     
    An optimized beam expansion assembly is newly designed for a non-orthogonal two-axis Lloyd's mirror interferometer to fabricate large-area two-dimensional (2D) diffraction scale gratings in a small-scale manufacturing facility or a research laboratory. Theoretical calculations are at first carried out to quantitatively estimate the influences of the coherence length and the Gaussian light intensity distribution of a collimated laser beam, which is projected onto a mirror-substrate assembly for the generation of interference fringe fields on a substrate. Design optimization of the interferometer is then carried out in such a way that a beam shaper, which contributes to obtain a flat-top light intensity distribution in the collimated laser beam and is expected to reduce the amplitude deviation of the developed pattern structures as well as the pattern exposure time, is integrated into the beam expansion assembly. The feasibility of the newly developed beam expansion assembly is demonstrated through fabricating a 100 mm × 100 mm 2D scale grating having pattern structures with uniform amplitude of approximately 500 nm and a short period of 1 μm.
  • Ryo Sato, Yuki Shimizu, Chong Chen, Hiraku Matsukuma, Wei Gao
    Applied Sciences (Switzerland) 9 19 2019年10月01日 [査読有り][通常論文]
     
    An intentional investigation on the thermal stability of a mode-locked femtosecond laser chromatic confocal probe, which is a critical issue for the probe to be applied for long-term displacement measurement or surface profile measurement requiring long-time scanning, is carried out. At first, the thermal instability of the first prototype measurement setup is evaluated in experiments where the existence of a considerably large thermal instability is confirmed. Then the possible reasons for the thermal instability of the measurement setup are analyzed quantitatively, such as the thermal instability of the refractive index of the confocal lens and the thermal expansion of mechanical jigs employed in the probe. It is verified that most of the thermal instability of the measurement setup is caused by the thermal expansion of mechanical jigs in the probe. For the improvement of the thermal stability of the probe, it is necessary to employ a low thermal expansion material for the mechanical jigs in the measurement setup and to shorten the optical path length of the laser beam. Based on the analysis result, a second prototype probe is newly designed and constructed. The improved thermal stability of the second prototype probe is verified through theoretical calculations and experiments.
  • Keisuke Adachi, Hiraku Matsukuma, Takuma Sugawara, Yuki Shimizu, Wei Gao, Eiji Niwa, Yoshihiro Sasaki
    Nanomanufacturing and Metrology 2 3 131 - 139 2019年09月01日 [査読有り][通常論文]
     
    In this paper, an attempt is made to integrate a compact strain gauge-type displacement sensor referred to as the Cr–N thin-film displacement sensor into the XY micro-stage designed in a small size of 25 mm (X) × 25 mm (Y) × 6.5 mm (Z) to achieve closed-loop nano-positioning of the stage. In the XY micro-stage, which has been developed in the previous study by the authors, Cr–N strain gauges for the Cr–N thin-film displacement sensors are directly fabricated on elastic hinges integrated into the stage structure so that the elastic hinges can be employed as sensors for stage positioning as well as guides for a stage table. In this paper, two types of the Cr–N thin-film displacement sensor having different layouts of the strain gauges, line patterns and land patterns are designed and fabricated. Computer simulation based on the finite element method is also carried out to evaluate the robustness of sensors against the external disturbances from electrical wires soldered onto a sensor surface. After some basic experiments, each of the developed Cr–N thin-film displacement sensors is integrated into the XY micro-stage, and its feasibility is evaluated in experiments.
  • Yuki Shimizu, Kazuki Mano, Kai Zhang, Hiraku Matsukuma, Wei Gao
    Optical Engineering 58 9 92611  2019年09月01日 [査読有り][通常論文]
     
    An optical setup for the nonorthogonal two-axis Lloyd's mirror interferometer, which is composed of a nonorthogonal type of mirror-substrate assembly and a newly designed beam expansion assembly, is proposed to fabricate highly precise two-dimensional (2-D) diffraction scale gratings having uniform pattern structures over a wide area. The beam expansion assembly is designed in such a way that a thin collimated laser beam is at first generated by a small collimating lens to carry out a precise polarization modulation control of subdivided wavefronts in the beam, followed by the generation of a collimated laser beam with the expansion of the thin collimated laser beam by using a beam expander. Since a pair of high-precision half-wavelength plates made of crystalline quartz can be employed in the newly designed optical setup, a much better polarization modulation control can be expected, compared to the conventional optical setup in which low-precision large-size half-wavelength plates made of polycarbonate should have been employed. To verify the effectiveness of the proposed optical setup, theoretical calculations and some basic experiments are carried out by using a prototype optical setup to demonstrate the feasibility of the proposed optical setup for fabrication of highly precise 2-D scale gratings.
  • Yuki Shimizu, Ayaka Ishida, Yuki Matsuno, Hiraku Matsukuma, Wei Gao
    Nanomanufacturing and Metrology 2 2 100 - 110 2019年06月01日 [査読有り][通常論文]
     
    A new concept of reading head for a linear encoder, in which graduations on a scale grating are read by using a micro thermal sensor composed of a thin film resistor, is proposed to realize a compact encoder system. In the proposed reading head, measurement of the in-plane relative displacement between the micro thermal sensor and the scale grating will be carried out in such a way that the graduations on a scale grating are read by the micro thermal sensor through the change in the heat flow between the sensor and the scale grating surface. In this paper, as the first step of research, theoretical calculations based on the theory of heat flow between the sensor and scale interface are carried out. In addition, basic experiments are carried out to search for the possibility of realizing the proposed concept of the reading head based on the micro thermal sensor.
  • Hiraku Matsukuma, Ryo Ishizuka, Masaya Furuta, Xinghui Li, Yuki Shimizu, Wei Gao
    Nanomanufacturing and Metrology 2 2 111 - 123 2019年06月01日 [査読有り][通常論文]
     
    This paper presents the reduction in cross-talk errors in the angular outputs existing in the previously designed six-degree-of-freedom (DOF) surface encoder for nanopositioning and nanometrology. The six-DOF surface encoder is composed of a planar scale grating and an optical sensor head with a reference grating, a displacement assembly and an angle assembly. The diffracted beams from both the scale and the reference gratings are received by the displacement assembly for measurement of the primary XYZ translational motions. The angle assembly only receives the diffracted beams from the scale grating for measurement of the secondary θ θ θ angular motions. In this paper, at first, the cross-talk errors in the angular measurement results of the previous surface encoder are identified to be caused by the diffracted beams from the reference grating leaking into the angle assembly due to the imperfection of the polarization components of the sensor head. An improved design of the sensor head is then carried out to reduce the cross-talk errors by changing the position of the angle assembly in the sensor head. The sensor head is further optimized by replacing the beam splitter located in front of the angle assembly from a cube type to a plate type. Experimental results have demonstrated that the cross-talk errors were reduced from 3.2 arc-seconds to 0.02 arc-second. X Y Z
  • Chong Chen, Ryo Sato, Yuki Shimizu, Taku Nakamura, Hiraku Matsukuma, Wei Gao
    Applied Sciences (Switzerland) 9 3 454  2019年01月29日 [査読有り][通常論文]
     
    A method is proposed to expand the Z-directional measurement range of a fiber-based dual-detector chromatic confocal probe with a mode-locked femtosecond laser source. In the dual-detector chromatic confocal probe, the Z-directional displacement of a measurement target is derived from the peak wavelength in the normalized intensity ratio from the two light intensities obtained by the two identical fiber detectors. I this paper, a new method utilizing the main-lobe and side-lobes of axial responses acquired from both the normalized intensity ratio I and the invert normalized intensity ratio In, which is the inverse of I , is proposed to obtain the seamless relationship between the peak wavelength and the Z-directional displacement of a measurement target. Theoretical calculations and experimental investigation are carried out to demonstrate the feasibility of the proposed measurement range expansion method. n a a
  • Chong Chen, Hiraku Matsukuma, Ryo Sato, Xiuguo Chen, Yuki Shimizu, Wei Gao
    Proceedings of the 2018 IEEE International Conference on Advanced Manufacturing, ICAM 2018 362 - 364 2019年01月16日 [査読有り][通常論文]
     
    In this paper, by moving and adjusting the collecting lens suitably, the main-lobe is moved to the position where gap between main-lobe and side-lobe is located, aimed at solving the problem of discontinuous measurement range. So that the side-lobe of the axial response can be utilized for the purpose of extending the measurement range of the established chromatic confocal probe. Theoretical analysis and numerical simulation are carried out for computing the measurement range of the chromatic confocal probe.
  • Yuri Kanda, Hiraku Matsukuma, Shaoqing Yang, Yuki Shimizu, Hajime Inaba, Wei Gao
    Proceedings of the 2018 IEEE International Conference on Advanced Manufacturing, ICAM 2018 18 - 19 2019年01月16日 [査読有り][通常論文]
     
    This paper presents the development of a frequency comb using a mode-locked fiber laser as the light source for precision dimensional metrology. The mode-locked laser generates an optical pulse train with a central wavelength of approximately 1560 nm. The pulse train was amplified with an erbium-doped fiber amplifier, and its spectrum was broadened to the wavelength range from 1000 nm to 2000 nm. Furthermore, the carrier envelope offset beats were successfully detected by using a common-path f-2 f interferometer.
  • Masami Kogure, Hiraku Matsukuma, Ryo Kobayashi, Yuki Shimizu, Wei Gao
    Proceedings of the 2018 IEEE International Conference on Advanced Manufacturing, ICAM 2018 30 - 31 2019年01月16日 [査読有り][通常論文]
     
    This paper presents measurement of a precision ceramic part having V-shaped surfaces to be measured. Machining of a ceramic part is attracting attentions due to the superior characteristics such as a low thermal expansion coefficient or a high stiffness when being employed in fabrication equipments. Meanwhile, due to the difficulty of machining ceramic part, in general, it is necessary to carry out compensation machining with off-machine measurement. In this paper, aiming to establish a method to evaluate the uncertainty of measurement of an angle between two surfaces in a ceramic part, computer simulation based on the Monte-Carlo method is carried out, while employing data obtained from the measurement carried out by using a commercially available coordinate measuring machine (CMM).
  • Xin Xiong, Hiraku Matsukuma, Xiuguo Chen, Yuki Shimizu, Wei Gao
    Proceedings of the 2018 IEEE International Conference on Advanced Manufacturing, ICAM 2018 220 - 222 2019年01月16日 [査読有り][通常論文]
     
    In this paper, a Fizeau interferometer is used to evaluate the out-of-flatness error and the pitch deviation of a reflective-type linear scale. The out-of-flatness error of the linear scale is evaluated by analyzing the zeroth-order diffracted beam and the positive and negative first-order diffracted beams are measured to evaluate the pitch deviation of the linear scale. Basic stitching technique is also studied and simulated to connect the phase map obtained by the sub-apertures.
  • Lue Quan, Hiraku Matsukuma, Xiuguo Chen, Yuki Shimizu, Wei Gao
    Proceedings of the 2018 IEEE International Conference on Advanced Manufacturing, ICAM 2018 47 - 48 2019年01月16日 [査読有り][通常論文]
     
    A new method using an ultra-sensitive angle sensor to evaluate the grating pitch deviation is proposed in this paper. The principle and theoretical calculation are done to confirm the theoretical feasibility of the new proposed method. Theoretically, with a high resolution optical angle sensor, this method can reach an extremely high resolution of picometers for the evaluation of grating pitch deviation. Compensation methods of angle error during scanning process are also discussed.
  • Masanori Matsunaga, Kazuki Mano, Hiraku Matsukuma, Yuki Shimizu, Wei Gao
    Proceedings of the 2018 IEEE International Conference on Advanced Manufacturing, ICAM 2018 28 - 29 2019年01月16日 [査読有り][通常論文]
     
    A non-orthogonal two-axis Lloyd's mirror interferometer for fabrication of a two-axis diffraction grating designed in a compact size is developed. A design study of the modified optical setup for the interferometer and the results of basic experiments with the developed optical setup are carried out to verify the possibility of fabricating the two-axis fine diffraction grating with a single exposure by the developed interferometer unit.
  • Kazuki Nakamura, Hiraku Matsukuma, Yuki Shimizu, Wei Gao
    Proceedings of the 2018 IEEE International Conference on Advanced Manufacturing, ICAM 2018 26 - 27 2019年01月16日 [査読有り][通常論文]
     
    The laser autocollimation utilizes the function of a lens to convert the angle change of a plane mirror into the displacement of a reflected laser beam focused spot on a photodetector. However, in this method, it is hard to achieve both a high resolution and a wide range measurement simultaneously. In this paper, a new optical angle sensor utilizing a broadband optical frequency comb generated from a femto-second laser source and a diffraction grating is proposed for solving this tradeoff.
  • Ryo Ishizuka, Hiraku Matsukuma, Yuki Shimizu, Wei Gao
    Proceedings of the 2018 IEEE International Conference on Advanced Manufacturing, ICAM 2018 36 - 39 2019年01月16日 [査読有り][通常論文]
     
    In this paper, the analysis of crosstalk error in an optical sensor head for a six degree-of-freedom (DOF) surface encoder is carried out. Since the crosstalk errors among the outputs from the sensor degrade the measurement uncertainty of the surface encoder, a further detailed analysis is required. In this paper, an intensive investigation on the crosstalk errors is carried out throughout some experiments.
  • Yun Asumi, Hiraku Matsukuma, Yuki Shimizu, Wei Gao
    Proceedings of the 2018 IEEE International Conference on Advanced Manufacturing, ICAM 2018 32 - 35 2019年01月16日 [査読有り][通常論文]
     
    This paper presents a development of a mid-infrared laser expected to be used as sensor light source for precision engineering measurement. A ring oscillator based on nonlinear polarization rotation with erbium-doped-fluoride fiber was developed. Laser oscillation at the wavelength of 2.8 μm was obtained with pumping the fluoride fiber by a diode laser at the wavelength of 976 nm. A spectrometer was also developed for real-time measurement of spectra of the laser oscillation. As a result of observing a spectrum, only continuous wave oscillation was gained.
  • Yuki Shimizu, Ayaka Ishida, Hiraku Matsukuma, Wei Gao
    Proceedings of the 2018 IEEE International Conference on Advanced Manufacturing, ICAM 2018 24 - 25 2019年01月16日 [査読有り][通常論文]
     
    This paper presents a numerical analysis of heat flow in a linear encoder system, in which a micro thermal sensor is employed to read line pattern structures on a scale grating. A simple heat transfer model of the interface between the micro thermal sensor and a scale grating is established, and the heat flow at the sensor-grating interface is estimated for the cases of employing scale gratings having line pattern structures with a sinusoidal profile and a triangular profile, respectively, to search for the possibility of employing the output signal from the micro thermal sensor for displacement measurement.
  • Yuki Shimizu, So Ito, Jungchul Lee, Shigeaki Goto, Hiraku Matsukuma, Wei Gao
    Handbook of Manufacturing 541 - 568 2019年01月01日
  • Hiraku Matsukuma, Shuhei Madokoro, Masaru Nakao, Yuki Shimizu, Wei Gao
    Proceedings of SPIE - The International Society for Optical Engineering 11142 2019年 [査読有り][通常論文]
     
    This paper presents an optical angle sensor using characteristics of second harmonic generation (SHG) which is a nonlinear process of electromagnetic field. In a SHG process, the fundamental wave is made incidence into a non-linear optical crystal. The second harmonic wave which has double frequency of the fundamental wave is then generated. The light intensity of the generated second harmonic wave changes with the incident angle of the fundamental wave to the non-linear optical crystal due to phase mismatch which is a factor of determining the conversion efficiency of SHG. The dependence of second harmonic generation on angular displacement is calculated theoretically for mode-locked femto second laser light source. Experiment is also carried out in order to demonstrate the theoretical calculation.
  • Xin Xiong, Yuki Shimizu, Xiuguo Chen, Hiraku Matsukuma, Wei Gao
    Applied Sciences (Switzerland) 8 12 2539  2018年12月07日 [査読有り][通常論文]
     
    Form errors of a planar scale grating, such as pitch deviations and out-of-flatness, are major contributors to the final measurement uncertainty of an interferential scanning-type planar encoder. Following the previous work, in which a method has been proposed to evaluate both the out-of-flatness and the pitch deviations of a planar scale grating by a Fizeau interferometer in Littrow configuration, uncertainty analysis on this method is performed in this paper. Theoretical equations are derived to make quantitative uncertainty analysis while taking possible error factors into account. To overcome the drawbacks of a traditional uncertainty matrix approach, a new procedure is proposed to evaluate the uncertainty in the PV (peak-to-valley) deviation of a surface form, so as to assure the quality of measurement. Experiments are finally conducted to demonstrate the feasibility of proposed uncertainty evaluation method.
  • Yuki Shimizu, Satoshi Kataoka, Wei Gao
    Chinese Journal of Mechanical Engineering (English Edition) 31 1 92  2018年12月01日 [査読有り][通常論文]
     
    This paper proposes a new method for measurement of the roll error motion of a slide table in a precision linear slide. The proposed method utilizes a pair of clinometers in the production process of a precision linear slide, where the roll error motion measurement will be carried out repeatedly to confirm whether the surface form errors of slide guideways in the linear slide are sufficiently corrected by hand scraping process. In the proposed method, one of the clinometers is mounted on the slide table, while the other is placed on a vibration isolation table, on which the precision linear slide is mounted, so that influences of external disturbances can be cancelled. An experimental setup is built on a vibration isolation table, and some experiments are carried out to verify the feasibility of the proposed method.
  • Yuan Liu Chen, Yuki Shimizu, Jun Tamada, Kazuki Nakamura, Hiraku Matsukuma, Xiuguo Chen, Wei Gao
    Precision Engineering 54 284 - 293 2018年10月 [査読有り][通常論文]
     
    Laser autocollimation is innovated for absolute angular position measurement based on an optical frequency comb. The conventional laser autocollimation can only make relative angle measurement due to the unknown angular distance between the incident laser beam and the axis of the autocollimation unit. In the proposed absolute laser autocollimation employed with the femtosecond laser autocollimator, in which a femtosecond laser and a diffraction grating are employed as the measurement light source and the reflector, respectively, a new method is proposed for accurate identification of the angular distance through taking use of first-order diffracted beams from the reflector associated with the optical frequency comb of the femtosecond laser source. With the identified angular distance, the absolute angular position of the grating reflector, which is defined by the angle between the normal axis of the reflector surface and the incident laser beam, can be determined from the information of optical frequencies of the first-order diffracted beams based on the fact that each of the first-order diffracted beams from the grating reflector has a deterministic angular position corresponding to the optical frequency of each comb mode of the femtosecond laser. Principle of the proposed absolute laser autocollimation and an experimental setup as well as experimental results demonstrating the effectiveness and potentiality of the proposed method are presented.
  • Yindi Cai, Yuan-Liu Chen, Yuki Shimizu, So Ito, Wei Gao
    Journal of Engineering Manufacture 232 11 1893 - 1902 2018年09月01日 [査読有り][通常論文]
     
    The tool–workpiece interactions when a single-point diamond cutting tool with specific tool edge geometry is made to contact with a copper workpiece are evaluated by the molecular dynamics simulations under different temperatures, boundary conditions and model sizes for ultra-precision microcutting and in-process surface form measurement based on a force sensor–integrated fast tool servo. It is confirmed that the proposed multi-relaxation time method is effective to stabilize the workpiece molecular dynamics model over a wide temperature range up to the room temperature under which a practical microcutting and on-machine surface form metrology process are conducted. The boundary condition and model size of the molecular dynamics model are then optimized to make reliable and cost-effective simulations for evaluation of the elastic–plastic transition contact depth and the corresponding contact force when a diamond tool with a practical edge sharpness of up to 30 nm is employed for microcutting and on-machine surface form metrology.
  • Xiuguo Chen, Taku Nakamura, Yuki Shimizu, Chong Chen, Yuan Liu Chen, Hiraku Matsukuma, Wei Gao
    Optics and Laser Technology 103 359 - 366 2018年07月 [査読有り][通常論文]
     
    The high spatial coherence and high stability of a mode-locked femtosecond laser source make it ideal for chromatic confocal imaging. Nevertheless, the high non-smoothness of spectrum of the mode-locked laser source often restricts its application in chromatic confocal probes for a wide range of depth measurement. To eliminate the spectral non-smoothness of the mode-locked laser source, we propose a new chromatic confocal setup in such a way that the reflected laser beam is divided into two sub-beams which are then made to pass through two optical paths with different confocal settings where two identical fiber detectors are placed at the focal position and a defocus position, respectively, for acquiring two confocal signals. An axial response is then obtained from the intensity ratio of the two confocal signals for depth measurement. With the proposed confocal setup, we can expand the working spectral range of a mode-locked laser source to its whole spectrum. Theoretical and experimental investigation have revealed that the developed chromatic confocal probe with the specific mode-locked laser source employed in experiments has a measurement sensitivity of about −4 nm/μm, a depth measurement range of about 40 μm, and a depth resolution of better than 30 nm, respectively.
  • Yuki Shimizu, Taiji Maruyama, Shota Nakagawa, Yuan Liu Chen, Hiraku Matsukuma, Wei Gao
    Measurement Science and Technology 29 7 2018年05月24日 [査読有り][通常論文]
     
    For measurement of a focused laser beam diameter, a new method, referred to as the PD-edge method, in which an edge of an active cell in a photodiode (PD) is directly employed in the same manner as a knife-edge or a knife-pad in the conventional methods, is proposed with the enhancement of the principle of laser autocollimation. In the proposed PD-edge method associated with the laser autocollimation, a focused laser beam diameter can be estimated by using the gradient of output signal from the PD with respect to the change in the angle of incidence of a collimated laser beam made incident to an objective lens. In this paper, the feasibility of the proposed PD-edge method is at first verified in computer simulation. After that, the edge sensitivity characteristic of an active cell in a commercially available PD is investigated in experiments as well as in computer simulation based on the simple edge-transmission region model to search for the possibility of directly employing a commercially available PD for measurement of a focused laser beam diameter. Furthermore, an optical setup is constructed, and some experiments as well as the measurement uncertainty analysis are carried out to verify the feasibility of the proposed PD-edge method.
  • Yuan Liu Chen, Yanhao Xu, Yuki Shimizu, Hiraku Matsukuma, Wei Gao
    Measurement Science and Technology 29 6 2018年05月15日 [査読有り][通常論文]
     
    This paper presents a high quality-factor (Q-factor) quartz tuning fork (QTF) with a glass probe attached, used in frequency modulation tapping mode atomic force microscopy (AFM) for the surface profile metrology of micro and nanostructures. Unlike conventionally used QTFs, which have tungsten or platinum probes for tapping mode AFM, and suffer from a low Q-factor influenced by the relatively large mass of the probe, the glass probe, which has a lower density, increases the Q-factor of the QTF probe unit allowing it to obtain better measurement sensitivity. In addition, the process of attaching the probe to the QTF with epoxy resin, which is necessary for tapping mode AFM, is also optimized to further improve the Q-factor of the QTF glass probe. The Q-factor of the optimized QTF glass probe unit is demonstrated to be very close to that of a bare QTF without a probe attached. To verify the effectiveness and the advantages of the optimized QTF glass probe unit, the probe unit is integrated into a home-built tapping mode AFM for conducting surface profile measurements of micro and nanostructures. A blazed grating with fine tool marks of 100 nm, a microprism sheet with a vertical amplitude of 25 μm and a Fresnel lens with a steep slope of 90 degrees are used as measurement specimens. From the measurement results, it is demonstrated that the optimized QTF glass probe unit can achieve higher sensitivity as well as better stability than conventional probes in the measurement of micro and nanostructures.
  • Yuki Shimizu, Ryo Aihara, Kazuki Mano, Chong Chen, Yuan Liu Chen, Xiuguo Chen, Wei Gao
    Precision Engineering 52 138 - 151 2018年04月 [査読有り][通常論文]
     
    A compact and stable two-axis Lloyd's mirror interferometer based on a new non-orthogonal type of mirror-substrate assembly is designed for fabrication of 100 mm × 100 mm large-area two-dimensional (2D) diffraction scale gratings in a research laboratory or a small-scale manufacturing facility. At first, the required mirror sizes used in the new non-orthogonal type and the conventional orthogonal type are compared based on geometrical analysis. It is identified that the width of the mirror can be reduced to half in the non-orthogonal type while the required mirror height and the expanded laser beam diameter are comparable to those in the orthogonal type. The shorter mirror width makes it possible to design a compact mirror-substrate assembly so that the overall interferometer can be realized in an overall size of 1480 mm × 730 mm for mounting on a commercially available general-purpose 1500 mm × 1000 mm vibration isolation table for use in research laboratories. It is then verified by simulation that the selected laser source and the designed beam expansion assembly, which are the other main parts of the interferometer, are effective for fabricating the designed grating structures. Experiments are also carried out to demonstrate the feasibility of the constructed interferometer for fabricating 100 mm × 100 mm 2D scale gratings with a short period of 1 μm.
  • Yindi Cai, Yuan Liu Chen, Malu Xu, Yuki Shimizu, So Ito, Hiraku Matsukuma, Wei Gao
    Measurement Science and Technology 29 5 2018年03月23日 [査読有り][通常論文]
     
    Precision replication of the diamond tool cutting edge is required for non-destructive tool metrology. This paper presents an ultra-precision tool nanoindentation instrument designed and constructed for replication of the cutting edge of a single point diamond tool onto a selected soft metal workpiece by precisely indenting the tool cutting edge into the workpiece surface. The instrument has the ability to control the indentation depth with a nanometric resolution, enabling the replication of tool cutting edges with high precision. The motion of the diamond tool along the indentation direction is controlled by the piezoelectric actuator of a fast tool servo (FTS). An integrated capacitive sensor of the FTS is employed to detect the displacement of the diamond tool. The soft metal workpiece is attached to an aluminum cantilever whose deflection is monitored by another capacitive sensor, referred to as an outside capacitive sensor. The indentation force and depth can be accurately evaluated from the diamond tool displacement, the cantilever deflection and the cantilever spring constant. Experiments were carried out by replicating the cutting edge of a single point diamond tool with a nose radius of 2.0 mm on a copper workpiece surface. The profile of the replicated tool cutting edge was measured using an atomic force microscope (AFM). The effectiveness of the instrument in precision replication of diamond tool cutting edges is well-verified by the experimental results.
  • Xiuguo Chen, Yuki Shimizu, Chong Chen, Yuan Liu Chen, Wei Gao
    Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics 36 2 2018年03月01日 [査読有り][通常論文]
     
    Delicate control of the initial polarization states of sub-beams incident to the interferometer unit in multibeam Lloyd's mirror interference lithography is of great significance for the fabrication of high-precision two-dimensional (2D) scale gratings. In this work, the optimization of the initial polarization states of incident sub-beams is formulated as a constrained multiobjective optimization problem. A generalized method that allows the incident sub-beams to initially have the general elliptical polarization states in the optimization is proposed based on the multiobjective genetic algorithm. It is demonstrated that the method is capable of delivering ideal initial polarization states with which the cross-interference between the two once-reflected sub-beams on the grating substrate of the interferometer unit can be completely eliminated from the resultant 2D interference fringes. The feasibility of the proposed method is verified through the comparison between the simulated 2D interference fringes and the fabricated 2D scale gratings under the achieved ideal initial polarization states.
  • Yuki Shimizu, Yuki Matsuno, Yuan Liu Chen, Hiraku Matsukuma, Wei Gao
    Nanomanufacturing and Metrology 1 1 45 - 57 2018年03月01日 [査読有り][通常論文]
     
    This paper presents a design and testing of a micro-thermal sensor probe for realizing the proposed concept of non-contact surface defect detection, in which a change in heat flow across the gap between the tip of the micro-thermal sensor probe and a target surface is utilized to recognize the existences of surface defects. In the proposed concept of surface defect detection, the probe tip, where the micro-thermal sensor is embedded, is required to be placed as close as possible to the target surface for highly sensitive surface defect detection. For the purpose, an optical tilt detection assembly based on the laser autocollimation is designed to detect relative tilt of the micro-thermal sensor with respect to a target surface. A sensor probe assembly, in which the fabricated micro-thermal sensor is embedded to the tip of a hollow-shaped piezoelectric actuator by using a homemade sensor mount, is also designed in such a way that the sensor element will face to a target surface. A prototype micro-thermal sensor probe is constructed by integrating the optical tilt detection assembly and the sensor probe assembly, and some experiments have been carried out to verify the basic performances of the prototype micro-thermal sensor probe.
  • Yuki Shimizu, Satoshi Kataoka, Tatsuya Ishikawa, Yuan Liu Chen, Xiuguo Chen, Hiraku Matsukuma, Wei Gao
    Sensors (Switzerland) 18 2 2018年02月 [査読有り][通常論文]
     
    In this paper a new concept of a liquid-surface-based three-axis inclination sensor for evaluation of angular error motion of a precision linear slide, which is often used in the field of precision engineering such as ultra-precision machine tools, coordinate measuring machines (CMMs) and so on, is proposed. In the liquid-surface-based three-axis inclination sensor, a reference float mounting a line scale grating having periodic line grating structures is made to float over a liquid surface, while its three-axis angular motion is measured by using an optical sensor head based on the three-axis laser autocollimation capable of measuring three-axis angular motion of the scale grating. As the first step of research, in this paper, theoretical analysis on the angular motion of the reference float about each axis has been carried out based on simplified kinematic models to evaluate the possibility of realizing the proposed concept of a three-axis inclination sensor. In addition, based on the theoretical analyses results, a prototype three-axis inclination sensor has been designed and developed. Through some basic experiments with the prototype, the possibility of simultaneous three-axis inclination measurement by the proposed concept has been verified.
  • Yuki Shimizu, Masaya Furuta, Yuan Liu Chen, Xiuguo Chen, Hiraku Matsukuma, Wei Gao
    Procedia CIRP 75 355 - 360 2018年 [査読有り][通常論文]
     
    This paper presents an uncertainty analysis of a six-degree-of-freedom surface encoder, which is designed to measure multi-degree-of-freedom motion of a planar motion stage with a single laser beam. Since the surface encoder is composed of an optical sensor head and a two-axis scale grating, optical misalignments in the sensor head and form errors of the scale grating will affect the measurement uncertainty. In this paper, aiming to achieve further accurate measurement of translational displacement, an uncertainty budget table is built for the X-directional translational displacement measurement, while considering the above mentioned uncertainty sources.
  • Error separation method for precision measurement of the Run-Out of a microdrill bit by using a laser scan micrometer measurement system
    Zengyuan Niu, Yuan-Liu Chen, Yuki Shimizu, Hiraku Matsukuma, Wei Gao
    Journal of Manufacturing and Materials Processing 2 1 4  2018年 [査読有り][通常論文]
  • Yuan Liu Chen, Yuki Machida, Yuki Shimizu, Hiraku Matsukuma, Wei Gao
    CIRP Annals 67 1 535 - 538 2018年01月01日 [査読有り][通常論文]
     
    This paper presents a stitching linear-scan method for roundness measurement of small cylinders. Differing from the conventional rotary-scan method by a roundness measuring instrument which suffers from challenges in accurately aligning a cylinder with the rotational datum axis when the cylinder has a small dimension, the stitching linear-scan method, by which the roundness profile of a small cylinder is obtained by stitching a series of arc profiles around the cylinder circumference linearly scanned by a surface form stylus profilometer, makes it easy in alignment of the small cylinder for roundness measurement. Experiments are presented to demonstrate the stitching linear-scan method.
  • Yuki Shimizu, Shuhei Madokoro, Hiraku Matsukuma, Wei Gao
    Journal of Advanced Mechanical Design, Systems and Manufacturing 12 5 96  2018年 [査読有り][通常論文]
     
    This paper proposes a new optical angle sensor, in which a mode-locked laser is employed as the light source, and chromatic dispersion of a collimator objective is utilized to detect the angular displacement of a target of interest. In the proposed method, each of the optical modes in the femtosecond laser beam reflected from the reflector mounted on a target of interest is separated from the others by chromatic dispersion of a collimator objective to generate a group of focused laser beams that can be utilized as the scale for measurement of an angular displacement of the target. By detecting the change in peak frequency in optical spectra obtained by the photodetector, a small angular displacement can be measured. In this paper, as the first step of research, a prototype optical setup is developed, and some basic experiments are carried out to demonstrate the feasibility of the proposed method for measurement of angular displacement.
  • Yuki Shimizu, Kentaro Uehara, Hiraku Matsukuma, Wei Gao
    Journal of Advanced Mechanical Design, Systems and Manufacturing 12 5 97  2018年 [査読有り][通常論文]
     
    This paper presents a newly proposed method referred to as the femtosecond laser diffraction method for measurement of the grating period. The proposed method is established in such a way that a mode-locked femtosecond laser beam is employed as a light source for the traditional laser diffraction method, in which the Littrow configuration is utilized to evaluate grating period. Since the optical modes in a mode-locked laser, which are often referred to as the optical frequency comb, have deterministic mode frequencies with equal intervals in frequency domain, multiple diffracted beams in the same diffraction order can be obtained. By utilizing the number of Littrow angles obtained from the multiple diffracted beams in the same diffraction order, highly accurate measurement of the grating period can be expected. In this paper, as the first step of research, a prototype optical setup with a mode-locked femtosecond laser source is developed, and some basic experiments are carried out to demonstrate the feasibility of proposed method.
  • Keisuke Adachi, Takuma Sugawara, Yuki Shimizu, Yuan Liu Chen, Wei Gao, Eiji Niwa, Yoshihiro Sasaki
    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2017 2017年11月13日 
    This paper presents a design study of an XYZ three-axis micro stage which achieves a size of several cubic centimeters, a millimetric travel range, a nanometric driving resolution and three-axis motion at the same time. In addition, unique leaf springs acting not only as guides for a stage table but also as precision displacement sensors are included in the stage system. The XYZ three-axis micro stage is designed and fabricated. The fabricated stage is designed to have a small size of 25 mm (X) × 25 mm (Y) × 6.5 mm (Z). Furthermore, feasibility of the driving principle of the developed XYZ three-axis micro stage is verified in experiments.
  • Xiuguo Chen, Zongwei Ren, Yuanliu Chen, Yuki Shimizu, Wei Gao
    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2017 2017年11月13日 
    In this work, we establish a three-dimensional (3D) polarization ray-tracing model to trace the evolution of polarization states of incident beams through the corner-cube-like interferometer unit of an orthogonal two-axis Lloyd's mirror interferometer. Compared with the conventional two-dimensional Jones matrix formalism, the 3D polarization ray-tracing model that represents polarization as a three-element electric field vector in the global coordinate system provides an easier approach to trace the polarization evolution. The comparison between the simulated and experimental interference fringes obtained under different combinations of initial polarization states of incident beams verify the feasibility of the established model.
  • Kazuki Mano, Ryo Aihara, Yuki Shimizu, Yuan Liu Chen, Wei Gao
    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2017 2017年11月13日 
    This paper presents an optical setup to fabricate a large-area two-dimensional diffraction grating by using a two-axis Lloyd's mirror interferometer. In order to fabricate large-area gratings, a large collimating lens, which generates a large diameter collimated beam, is integrated into the optical setup. In this paper, an evaluation of the intensity distribution of the collimated beam and an exposure experiment are carried out. In addition, the fabricated grating is measured by an atomic force microscope to evaluate the effectiveness of the developed setup with the large collimating lens.
  • Toshiki Saito, Yuki Machida, Yuki Shimizu, Yuan Liu Chen, Wei Gao
    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2017 2017年11月13日 
    This paper proposes a new surface form measurement method using a scanning type surface profiler for small roll worlpieces, which are used in many industrial fields. In this method, inclination of a workpiece is required to be aligned precisely. For this reason, this paper also proposes a method of measuring the inclination angle of the workpiece without using any other external sensors but using a scanning probe of the surface profiler. In order to confirm the effectiveness of the proposed principles, a measurement system is developed and some experiments are carried out.
  • Kentaro Uehara, Yuki Shimizu, Yuan Liu Chen, Wei Gao
    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2017 2017年11月13日 
    In this paper, a measurement method with a mode-locked laser source for evaluation of grating periods, which is based on the laser diffraction method with the Littrow configuration, is proposed. Optical frequencies of the mode-locked laser, which are referred to as the optical frequency comb, have deterministic mode frequencies with equal intervals in the frequency domain. Since the frequency of each comb mode can be highly stabilized by a high precision external standard, measurement accuracy of the laser diffraction method is expected to be improved. In this study, a prototype optical setup based on the proposed method is developed, and some experiments are carried out to verify the feasibility of the proposed method.
  • Yuki Shimizu, Taku Nakamura, Yuan Liu Chen, Wei Gao
    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2017 2017年11月13日 
    An optical configuration for a confocal microscope employing a mode-locked laser source is proposed in this paper. Due to high illumination efficiency and a highly stable optical frequency of the mode-locked laser, which is traceable with the national standard of frequency and time, the proposed chromatic confocal microscope is expected to achieve a high axial resolution. In this paper, as a first step of research, design study on the optical setup for the prototype chromatic confocal microscope with the mode-locked laser is carried out.
  • Zengyuan Niu, Yuan Liu Chen, Yuki Shimizu, Wei Gao
    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2017 2017年11月13日 
    This paper presents a method for the measurement of relative vertical error motions with respect to vertical misalignment error of a bench center by using an optical micrometer. A roll is used as a reference object and the optical micrometer are employed as a measurement device. In order to achieve an accurate evaluation, a measurement method is proposed to remove the straightness error and the concentricity error of the roll. Through experiment, the relative vertical parallelism error motion with respect to the misalignment error was evaluated to be 1.44 um and the vertical straightness error was evaluated to be 14.01 um.
  • Shuhei Madokoro, Yuki Shimizu, Yuan Liu Chen, Wei Gao
    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2017 2017年11月13日 
    This paper presents a new optical angle sensor, in which a mode-locked laser referred to as an optical frequency comb is employed as the light source. Highly-stable carrier frequency of the optical frequency comb is expected to improve the sensor stability. This angle sensor is designed based on laser autocollimation method, and utilizes the chromatic dispersion of an objective lens to detect angular displacement of a measurement target. A detail of the proposed method is described, followed by some experimental results with the developed prototype optical sensor.
  • Yuan Liu Chen, Yindi Cai, Malu Xu, Yuki Shimizu, So Ito, Wei Gao
    Precision Engineering 50 380 - 387 2017年10月 [査読有り][通常論文]
     
    A method, which is referred to as the edge reversal method, is proposed for precision measurement of the cutting edge radius of single point diamond tools. An indentation mark of the cutting edge which replicates the cutting edge geometry is firstly made on a soft metal substrate surface. The cutting edge of the diamond tool and its indentation mark, which is regarded as the reversal cutting edge, are then measured by utilizing an atomic force microscopy (AFM), respectively. The cutting edge radius can be accurately evaluated through removing the influence of the AFM probe tip radius, which is comparable to the cutting edge radius, based on the two measured data without characterization of the AFM probe tip radius. The results of measurement experiments and uncertainty analysis are presented to demonstrate the feasibility of the proposed method.
  • Xiuguo Chen, Xiuguo Chen, Zongwei Ren, Yuki Shimizu, Yuan Liu Chen, Wei Gao
    Optics Express 25 19 22237 - 22252 2017年09月18日 [査読有り][通常論文]
     
    © 2017 Optical Society of America. Polarization control is of vital importance in two-axis Lloyd’s mirror interference lithography to achieve the preferred interference fringes. In this work, we first establish a three-dimensional polarization ray-tracing model to trace the evolution of polarization states of incident beams through the corner-cube-like interferometer unit of an orthogonal two-axis Lloyd’s mirror interferometer. With the established model, we then derive the optimal combination of initial polarization directions of the incident beams according to the orthogonality of polarization states and the contrast of interference fringes. The comparison between the simulated and experimental interference fringes obtained under different combinations of initial polarization states of incident beams verify the feasibility of the established model and the achieved optimal polarization modulation.
  • Yuan Liu Chen, Zengyuan Niu, Daiki Matsuura, Jung Chul Lee, Yuki Shimizu, Wei Gao, Jeong Seok Oh, Chun Hong Park
    Measurement Science and Technology 28 10 2017年09月07日 [査読有り][通常論文]
     
    In this paper, a four-probe measurement system is implemented and verified for the carriage slide motion error measurement of a large-scale roll lathe used in hybrid manufacturing where a laser machining probe and a diamond cutting tool are placed on two sides of a roll workpiece for manufacturing. The motion error of the carriage slide of the roll lathe is composed of two straightness motion error components and two parallelism motion error components in the vertical and horizontal planes. Four displacement measurement probes, which are mounted on the carriage slide with respect to four opposing sides of the roll workpiece, are employed for the measurement. Firstly, based on the reversal technique, the four probes are moved by the carriage slide to scan the roll workpiece before and after a 180-degree rotation of the roll workpiece. Taking into consideration the fact that the machining accuracy of the lathe is influenced by not only the carriage slide motion error but also the gravity deformation of the large-scale roll workpiece due to its heavy weight, the vertical motion error is thus characterized relating to the deformed axis of the roll workpiece. The horizontal straightness motion error can also be synchronously obtained based on the reversal technique. In addition, based on an error separation algorithm, the vertical and horizontal parallelism motion error components are identified by scanning the rotating roll workpiece at the start and the end positions of the carriage slide, respectively. The feasibility and reliability of the proposed motion error measurement system are demonstrated by the experimental results and the measurement uncertainty analysis.
  • Xiuguo Chen, Yuki Shimizu, Xin Xiong, Yuan Liu Chen, Wei Gao
    Optics Express 25 18 21567 - 21582 2017年09月04日 [査読有り][通常論文]
     
    A new method, in which the wavefronts of the zero-order and the positive and negative first-order diffracted beams from a planar scale grating in Littrow setup are analyzed by a Fizeau interferometer, is proposed to evaluate the Z-directional out-of-flatness as well as the X- and Y-directional pitch deviations of the planar scale grating over a large area. Meanwhile, the surface profile of the reference optical flat in the Fizeau interferometer can also be determined in a much simpler and more efficient approach than the commonly used liquid-flat reference and three-flat test calibration methods. Simulations are presented to verify the feasibility of the proposed method.
  • XIUGUO CHEN, ZONGWEI REN, YUKI SHIMIZU, YUAN-LIU CHEN, AND WEI GAO
    Optics Express 25 19 22237 - 22252 2017年09月 [査読有り][通常論文]
     
    Polarization control is of vital importance in two-axis Lloyd's mirror interference lithography to achieve the preferred interference fringes. In this work, we first establish a three-dimensional polarization ray-tracing model to trace the evolution of polarization states of incident beams through the corner-cube-like interferometer unit of an orthogonal two-axis Lloyd's mirror interferometer. With the established model, we then derive the optimal combination of initial polarization directions of the incident beams according to the orthogonality of polarization states and the contrast of interference fringes. The comparison between the simulated and experimental interference fringes obtained under different combinations of initial polarization states of incident beams verify the feasibility of the established model and the achieved optimal polarization modulation. (C) 2017 Optical Society of America
  • Self-calibration of Fizeau interferometer and planar scale gratings in Littrow setup
    XIUGUO CHEN, YUKI SHIMIZU, XIN XIONG, YUAN-LIU CHEN, AND WEI GAO
    Optics Express 2017年08月28日 [査読有り][通常論文]
  • Yuan Liu Chen, Yuki Shimizu, Jun Tamada, Yukitoshi Kudo, Shuhei Madokoro, Kazuki Nakamura, Wei Gao
    Optics Express 25 14 16725 - 16738 2017年07月10日 [査読有り][通常論文]
     
    A mode-locked laser autocollimator, in which a group of first-order diffracted beams from a grating reflector are detected by an autocollimation unit, has an expanded angle measurement range compared with a conventional autocollimator using a single-wavelength laser source. In this paper, a new optical frequency domain angle measurement method is proposed to increase the visibility of output signal of the mode-locked femtosecond laser autocollimator, which is limited by the overlap of the focused diffracted light spots. The output visibility of a prototype femtosecond laser autocollimator has been increased by the proposed method to approximately 100% over a large range of 21600 arc-seconds.
  • Yuan Liu Chen, Yindi Cai, Keisuke Tohyama, Yuki Shimizu, So Ito, Wei Gao
    Precision Engineering 49 253 - 261 2017年07月 [査読有り][通常論文]
     
    This paper presents auto-tracking single point diamond cutting, which can conduct precision cutting on non-planar brittle material substrates without prior knowledge of their surface forms, by utilizing a force controlled fast tool servo (FTS). Differing from traditional force feedback control machining based on a cantilever mechanism such as an atomic force microscope (AFM) that suffers from low-rigidity and limited machining area, the force controlled FTS utilizes a highly-rigid piezoelectric-type force sensor integrated with a tool holder of the FTS system to provide sufficient stiffness and robustness for force-controlled cutting of brittle materials. It is also possible for the system to be integrated with machine tools to deal with the difficulties in the cutting of large area non-planar brittle materials, which requires not only high machining efficiency but also a high stiffness. Experimental setup is developed by integrating the force controlled FTS to a four-axis ultra-precision diamond turning machine. For the verification of the feasibility and effectiveness of the proposed cutting strategy and system, auto-tracking diamond cutting of micro-grooves is conducted on an inclined silicon substrate and a convex BK7 glass lens, while realizing constant depths of cuts under controlled thrust forces.
  • Yuan-Liu Chen, Yuki Shimizu, Jun Tamada, Yukitoshi Kudo, Shuhei Madokoro, Kazuki Nakamura, Wei Gao
    OPTICS EXPRESS 25 14 16725 - 16738 2017年07月 [査読有り][通常論文]
     
    A mode-locked laser autocollimator, in which a group of first-order diffracted beams from a grating reflector are detected by an autocollimation unit, has an expanded angle measurement range compared with a conventional autocollimator using a single-wavelength laser source. In this paper, a new optical frequency domain angle measurement method is proposed to increase the visibility of output signal of the mode-locked femtosecond laser autocollimator, which is limited by the overlap of the focused diffracted light spots. The output visibility of a prototype femtosecond laser autocollimator has been increased by the proposed method to approximately 100% over a large range of 21600 arc-seconds. (C) 2017 Optical Society of America
  • Zengyuan Niu, Yuan Liu Chen, Daiki Matsuura, Jung Chul Lee, Ryo Kobayashi, Yuki Shimizu, So Ito, Wei Gao, Jeong Seok Oh, Chun Hong Park
    International Journal of Precision Engineering and Manufacturing 18 5 651 - 660 2017年05月01日 [査読有り][通常論文]
     
    This paper presents a precision measurement of the Z-slide vertical error motion of an ultra-precision lathe based on a three-probe measurement method. The vertical error motion of the Z-slide, which is composed of the vertical parallelism error motion and the vertical straightness error motion, is measured by utilizing three displacement measuring probes to scan a self-cut roll workpiece and an accurate straightedge, respectively. A series of factors which could influence the measurement of the vertical error motion, including the error motion of the spindle, the surface form error of the reference object and the horizontal error motion of the Z-slide, are all successfully removed by using the proposed three-probe measurement system with an error separation method. The influence of the gravity induced deflection of the roll workpiece on the measurement of the Z-slide vertical parallelism error motion is also discussed. Experiments were carried out to verify the feasibility of the proposed methods on a three-axis ultra-precision lathe. The vertical straightness error motion was evaluated to be 133 nm with a measurement repeatability of 21 nm and the vertical parallelism error motion was evaluated to be 12.1 μm with a measurement repeatability of 38 nm.
  • Yuki Shimizu, Yuki Matsuno, Yuan Liu Chen, Wei Gao
    International Journal of Automation Technology 11 5 781 - 786 2017年 [査読有り][通常論文]
     
    This paper presents an experimental study on a new concept of a surface defect detection method, in which surface defects will be detected by monitoring a change in heat flow between a micro thermal sensor and a smoothly-finished measuring surface such as magnetic disks, sapphire substrates and so on. In the proposed method, the micro thermal sensor is designed to detect surface defects without any contacts in between them. Since the change in heat flow across the gap is utilized, the method is expected to find out both the convex and concave defects. Searching for the possibility of the non-contact surface defect detection by the micro thermal sensor, in this paper, a simple heat transfer model is established to estimate the change in heat flow due to the change in gap between themeasuring surface and the sensor surface. Some basic experiments are also carried out by using prototype micro thermal sensors, each of which is composed of a pair of electrodes and a thin metal film resistor, fabricated on both the silicon and glass substrates.
  • Yuki Shimizu, Yukitoshi Kudo, Yuan Liu Chen, So Ito, Wei Gao
    Precision Engineering 47 72 - 80 2017年01月01日 [査読有り][通常論文]
     
    A new concept of optical lever for angle measurement having an extended angular measurement range with a mode-locked laser as the light source, which is significantly extended from the conventional photodiode (PD)-type optical levers with a single frequency laser, is proposed. In the proposed concept, a collimated laser beam of the mode-locked laser is made incident to a grating reflector to generate a group of first-order diffracted beams from the grating reflector. Differing from a conventional PD-type optical lever employing a laser beam with a single frequency as the light source, the angle measurement range can be significantly expanded for the sake of the group of widely-spread first-order diffracted beams. In addition, the proposed optical lever has a potential of assuring the traceability of angle measurement by linking it to the optical frequency comb based on the mode-locked laser, which is employed as the national standard of time and frequency. In this paper, as a first step of this research, a mode-locked femtosecond laser is employed as the light source of the proposed optical lever. To distinguish each of the first-order diffracted beams generated with the combination of the mode-locked femtosecond laser and the diffraction grating having a grating period of 1.67 μm, a Fabry-Pérot etalon is employed in the setup of the optical lever to modulate the distance between two neighboring beams in the group of first-order diffracted beams. Experimental setups are developed, and basic experiments are carried out to verify the feasibility of the proposed optical lever.
  • Yuki Shimizu, Sung Ho Jang, Wei Gao
    Measurement: Journal of the International Measurement Confederation 94 934 - 941 2016年12月01日 [査読有り][通常論文]
     
    This paper presents a new optical measuring instrument for multi-dimensional measurement of a diamond cutting tool to be used in diamond turning process. The measuring instrument is composed of a micro-optical probe component for tool edge contour measurement and a Linnik microscope component for tool faces measurement. In the micro-optical probe component, a focused laser beam scans along a tool edge to measure the deviation of the tool edge contour from the scanning path of the laser beam. For further precise tool edge contour measurement with the micro-optical probe component, its spot diameter needs to be optimized. The Linnik microscope component, which is an interferometric microscope having a pair of matched objective lenses in its optical setup, is therefore integrated into the measuring instrument not only to measure tool faces but also to optimize the spot diameter of the focused laser beam in the micro-optical probe component. The optical configuration of the proposed optical measuring instrument is designed, and its prototype composed of the micro-optical probe component and the Linnik microscope component is developed based on an optical cage system. Furthermore, some basic experiments are carried out to verify the feasibility of the developed prototype.
  • Yindi Cai, Yuan Liu Chen, Yuki Shimizu, So Ito, Wei Gao
    2016 IEEE 11th Annual International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2016 156 - 159 2016年11月28日 [査読有り][通常論文]
     
    Molecular dynamics simulations of contact mode form measurement process on a soft substrate with a special surface profile using a diamond AFM tip are preformed to investigate the contact behavior and the surface profile damages or distortions of the measured substrate. The process of contact mode imaging of the AFM can be treated as the process of nano-scratching. The simulation-predicted interaction force, including scratching force and normal force, characterizes the saw-tooth pattern, which is referred to as atomic stick-slips. The shape of measured substrate surface, especially the surface underneath the AFM tip, is distorted by the interaction force between the AFM tip and the substrate surface.
  • Yuki Shimizu, Ryo Aihara, Zongwei Ren, Yuan Liu Chen, So Ito, Wei Gao
    Optics Express 24 24 27521 - 27535 2016年11月28日 [査読有り][通常論文]
     
    This paper presents a detailed analysis on the influence of misalignment errors of optical components in an orthogonal two-axis Lloyd's mirror interferometer, which can fabricate two-dimensional grating structures in a single exposure. In an ideal condition, defect-free two-dimensional grating structures can be fabricated by the interferometer. However, in a real case, visible stripes caused by misalignment errors of the optical components in the interferometer always appear on the fabricated grating structures. In this paper, theoretical analysis and experiments are carried out to analyze the influences of the misalignment errors of the optical components in the orthogonal two-axis Lloyd's mirror interferometer.
  • Zengyuan Niu, Ryo Kobayashi, Yuan Liu Chen, Yuki Shimizu, So Ito, Wei Gao
    16th International Conference on Nanotechnology - IEEE NANO 2016 984 - 985 2016年11月21日 [査読有り][通常論文]
     
    This paper presents nanometrology of an ultraprecision machined surface by using optical sensors. To verify the feasibilities of optical sensors on the measurement of surface profile, different types of fiber-optic sensor and laser micro interferometer are employed to measure the roundness of a ultraprecision machined cone in this paper. Experiments confirmed that the fiber-optic sensor can measure not only the roundness but also the surface roughness of the cone. Experiments also confirm that the measurement of the laser micro interferometer is highly affected by the surface roughness of the cone because of the relative measurement principle of the laser micro interferometer.
  • Zongwei Ren, Ryo Aihara, Yuki Shimizu, So Ito, Yuan Liu Chen, Wei Gao
    16th International Conference on Nanotechnology - IEEE NANO 2016 982 - 983 2016年11月21日 [査読有り][通常論文]
     
    This paper presents the analysis of an orthogonal multi-beam Lloyd's mirror interferometer for fabrication of two-axis gratings, which is employed as a measurement standard. Conventionally, for the fabrication of such complicated micro patterns, ultra-precision turning with a fast tool servo or lithography process with masks has been employed. However, they require long machining or fabrication time. Meanwhile, laser interference lithography such as the Lloyd's mirror interferometer is expected as a candidate for fabrication of such periodic micro patterns. In this paper, a new optical configuration is designed based on the Lloyd's mirror interferometer. In the proposed design, differing from the one in the previous study, two mirrors and a substrate are set to be perpendicular with each other to fabricate two-axis grating patterns having both symmetric profiles and uniform depths over the wide fabrication area, which has been difficult to be achieved in the previous study. A design and fabrication of the optical configuration for the orthogonal multi-beam Lloyd's mirror interferometer, and some experimental results with the interferometer will be reported.
  • Yuki Shimizu, Yuki Matsuno, Yuta Ohba, Wei Gao
    16th International Conference on Nanotechnology - IEEE NANO 2016 978 - 979 2016年11月21日 [査読有り][通常論文]
     
    This paper presents a concept of a micro thermal sensor to be used for defect inspection of a smoothly-finished surface such as a bare wafer or a hard disk. In the proposed concept, existences of the defects on a measurement surface will be detected by scanning the surface with the micro thermal sensor, which is utilized to detect the variation of the thermal flow in-between the sensor surface and the measurement surface. The proposed micro thermal sensor has a possibility of detecting various types of surface defects. An existence of the defect having a convex shape such as an asperity or a particle can be found by detecting a heat generated at the collision between the sensor surface and the tip of the defect. In addition, the thermal sensor is expected to be applied for the inspection of pits or scratches in a concave shape on the smooth surface. When the thermal sensor is placed with respect to the measurement surface with a tiny gap of less than 1 μm, a heat transfer system sensitive against the gap variation will be constructed at the interface between the thermal sensor and the measurement surface becomes a system.
  • Yuan Liu Chen, Yuki Shimizu, Yukitoshi Kudo, So Ito, Wei Gao
    Optics Express 24 14 15554 - 15569 2016年07月11日 [査読有り][通常論文]
     
    A mode-locked laser is employed as the light source of a laser autocollimator, instead of the conventionally employed single-wavelength laser, for an expanded range of tilt angle measurement. A group of the spatially separated diffracted beams from a diffraction grating are focused by a collimator objective to form an array of light spots on the focal plane of the collimator objective where a light position-sensing photodiode is located for detecting the linear displacement of the light spot array corresponding to the tilt angle of the reflector. A prototype mode-locked femtosecond laser autocollimator is designed and constructed for achieving a measurement range of 11000 arc-seconds.
  • Yuan Liu Chen, So Ito, Hirotaka Kikuchi, Ryo Kobayashi, Yuki Shimizu, Wei Gao
    Measurement Science and Technology 27 7 1 - 13 2016年05月31日 [査読有り][通常論文]
     
    This paper presents on-line qualification of the effective diameter of the micro-stylus tip ball of a micro probing system for precision length measurement of micro-features on precision parts by utilizing a set of gauge blocks as the qualification artefact, which is composed by one calibrated gauge block and two supporting gauge blocks that are wrung together for a good mechanical stability. The qualification artefact is aligned side by side with the precision part to be measured for enabling a rapid transfer between the qualification step of the probe two-point tip ball diameter and the length measurement step of the precision part. Based on the proposed setup, on-line qualifications of a micro-stylus with a nominal tip ball diameter of 52.6 μm were carried out by using two methods referred to as Method A and Method B, respectively. Method A is operated by probing the opposite sides of the gap between the two supporting gauge blocks separated by the calibrated gauge block, and Method B is operated by probing the opposite sides of the calibrated gauge block supported by the two supporting gauge blocks. Intensive uncertainty analyses based on the experimental results and the geometrical models were carried out to compare the performances of these two methods. Method A, which was confirmed to be more accurate and faster than Method B, was then employed to measure the width of a micro-gap on a precision part with compensation of the determined effective two-point tip ball diameter.
  • Yuki Shimizu, Siew Leng Tan, Dai Murata, Taiji Maruyama, So Ito, Yuan Liu Chen, Wei Gao
    Optics Express 24 3 2788 - 2805 2016年02月08日 [査読有り][通常論文]
     
    An ultra-sensitive angle sensor employing single-cell photodiodes, which allows tighter focusing leading to a higher angular resolution better than 0.001 arc-second, has been designed based on laser autocollimation. Aiming to investigate the influences of spherical aberrations in the optical system on the sensor sensitivity, an optical model has been established based on wave optics. Computer simulation has been carried out by using the model, and its feasibility has been verified in experiments. In addition, a prototype optical angle sensor has been designed in a compact size of 100 mm × 150 mm, and its measurement resolution has been verified in experiments.
  • Yindi Cai, Yuan Liu Chen, Yuki Shimizu, So Ito, Wei Gao, Liangchi Zhang
    Applied Surface Science 369 354 - 365 2016年 [査読有り][通常論文]
     
    This paper investigates the contact characteristics between a copper workpiece and a diamond tool in a force sensor-integrated fast tool servo (FS-FTS) for single point diamond microcutting and in-process measurement of ultra-precision surface forms of the workpiece. Molecular dynamics (MD) simulations are carried out to identify the subnanometric elastic-plastic transition contact depth, at which the plastic deformation in the workpiece is initiated. This critical depth can be used to optimize the FS-FTS as well as the cutting/measurement process. It is clarified that the vibrations of the copper atoms in the MD model have a great influence on the subnanometric MD simulation results. A multi-relaxation time method is then proposed to reduce the influence of the atom vibrations based on the fact that the dominant vibration component has a certain period determined by the size of the MD model. It is also identified that for a subnanometric contact depth, the position of the tool tip for the contact force to be zero during the retracting operation of the tool does not correspond to the final depth of the permanent contact impression on the workpiece surface. The accuracy for identification of the transition contact depth is then improved by observing the residual defects on the workpiece surface after the tool retracting.
  • Yuan Liu Chen, Yindi Cai, Yuki Shimizu, So Ito, Wei Gao, Bing Feng Ju
    Precision Engineering 43 462 - 467 2016年01月 [査読有り][通常論文]
     
    This paper presents precision on-machine measurement of microwear and microcutting edge chipping of the diamond tool used in a force sensor integrated fast tool servo (FS-FTS) mounted on a three-axis diamond turning machine. A diamond edge artifact with a nanometric sharpness is mounted on the machine spindle with its axis of rotation along the Z-axis to serve as a reference edge artifact. The diamond tool is placed in the tool holder of the FS-FTS to generate cutting motion along the Z-axis. By moving the X-slide on which the FS-FTS is mounted, the reference edge can be scanned by the diamond tool. During the scanning, the Z-directional position of the tool is closed-loop controlled by the FS-FTS in such a way that the contact force between the tool tip and the reference edge is kept constant based on the force sensor output of the FS-FTS. The tool edge contour can be obtained from the scan trace of the tool tip, whose X- and Z-directional coordinates are provided by the output of the linear encoder of the X-slide and that of the displacement sensor in the FS-FTS, respectively. Since the reference edge artifact has a good hardness and a nanometric sharpness to ensure the lateral resolution of measurement, a microwear on the cutting edge of the diamond tool can be indentified from the measured tool edge contour. Experiments of on-machine measurement of tool edge contour and microtool wear are carried out to demonstrate the feasibility of the proposed system.
  • So Ito, Yuan Liu Chen, Yuki Shimizu, Hirotaka Kikuchi, Wei Gao, Kazuhiko Takahashi, Toshihiko Kanayama, Kunmei Arakawa, Atsushi Hayashi
    Precision Engineering 43 525 - 529 2016年01月 [査読有り][通常論文]
     
    A shear mode micro-probing system was constructed for gap measurement of a precision slot die coater with a nominal gap width of 90 μm and a length of 200 mm. A glass micro-stylus with a nominal tip ball diameter of 52.6 μm was oscillated by a tuning fork quartz crystal resonator with its oscillation direction parallel to the measurement surfaces. An on-line qualification setup was established to compensate for the influences of the uncertainty sources, including the water layers on the measurement surfaces. The measurement uncertainty of the measured gap width was estimated to be less than 100 nm.
  • So Ito, Hirotaka Kikuchi, Yuanliu Chen, Yuki Shimizu, Wei Gao, Kazuhiko Takahashi, Toshihiko Kanayama, Kunmei Arakawa, Atsushi Hayashi
    Applied Sciences (Switzerland) 6 5 156  2016年 [査読有り][通常論文]
     
    This paper presents a micro-coordinate measuring machine (micro-CMM) for large-scale dimensional measurement of a micro-slit on a precision die coater by using a shear-mode micro-probe. A glass micro sphere with a nominal diameter of 52.3 μm was attached on one end of a tapered glass capillary tube as a probe tip ball. The micro-slit width of a slot die coater with a nominal slit width of 85 μm was measured by the micro-CMM. The probe tip was placed in the slit for the measurement. The effective working length of the probe was confirmed experimentally to be at least 1 mm. In order to measure the gap width uniformity over the entire slot die length of 200 mm, an air-bearing linear slide with a travelling stroke of 300 mm was employed in the micro-CMM to position the probe along the length direction of the slot die. The angular alignment error and the motion error of the air-bearing linear slide as well as those of the stages for positioning the probe along the direction perpendicular to the length direction of the slot die were investigated for evaluation of the expanded uncertainty of gap width measurement.
  • Jun Tamada, Yukitoshi Kudo, Yuan Liu Chen, Yuki Shimizu, Wei Gao
    Journal of Advanced Mechanical Design, Systems and Manufacturing 10 5 16-00128  2016年 [査読有り][通常論文]
     
    This paper proposes a new optical angle sensor, in which a mode-locked femtosecond laser referred to as the optical frequency comb is employed as the light source for the sensor. By using the optical frequency comb, whose carrier frequency is well stabilized by using an external frequency standard with the uncertainty of 10-11, both the sensor stability and the sensor sensitivity are expected to be improved. In this paper, the angle error caused by the frequency fluctuation of the laser beam is considered in the case of both the mode-locked femtosecond laser and a laser diode, which is a conventional light source for the optical angle sensor. A prototype optical sensor head with the mode-locked femtosecond laser is then fabricated for the angle sensor. Since the light wavelength of the mode-locked femtosecond laser used in this paper is out of the visible range, an alignment method based on laser autocollimation with a retroreflector is introduced to determine the zero-position for the angle sensor. This method is also effective in suppressing the influence of the alignment error such as a cosine error. Some basic experiments are carried out to verify the feasibility of the developed angle sensor with the optical frequency comb.
  • Yindi CAI, Xinghui LI, Ryo AIHARA, Ren ZONGWEI, Yuki SHIMIZU, So ITO, Wei GAO
    Journal of Advanced Mechanical Design, Systems, and Manufacturing 10 5 16-00127  2016年 [査読有り][通常論文]
     
    This paper presents a design study of an optical configuration for the fabrication of a two-dimensional grating, which will be used as a scale in a planar encoder system. For the modified two-axis Lloyd's mirror interferometer, in which major modifications have been made to the conventional one-axis Lloyd's mirror interferometer, computer simulation is carried out based on wave optics. Three-dimensional light intensity distributions of the fringe patterns are calculated to investigate the effect of the polarization modulation. In addition, a relationship between the asymmetry of the cross-sectional profiles of the grating pattern structures and the designed grating pattern period is also investigated. Furthermore, pattern exposure tests have been carried out by using a prototype optical setup for the modified two-axis Lloyd's mirror interferometer.
  • Shigeaki Goto, Minglei Li, So Ito, Yuki Shimizu, Wei Gao
    Journal of Advanced Mechanical Design, Systems and Manufacturing 10 5 16-00134  2016年 [査読有り][通常論文]
     
    A noncontact scanning electrostatic force microscope (SEFM) for surface profile measurement is introduced, and applied to the profile measurement of insulating samples. The SEFM calculates the tip-sample distance with an algorithm named 'dual-height method', and compensates for the fluctuation of the tip-sample distance to obtain accurate surface profile image. Glass and acrylic, which are commonly applied to optical components, are prepared as the insulating samples, and bias voltage is applied to the samples with an electrode clamp. On the glass sample, electrostatic force is observed in the case that the bias voltage of 50 V is on. On the acrylic sample, however, electrostatic force is not observed regardless of the bias voltage. Surface profile measurement of the glass sample is demonstrated. The tip-sample distance image is created with the dual-height method from the data of the tip trajectories and the frequency shift signals obtained through the constant tip-sample interaction scan. The results show that the tip-sample distance is kept larger than 100 nm, which is more than ten times larger than that of conventional noncontact SPMs. The large tip-sample distance brings the SEFM a high robustness against the disturbances from environment, which would cause tip-sample collision in the conventional noncontact SPMs. The same area on the same sample is measured also in an atomic force microscope (AFM) mode, which is realized by setting the bias voltage 0 V. The SEFM image agrees with the AFM image quantitatively, showing that the SEFM with the dual-height method is applicable to noncontact profile measurement of the glass. On the other hand, it is difficult to utilize the SEFM in the profile measurement of the acrylic sample because the electrostatic force on the acrylic is not controllable with the voltage of the electrode clamp.
  • Yuan Liu Chen, Yindi Cai, Yuki Shimizu, So Ito, Wei Gao, Bing Feng Ju
    Journal of Micromechanics and Microengineering 26 2 025002  2015年12月18日 [査読有り][通常論文]
     
    This paper presents a measurement and compensation method of surface inclination for ductile cutting of silicon microstructures by using a diamond tool with a force sensor based on a four-axis ultra-precision lathe. The X- and Y-directional inclinations of a single crystal silicon workpiece with respect to the X- and Y-motion axes of the lathe slides were measured respectively by employing the diamond tool as a touch-trigger probe, in which the tool-workpiece contact is sensitively detected by monitoring the force sensor output. Based on the measurement results, fabrication of silicon microstructures can be thus carried out directly along the tilted silicon workpiece by compensating the cutting motion axis to be parallel to the silicon surface without time-consuming pre-adjustment of the surface inclination or turning of a flat surface. A diamond tool with a negative rake angle was used in the experiment for superior ductile cutting performance. The measurement precision by using the diamond tool as a touch-trigger probe was investigated. Experiments of surface inclination measurement and ultra-precision ductile cutting of a micro-pillar array and a micro-pyramid array with inclination compensation were carried out respectively to demonstrate the feasibility of the proposed method.
  • Zengyuan Niu, Yuanliu Chen, Daiki Matsuura, Ryo Kobayashi, Yuki Shimizu, So Ito, Wei Gao, Jeongseok Oh, Chunhong Park
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月18日 
    This paper presents a measurement method for vertical straightness of a roll workpiece on an ultra-precision lathe. The measurement of vertical straightness of a roll workpiece is directly influenced by the vertical error motions of carriage slide, which is composed of the out-of-straightness error component and the out-of-parallelism error component. The effect by the vertical error motions should be compensated in the measurement of vertical straightness of a roll workpiece. A three-probe method and new algorithms are employed to measure and evaluate both the vertical straightness and the vertical error motions, which are newly introduced. Experiments are carried out on a small roll workpiece.
  • Shigeaki Goto, Minglei Li, Zhigang Jia, So Ito, Yuki Shimizu, Wei Gao
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月18日 
    This paper reports the experimental result of noncontact surface profile measurement of an insulating sample made of glass with the developed electrostatic force microscope (EFM). Noncontact scanning was carried out maintaining the tip-to-sample distance of larger than 100 nm, which significantly reduces the risk of collision between the sample and the tip. The algorism named "dual-height method" calculated the profile image with cancelling the fluctuation of the tip-to-sample distance. The same sample was measured also with the AFM, and the EFM profile images agreed with the AFM profile image quantitatively.
  • Yindi Cai, Yuanliu Chen, Yuki Shimizu, So Ito, Wei Gao, Ying Chen
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月18日 
    This paper presents molecular dynamics simulation on nanoindentation of diamond indenter on a copper workpiece. Surface damages of the workpiece are caused in the contact detection process for ultra-precision fabrication and form measurement of surface by using a force sensor-integrated fast tool servo. Molecular dynamics simulations are carried out in this paper to theoretically investigate the geometries of the damages due to the contact deformation. Taking into consideration of the holding period at the maximum indentation depth between the loading and the unloading processes, the dependence of the indentation geometry on the holding time are observed. Based on the simulation results, physical properties of the workpiece are also analyzed.
  • Yindi Cai, Xinghui Li, Ryo Aihara, Yuki Shimizu, So Ito, Wei Gao
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月18日 
    This paper presents a design study on an optical setup for fabrication of a two-dimensional grating used in encoder systems. By adding major modifications to the conventional one-axis Lloyd's mirror interferometer, a modified two-axis Lloyd's mirror interferometer has been developed. Based on the wave optics, the two-axis interference patterns to be generated by the proposed optical configuration are simulated. To eliminate unwanted distortion of the two-dimensional micro patterns, polarization of the laser beams is controlled by inserting two half wave plates in the optical path. In addition, pattern exposure tests are carried out by using a prototype optical setup.
  • Yuan Liu Chen, Yindi Cai, Keisuke Tohyama, Yuki Shimizu, So Ito, Wei Gao
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月18日 
    This paper presents an experimental investigation of ductile cutting of silicon by using a diamond tool with a negative rake angle. A diamond cutting tool with a zero rake angle is inclined to form a negative rake angle for a better performance in ductile cutting. A high-sensitivity force sensor is integrated with the tool holder for detection of the tool-sample contact and monitoring the thrust force in the cutting process. The unavoidable sample tilt was probed by using the force sensor integrated diamond tool as a stylus, so that microstructures can be directly fabricated along the tilted workpiece. With accurate tilt compensation, a microstructure array with a good uniformity was successfully fabricated on the silicon surface.
  • Jun Tamada, Yukitoshi Kudo, Yuan Liu Chen, Yuki Shimizu, So Ito, Wei Gao
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月18日 
    This paper proposes a new optical angle sensor, in which a mode-locked femtosecond laser referred to as an optical frequency comb is employed as a light source. By using the optical frequency comb whose carrier frequency is well stabilized by using an external frequency standard with an uncertainty of 10 , both the sensor stability and the sensor sensitivity are expected to be improved. In this paper, a prototype optical sensor head with the femtosecond laser for the angle sensor is fabricated. Since the light wavelength of the femtosecond laser used in this paper is out of the visible range, a new alignment method using a retroreflector is introduced to determine the origin position of the angle sensor. In addition, some basic experiments are carried out to verify the feasibility of the developed angle sensor with the optical frequency comb. -11
  • So Ito, Kikuchi Hirotaka, Yuan Liu Chen, Yuki Shimizu, Wei Gao
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月18日 
    A prototype measurement system by using a micro-probe is introduced for the precision measurement of the slit width. The stylus of the micro-probe is consisted of the thermally-pulled capillary glass tube and precision glass ball with 50 μm in diameter, so that the probe tip can be inserted into the inside of the micro-gap. A shear-force detection micro-probing is employed for the precision measurement of the slit width of the slot die coater. The measurement accuracy of the slit width measurement is investigated.
  • Satoshi Kataoka, Tatsuya Ishikawa, Yuki Shimizu, So Ito, Wei Gao
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月18日 
    This paper presents measurement of the angular error motions of a precision linear stage by using a high resolution clinometer in the production process of the stage, where the measurement is repeatedly carried out together with a hand scraping operation for correction of the form errors of the stage guideways. Differing from a conventional autocollimator, the clinometer does not require a reference mirror on the stage since its angle reference is the direction of the gravitational vector. In this paper, two clinometers are employed to measure roll error motion of a linear stage, while eliminating the influences of external vibrations.
  • Minglei Li, Zhigang Jia, So Ito, Yuki Shimizu, Wei Gao
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月18日 
    In this research, a long stroke atomic force microscope (LS-AFM) is developed for surface profile measurement of micro-optics with steep sidewalls. An electrochemically polished tungsten probe with sharpened apex is employed as the AFM probe which provides the effective length of the probe tip more than 100 μm so that the accessibility to the valley part of a deep groove can be realized. The probe tip is vibrated by a tuning fork at their resonance frequency. The probe tapping the sample surface with constant force which is feedback controlled based on the constant frequency shift signal of the tuning fork. The trace of the probe tip in Z direction can be considered as the sample surface profile. Sectional profile measurement of a Fresnel lens is carried out by utilizing the LS-AFM and a commercial optical probe. The comparison of the measurement result demonstrates the effectiveness and the advantage of the developed LS-AFM in profile measurement of micro-optics with steep sidewalls.
  • Yuan Liu Chen, Yuki Shimizu, Yindi Cai, Shu Wang, So Ito, Bing Feng Ju, Wei Gao
    International Journal of Advanced Manufacturing Technology 77 9-12 2257 - 2267 2015年04月 [査読有り][通常論文]
     
    This paper presents a self-evaluation method for sub-micrometer accuracy measurement of the cutting edge contour of a micro diamond tool with a force sensor-integrated fast tool servo (FS-FTS) on an ultra-precision lathe without using any accurate reference artifacts and additional surface form measuring instruments. At first, a series of grooves is cut side by side along the Z-direction over the outer surface of a cylindrical artifact mounted on the lathe spindle by the micro tool of the FS-FTS, which is mounted on the X-directional cross-slide (X-slide) of the lathe, to form a number of sharp line structures. The FS-FTS is then switched to a force feedback control mode for the cutting edge of the micro tool to scan across the line structures as a measuring stylus by moving the artifact with the Z-directional carriage slide (Z-slide) of the spindle. During the scanning, the contact force between the micro tool and the line structures is maintained constant by controlling the X-directional displacement of the cutting tool with the FS-FTS so that the tool cutting edge contour can be obtained from the tool scan trace profile provided by the linear encoder of the Z-slide and the displacement sensor of the FS-FTS. Measurement experiments of a micro tool with a nominal nose radius of 120 μm are carried out to demonstrate the feasibility of the proposed method.
  • Siew Leng Tan, Yuki Shimizu, Takayuki Meguro, So Ito, Wei Gao
    International Journal of Precision Engineering and Manufacturing 16 3 423 - 431 2015年03月 [査読有り][通常論文]
     
    This paper presents the design and construction of a laser autocollimator-based optical sensor for measurement of the tilt angles of a reflector mounted on the guideways or the moving table of a precision linear slide in the production process of the slide, where the measurement is repeatedly carried out together with a hand scraping operation for correction of the form errors of the slide guideways. Differing from a conventional autocollimator, a laser rangefinder unit is integrated with the autocollimation unit for detection of the positions of the reflector, which is necessary for the efficient error correction of the slide guideways. The autocollimation unit and the rangefinder unit share the same light source for a compact optical design. The optical power of the laser beam is first set to be constant for tilt angles measurement. Then the optical power is modulated with a frequency of 66.7 MHz for measuring the position/distance based on the phase shift method. The resolution of the laser autocollimator is confirmed to be 0.2 arc-second over a range of ±50 arc-seconds while the measurement positions can be detected with a resolution of 1 mm by the rangefinder, which satisfies the requirements from production of the slide.
  • ワン シュ, 陳 遠流, 伊東 聡, 清水 裕樹, 高 偉
    精密工学会学術講演会講演論文集 2015 295 - 296 公益社団法人 精密工学会 2015年 
    A self-evaluation method for the cutting edge contour of a micro diamond tool is developed without any accurate reference artifacts or additional measuring instruments by using a force sensor-integrated fast tool servo (FS-FTS) At first, a series of micro grooves are machined with overlaps on the side wall of a roller mounted on the lathe spindle alone Z-direction by using a cutting tool of the FS-FTS, which is mounted on the X-slide of the lathe to form a group of sharp line structures. The cutting tool is then induced to scan across the line structures as a contact probe based on the force feedback control function of the FS-FTS so that the scanning path of the tool can be transferred to the tool edge contour to be measured. In this paper, a principle of the proposed method, a development of the experimental setup and some experimental results are reported.
  • 蔡 引てい, 陳 遠流, 清水 裕樹, 伊東 聡, 高 偉
    精密工学会学術講演会講演論文集 2015 231 - 232 公益社団法人 精密工学会 2015年 
    Contact detection process of ultra-precision surfaces fabrication and form measurement by using a force sensor-integrated fast tool servo will cause the surface damages of a copper workpiece. Based on the study of contact deformation, nanoindentation test is carried out by MD simulation in this paper to theoretically investigate the surface damages due to the contact detection process. Mechanical behaviors of the molecules on the copper workpiece surface during nanoindentation process are observed. In addition, the physical properties of the workpiece are also analyzed in this paper.
  • 陳 遠流, 清水 裕樹, 伊東 聡, 高 偉
    精密工学会学術講演会講演論文集 2015 237 - 238 公益社団法人 精密工学会 2015年 
    This paper presents an in-process measurement technique, which is capable of conducting position identification and dimension characterization of defects, for repair of micro defects by using a fast tool servo with a force sensor. A thrust force map is in-process produced to indicate the cutting status with respect to the positions of the machine slide and the machine spindle measured by linear encoder and rotary encoder, respectively. The position of the defect is detected by observing the thrust force map to determine the location of the abnormal variation in the monitored thrust force. Confirmation and characterization of the defects are conducted by employing the force-controlled tool to measure the sectional profile of the defective microstructures. The identified position and the characterized dimension are fed back to carry out repair which can be thus with exact tool setting position and accurate repair path. Experiments were carried out on a nikel cylindrical workpiece with a diameter of 55 mm fabricated by using a micro diamond tool. Defects, with dimension on the order of 1 μm among a cut microstructure array over the outer surface of the cylindrical workpiece, were in-process detected and repaired to confirm the feasibility of the proposed method.
  • Bin Xu, Yuki Shimizu, So Ito, Wei Gao
    Precision Engineering 39 152 - 160 2015年01月01日 [査読有り][通常論文]
     
    This paper presents surface-profiling based gear pitch deviation measurement for an involute spur gear. A rotary profiling system, which consists of an air-bearing spindle and a displacement sensor with a diamond stylus, is employed to measure gear pitch deviation. In measurement of gear pitch deviation, an eccentric error between a gear axis and a motion axis of the rotary stage in the profiling system would affect accuracy of gear profile measurement. In this paper, at first, the influence of the eccentric error on measurement of gear pitch deviation is estimated in computer simulation based on a geometric model of the profiling system. After that, a new scanning method named "opposite-direction dual scanning method" is proposed so that a steep profile of gear flank surface with a local slope of up to 90° can be measured by the developed rotary profiling system. For compensating distortions in the measured gear tooth profile, which are induced not only by the eccentric error but also by a probe offset introduced by the proposed scanning method, a self-calibration and compensation method is applied. To verify the feasibility of the proposed method, measurement of gear pitch deviation of a master involute spur gear with a certificate data is carried out. Measurement uncertainty of the proposed method is also analyzed.
  • Yuan Liu Chen, Shu Wang, Yuki Shimizu, So Ito, Wei Gao, Bing Feng Ju
    Precision Engineering 39 134 - 142 2015年01月01日 [査読有り][通常論文]
     
    This paper presents an in-process measurement method, which is capable of conducting real-time position identification and on-machine profile characterization of micro-defects in defective microstructures by using a fast tool servo with a force sensor (FS-FTS) on an ultra-precision lathe. A real-time thrust force map is captured in the process of cutting the microstructures by the FS-FTS to indicate the cutting status with respect to the cutting tool position in the coordinate system of the lathe. Based on the thrust force map, the positions of the defects are identified in real time from the locations of the abnormal variations in the map associated with the occurrences of the defects. Characterization of the defects is then conducted by employing the force-controlled cutting tool as the measuring probe to measure the sectional profiles of the defective microstructures. The identified positions and the characterized profiles of the defects are then fed back to carry out the repair fabrication of the defective microstructures with an accurate tool path. Experiments of in-process detection and repair of the micro-defects in the microstructures over the outer surface of a roll mold were carried out to confirm the feasibility of the proposed method.
  • Yuki Shimizu, Yuta Ohba, Wei Gao
    International Journal of Automation Technology 9 3 291 - 296 2015年 [査読有り][通常論文]
     
    This paper presents an investigation on the sensitivity of a thermal sensor, which will be used as a contact detection sensor for surface defect inspections. In the proposed concept, frictional heat generated at a slight contact between a defect on a measuring surface and the thermal sensor will be utilized to find out existences of defects on the measuring surface. The frictional heat will be detected as a deviation of the electrical resistance of the sensing element in the thermal sensor. According to the principle, the sensor temperature will increase at the contact with defects. However, in the previous research by the authors, the sensor temperature was found to decrease at the contact with the glass-ball probe, whose tip diameter was on the order of several-ten μm. Following the experiments in the previous study, in this paper, further experimental investigation is carried out by employing an AFM probe as a nano-tip probe so that the sensitivity of the thermal sensor as a contact detection sensor for nanoscale defects inspection can be verified. Furthermore, a possible mechanismof the heat flow at the contact interface, which can explain the results observed in these experiments, is also introduced.
  • Xinghui Li, Yindi Cai, Ryo Aihara, Yuki Shimizu, So Ito, Wei Gao
    Proceedings of SPIE - The International Society for Optical Engineering 9524 2015年 [査読有り][通常論文]
     
    This paper presents a fabrication method of two-dimensional micro patterns for adaptive optics with a micrometric or sub-micrometric period to be used for fabrication of micro lens array or two-dimensional diffraction gratings. A multibeam two-axis Lloyd's mirror interferometer is employed to carry out laser interference lithography for the fabrication of two-dimensional grating structures. In the proposed instrument, the optical setup consists of a light source providing a laser beam, a multi-beam generator, two plane mirrors to generate a two-dimensional XY interference pattern and a substrate on which the XY interference pattern is to be exposed. In this paper, pattern exposure tests are carried out by the developed optical configuration optimized by computer simulations. Some experimental results of the XY pattern fabrication will be reported.
  • An ultra-precision Electronic Clinometer for Measurement of Small Inclination Angles
    Siew-Leng Tan, Satoshi Kataoka, Tatsuya Ishikawa, So Ito, Yuki Shimizu, Yuanliu Chen, Wei Gao, Satoshi Nakagawa
    Journal of the Korean Society of Manufacturing Technology Engineers 23 6 539 - 545 2014年12月 [査読有り][通常論文]
  • Xinghui Li, Yuki Shimizu, Takeshi Ito, Yindi Cai, So Ito, Wei Gao
    Optical Engineering 53 12 2014年12月 [査読有り][通常論文]
     
    A multiprobe surface encoder for optical metrology of six-degree-of-freedom (six-DOF) planar motions is presented. The surface encoder is composed of an XY planar scale grating with identical microstructures in X- and Y-axes and an optical sensor head. In the optical sensor head, three paralleled laser beams were used as laser probes. After being divided by a beam splitter, the three laser probes were projected onto the scale grating and a reference grating with identical microstructures, respectively. For each probe, the first-order positive and negative diffraction beams along the X- and Y-directions from the scale grating and from the reference grating superimposed with each other and four pieces of interference signals were generated. Three-DOF translational motions of the scale grating Δx, Δy, and Δz can be obtained simultaneously from the interference signals of each probe. Three-DOF angular error motions θX, θY, and θZ can also be calculated simultaneously from differences of displacement output variations and the geometric relationship among the three probes. A prototype optical sensor head was designed, constructed, and evaluated. Experimental results verified that this surface encoder could provide measurement resolutions of subnanometer and better than 0.1 arc sec for three-DOF translational motions and three-DOF angular error motions, respectively. © 2014 Society of Photo-Optical Instrumentation Engineers.
  • Jung Chul Lee, Yuki Shimizu, Wei Gao, Jeongseok Oh, Chun Hong Park
    Precision Engineering 38 4 839 - 848 2014年10月 [査読有り][通常論文]
     
    This paper presents on-machine evaluation of surface form error components of a large-scale roll workpiece, including the out-of-roundness, the out-of-straightness, the taper angle and the diameter deviation, on a drum roll lathe. A pair of capacitive-type displacement probes is mounted on the carriage slide to target the two sides of the roll workpiece mounted on the spindle, which has a length of 2000 mm, a diameter of 320 mm and a mass of 350 kg. The outputs of the probes are employed to accurately evaluate the surface form error components through separating the influences of the motion errors of the spindle and the carriage slide of the lathe. It has been difficult to apply the reversal error-separation method for measurement of the out-of-roundness component of such a large workpiece because it is difficult to reverse the workpiece with respect to the spindle on the lathe due to its large size and heavy mass. An improved reversal operation technique, in which the spindle is rotated with respect to the stationary roll workpiece being held by a crane, is therefore proposed to solve this problem. Measurement uncertainty analysis is carried out to verify the reliability of the new technique for on-machine evaluation of the out-of-roundness component. The out-of-straightness component and the taper angle component of the roll workpiece are then evaluated by using a previously developed method. A simple and effective algorithm for evaluation of the diameter deviation component is also presented. © 2014 Elsevier Inc.
  • Zhigang Jia, So Ito, Shigeaki Goto, Keiichiro Hosobuchi, Yuki Shimizu, Wei Gao
    Measurement Science and Technology 25 9 2014年09月01日 [査読有り][通常論文]
     
    The influence of drifts on the measurement results of an electrostatic force microscope (EFM) based on a dual-height method for surface profile measurement is analyzed. Two types of drifts and their influence on the EFM measurement are discussed by computer simulation. It is figured out that the mechanical drift has a larger impact compared to the resonance frequency drift for the specific EFM with the conventional round-trip scan mode. It is also verified that the profile reconstruction algorithm of the dual-height method for separating the electric property distribution and the surface profile of the surface has an effect of magnifying the drift error in the result of surface profile measurement, which is a much more significant measurement of uncertainty sources for the developed EFM compared with an ordinary scanning probe microscope (SPM). A new vertical reciprocating scan (VRS) mode is then employed to reduce the influences of the drifts. The feasibility of the VRS mode is demonstrated by computer simulation and measurement experiments with a diffraction grating. © 2014 IOP Publishing Ltd.
  • Yuki Shimizu, Takeshi Ito, Xinghui Li, Woojae Kim, Wei Gao
    Measurement Science and Technology 25 9 2014年09月01日 [査読有り][通常論文]
     
    This paper presents a design study of a four-probe optical sensor head for a three-axis surface encoder with a mosaic scale grating. As the mosaic scale grating, multiple two-dimensional reflective-type scale gratings are aligned in a matrix on a plane so that measurement ranges of the three-axis surface encoder along the X- and Y-axes can be extended. An optical layout for a four-probe unit, which consists of a laser diode and two beam splitters, was designed based on geometrical optics so that four probes aligned in the matrix can be generated. The designed four-probe unit was integrated into the optical sensor head of the three-axis surface encoder. Interference signals generated by the superimposition of diffraction beams from the XY gratings were utilized in the three-axis surface encoder so that the translational displacement motions of the mosaic scale grating along the X-, Y- and Z-axes can be detected simultaneously by each probe in the four probes. Experiments were carried out to verify the feasibility of both the designed four-probe optical sensor head and the proposed concept of the mosaic scale grating for expanding the measurement range of the three-axis surface encoder along the X- and Y-directional primary axes of motion. Measurement sensitivity of each probe was compared, and its compensation was carried out by linear matrix calculations. Measurement resolution and nonlinearity of each probe were also investigated. In addition, XYZ-directional translational motions of a linear stage when a long-range translational motion along the X-axis was given to the mosaic scale grating were measured by stitching the measured results by the four probes. © 2014 IOP Publishing Ltd.
  • So Ito, Ryo Aihara, Woo Jae Kim, Yuki Shimizu, Wei Gao
    Advanced Optical Technologies 3 4 435 - 440 2014年08月01日 [査読有り][通常論文]
     
    Three-axis vibration measurement of the linear air-bearing stage demonstrated by utilizing the method of the multi-axis laser interferometer is discussed. In order to detect the X-Y-Z directional vibration of the positioning stage table simultaneously, two-dimensional XY gratings are utilized as the scale grating and the reference grating of the interferometer. The X- and Y-directional positive and negative first-order diffracted beams are superimposed to generate the interference signals on the photodetectors. When the multi-axis vibration is applied to the scale grating, the intensities of the interference signals in X- and Y-directions varied corresponding to the vibration of the scale grating. Consequently, three-axis vibrations of the scale grating can be calculated by processing the X- and Y-directional positive and negative first-order interference signals. In this paper, a three-axis vibrometer based on the grating-interferometer has been developed for measurement of the positioning stage table vibration. The detection method of the vibration based on the Doppler frequency shift has been demonstrated. As an application of the multi-axis grating-interferometric vibrometer, multi-axis vibrations of the linear air-bearing stage are measured by using the developed vibrometer.
  • Yuan Liu Chen, Wei Gao, Bing Feng Ju, Yuki Shimizu, So Ito
    Measurement Science and Technology 25 6 2014年06月 [査読有り][通常論文]
     
    By using the secondary function of a force sensor integrated fast tool servo (FTS) for surface profile measurement, the three-dimensional tip position of a micro-cutting tool in the FTS with respect to the fabricated microstructures was measured without using any additional instrument for realizing the concept of relay fabrication of microstructured surface. It was verified from the experiments for testing the basic performances of tool tip position measurement that the delay of the force feedback control loop of the FTS was a big factor influencing the position measurement accuracy. A bidirectional scanning strategy was then employed to reduce the position measurement error due to the delay of the feedback control loop. Tool tip position measurement experiments by using micro-tools with a nose radius of 100μm for relay fabrications with sub-micrometer accuracies, including stitching fabrication of a micro-groove line array and filling fabrication of a microlens lattice pattern, were carried out to demonstrate the feasibility of the tool position measurement method. © 2014 IOP Publishing Ltd.
  • Yuki Shimizu, Wenjian Lu, Yuta Ohba, Wei Gao
    Measurement Science and Technology 25 6 2014年06月 [査読有り][通常論文]
     
    This paper presents a feasibility study on the concept of a thermal contact sensor that detects nanometre-scale defects on smoothly finished surfaces such as bare silicon wafers, magnetic disks and so on. The contact sensor has a thermal element, which is composed of thin-film structures with a thermally sensitive area of several tens of μm on its tip surface. In the proposed concept, the thermal element detects the existence of asperity-type defects on smooth surfaces by capturing frictional heats due to slight contacts between the thermal element surface and defects. During the defect detection, a gap between the thermal element surface and the smooth surface being rotated by a precision spindle would be maintained. By monitoring deviation of the electrical resistance of the thermal element while scanning the contact sensor across the rotating surface, defects on the target surface can be detected. In this paper, a fabrication process for the thermal element has been designed based on the photolithography process, and the first prototype of the thermal element has been fabricated. Results of laser exposure tests have revealed that the fabricated thermal element can detect a rate of heat supply of 10μW, which is the same order as the rate of heat supply assumed to be generated at defect detection by the contact sensor. In addition, results of contact detection tests have confirmed the feasibility of the fabricated thermal element as a contact detection sensor. © 2014 IOP Publishing Ltd. 2
  • Yuxin Peng, So Ito, Yuki Shimizu, Toyohiro Azuma, Wei Gao, Eiji Niwa
    Sensors and Actuators, A: Physical 211 89 - 97 2014年05月01日 [査読有り][通常論文]
     
    A Cr-N thin-film displacement sensor with a millimeter-scale measurement range is proposed for nanometric positioning of a developed micro-stage. The sensor was designed in a compact size of 14 mm (L) × 1 mm (W) × 0.1 mm (T). A leaf spring made of zirconium oxide, which was employed as the support and guideway of the moving plate in the micro-stage, was employed as the substrate of the sensor. The Cr-N thin film was sputtered directly on one side of the leaf spring to form a Wheatstone bridge circuit with four active strain gauges. Based on the finite element method (FEM), it was verified that both tensile and compressive strains could be generated on the same side of the leaf spring. In order to arrange the strain gauges at the appropriate strain areas of the leaf spring, the relationship between the geometric parameters and the strain distribution of the leaf spring was also investigated by FEM. Experimental results have indicated that the developed sensor had a good linearity and a high sensitivity, which would be applicable for detection of the nanometric displacement of the micro-stage. © 2014 Elsevier B.V. All rights reserved.
  • S. H. Jang, Y. Shimizu, S. Ito, W. Gao
    Journal of Sensors and Sensor Systems 3 1 69 - 76 2014年03月28日 [査読有り][通常論文]
     
    This paper presents a micro optical probe, which is employed to evaluate edge contours of single point diamond tools with a size in a range of several millimetres. The micro optical probe consists of a laser source with a wavelength of 405 nm, an objective lens with a numerical aperture of 0.25, a photodiode for measurement, and a compensating optical system including another photodiode for compensation of laser intensity. A collimated laser beam, which is divided by a beam splitter in the compensating optical system, is focused by the objective lens so that the focused spot can be used as the micro optical probe. The micro optical probe traces over an edge contour of an objective tool while the signals of both the two photodiodes are monitored. The output of the photodiode for measurement is compensated by using that of the photodiode for laser intensity compensation to eliminate the influence of the laser instability. The signal of the photodiode for measurement is used to define the deviation of edge contour within the diameter of the micro optical probe. To verify the feasibility of the developed optical probe, the optical system was mounted on a diamond turning machine, and some experiments were carried out. Two types of edge contours of the diamond tools having a straight cutting edge and a round cutting edge were measured on the machine.
  • Junguo Xu, Yuki Shimizu, Masaru Furukawa, Jianhua Li, Yuichiro Sano, Toshiya Shiramatsu, Yuichi Aoki, Hiroyuki Matsumoto, Kenji Kuroki, Hidekazu Kohira
    IEEE Transactions on Magnetics 50 3 114 - 118 2014年03月 [査読有り][通常論文]
     
    The fundamental performance of contact/clearance sensor, namely embedded contact sensor (ECS), is addressed in this paper. Both simulation and experiment results revealed that ECS is a promising sensor for low clearance and high reliability at subnanometer regime. The ECS dc signal intrinsically comes from multiple sources including TFC heater, air-bearing surface cooling, and friction heating at head/disk contact. Both ECS dc and ac signals detect head/disk contact. The dc signal comes from the sensor resistance change due to friction heating at contact, but the ac signal is dominated by spacing modulation caused by air-bearing vibration, and partially from the pulse-like friction heating. ECS ac signal responds significantly to disk microwaviness at narrow clearance region. Furthermore, ECS could detect asperities, pit, and lube mogul. The mechanism for asperity detection is friction heating. The mechanism for pit detection is worse cooling when sensor flying over the pit. That for mogul detection is better cooling at narrower spacing when the sensor is flying over the mogul. © 2014 IEEE.
  • Gaofa He, Zhigang Jia, So Ito, Yuki Shimizu, Wei Gao
    Open Electrical and Electronic Engineering Journal 8 1 342 - 347 2014年 [査読有り][通常論文]
     
    For measuring the surface profile of many micro-optical components with complicated shapes, which are made of non-conductive material, the electrostatic force microscopy (EFM) was recommended. The relationship between the polarization force and the tip-to-sample distance was analyzed based on dielectric polarization theory. The prototype of the scanning electrostatic force microscopy was built. The force curves of different samples with different materials and surface shapes were detected by the EFM prototype. Both theoretical analysis and the experimental results demonstrated that the EFM system can be used to measure the surface profile of non-conductor.
  • So Ito, Daiki Matsuura, Takayuki Meguro, Shigeaki Goto, Yuki Shimizu, Wei Gao, Shigeru Adachi, Kyohei Omiya
    Journal of Advanced Mechanical Design, Systems and Manufacturing 8 4 2014年 [査読有り][通常論文]
     
    Ceramics materials have excellent mechanical characteristics such as high-stiffness, low-thermal expansion, wear resistance and light weight. Owing to those characteristics, the ceramics parts have been used for the sliding part of the precision positioning stages. However, it is difficult for the ceramics workpieces to achieve the desired form accuracy in once machining process because of the brittleness of the ceramics materials. The compensation of the form error is processed by the manual procedures in general, so it requires a skill of the operator and a great deal of time. In order to realize the automation of the error compensation, it is necessary to measure the workpiece form on the machine tool. In this study, an on-machine form measurement system using a laser displacement sensor having nanometric accuracy is introduced for the surface form measurement of the precision ceramics workpieces. The laser displacement sensor is mounted on the tool post of the ultra-precision polishing machine to realize the on-machine measurement of the ceramics workpieces. By using two horizontal linear slides of the machine tool, the laser displacement sensor can scan the surface of the workpiece with sub-micrometric motion accuracy. Consequently, three-dimensional continuous surface form of the precisely machined ceramics workpiece can be obtained in non-contact condition. In order to evaluate the measurement accuracy of the constructed system, the experiments to investigate stability and motion accuracy were conducted, and then the form measurement of the precision ceramics parts is carried out by using the proposed measurement system.
  • Wei Gao, Bin Xu, Toshiki Takeishi, Yuki Shimizu, So Ito
    Chinese Journal of Mechanical Engineering (English Edition) 27 1 14 - 22 2014年01月 [査読有り][通常論文]
     
    Microstructured roll workpieces have been widely used as functional components in the precision industries. Current researches on quality control have focused on surface profile measurement of microstructured roll workpieces, and types of measurement systems and measurement methods have been developed. However, low measurement efficiency and low measurement accuracy caused by setting errors are the common disadvantages for surface profile measurement of microstructured roll workpieces. In order to shorten the measurement time and enhance the measurement accuracy, a method for self-calibration and compensation of setting errors is proposed for surface profile measurement of microstructured roll workpieces. A measurement system is constructed for the measurement, in which a precision spindle is employed to rotate the roll workpiece and an air-bearing displacement sensor with a micro-stylus probe is employed to scan the microstructured surface of the roll workpiece. The resolution of the displacement sensor is 0.14 nm and that of the rotary encoder of the spindle was 0.15″. Geometrical and mathematical models are established for analyzing the influences of the setting errors of the roll workpiece and the displacement sensor with respect to the axis of the spindle, including the eccentric error of the roll workpiece, the offset error of the sensor axis and the zero point error of the sensor output. Measurement experiments are carried out on a roll workpiece on which periodic microstructures are a period of 133 μm along the circumferential direction. Experimental results demonstrate the feasibility of the self-compensation method. The proposed method can be used to detect and compensate the setting errors without using any additional accurate artifact. © Chinese Mechanical Engineering Society and Springer-Verlag Berlin Heidelberg 2014.
  • X. Li, W. Gao, Y. Shimizu, S. Ito
    CIRP Annals-Manufacturing Technology 63 1 461 - 464 2014年 [査読有り][通常論文]
     
    A new two-axis Lloyd's mirror interferometer based on multi-beam interference is proposed. A square grating substrate with normal in the Z-axis is placed edge to edge with two rectangular mirrors with normals parallel to the XZ-plane (X-mirror) and the YZ-plane (Y-mirror), respectively. The angle between the substrate and each mirror is set to be larger than 90°, so that the beams reflected by the mirrors can be superimposed with the direct beam at the substrate to produce two-dimensional (2D) diffraction grating structures in a single exposure. Sub-micron pitched 2D hole grating structures were fabricated and evaluated. © 2014 CIRP.
  • Sung Ho Jang, Yuki Shimizu, So Ito, Wei Gao
    Journal of Advanced Mechanical Design, Systems and Manufacturing 8 4 2014年 [査読有り][通常論文]
     
    This paper proposes a non-contact and on-machine measurement method for evaluating tool edge geometry. In the proposed method, a focused laser beam having a diameter of several micrometres traces over the tool edge. By utilizing a light intensity of the laser beam passed around the tool rake face, the gap between the centre of the optical axis of the focused laser beam and the tool edge can be obtained. By combining the measured gap and the information on the XY positions of the focused laser beam, the tool edge contour can be evaluated. In the proposed method, stability of the laser power emitted from a light source would affect measurement accuracy of the tool edge contour. A modified optical design was therefore applied to the evaluation system so that a laser power drift and influences of common-mode noise could be compensated in real time. A modified evaluation system consisting of a laser diode, a beam splitter, a pair of lenses and two photodiodes was developed. Experiments were carried out to test the basic performances of the developed evaluation system with the modified optical design. Possible sources of measurement errors in the tool edge contour evaluation were also discussed. Furthermore, computer simulation was carried out to confirm measurement resolution of the developed system along the tool edge contour.
  • Yuki Shimizu, Yuta Ohba, Wei Gao
    Journal of Advanced Mechanical Design, Systems and Manufacturing 8 4 2014年 [査読有り][通常論文]
     
    A fabrication process of a contact detection sensor, which is thermally-sensitive thin film sensor referred to as a thermal contact sensor to be used for a surface defect inspection, is designed based on photolithography process. The existence of a small defect, the size of which is on the order of several-ten nanometers, would be detected by capturing frictional heat generated at the contact between the thermal contact sensor and the defect. The thermal contact sensor is therefore designed to detect small quantity of frictional heat, the rate of heat supply of which is estimated to be on the order of microwatts. In this paper, followed by the fabrication of the first prototype thermal contact sensor in the previous study, the structure of the thermal contact sensor is modified to make the thermally-sensitive area of the thermal contact sensor to be located at its top surface. For further stable fabrication of a thermal contact sensor, lift-off process with a positive resist is also introduced in the sensor fabrication process. Experiments are carried out to verify the feasibility of the fabricated second prototype thermal contact sensor. In addition, aiming to improve sensitivity of the thermal contact sensor, the relationship between the sensor sensitivity and the sensor bias voltage is investigated in experiments. Furthermore, FEM simulation is carried out to estimate the increase of the sensor temperature due to a self-heating effect by the bias voltage applied to the thermal contact sensor, since the sensor temperature deviation could affect the sensitivity of the thermal contact sensor.
  • Keiichiro Hosobuchi, Zhigang Jia, So Ito, Yuki Shimizu, Wei Gao
    Journal of Advanced Mechanical Design, Systems and Manufacturing 8 4 2014年 [査読有り][通常論文]
     
    This paper presents a method for the measurement of the contact potential difference (CPD) and material distribution on the sample surface by using a scanning electrostatic force microscope (SEFM). In SEFM, the surface profile is evaluated by applying an electrostatic force generated between the probe tip and the sample surface. The amount of electrostatic force relies on both the surface profile and the surface material distribution. To selectively extract the quantitative surface profile, the calculation method to cancel the effect of surface material distribution towards detected electrostatic force is applied in the profile measurement using SEFM. On the other hand, by utilizing the variation of electrostatic force affected by the material distribution, and applying the quantitative profile measurement principle, CPD measurement can be realized. Since the intensity of electrostatic force generated between the probe and the sample surface will rely on the differences of the CPD, the CPD can be calculated by using the frequency shifts of the probe oscillation when two different bias voltages are applied between the tip and the sample. In this paper, firstly, the effect of the surface material distribution on the profile measurement result is reported. The profile measurement result of a sample which consists of two or more materials showed a similar profile with the measurement result obtained by a commercial AFM, which demonstrates that the proposed principle is effective in quantitative measurement of surface profile. Then, the detection sensitivity of the CPD corresponding to the experimental conditions has been confirmed by simulation. In addition, the basic characteristic of the CPD measurement system has been evaluated.
  • Zhigang Jia, Keiichiro Hosobuchi, So Ito, Yuki Shimizu, Wei Gao
    Journal of Advanced Mechanical Design, Systems and Manufacturing 8 4 2014年 [査読有り][通常論文]
     
    A new scan mode referred to as the feed-forward controlled unidirectional scan mode is employed to improve the accuracy of surface profile measurement of micro-optics in a scanning electrostatic force microscope (SEFM) instead of the conventional feedback controlled bidirectional scan mode. Two kinds of error sources, the positioning deviation of the X-stage and the frequency shift detection delay due to the lock time of the PLL circuit, are analyzed theoretically. It is verified that large profile measurement error can be introduced by the error sources when steep structures are included in the surface profile. It is also demonstrated that the feed-forward controlled unidirectional scan mode can remove the influence of the positioning deviation error component. It can also reduce the influence of the frequency shift detection delay error component by shortening the lock time of the PLL circuit and increasing the bandwidth of the PLL circuit through a feed-forward control strategy of the scan traces with the PI controller of the Z-scanner turned off. Experiments of surface profile measurement are carried out on two diffraction grating samples with different grating structures. The feasibility of the new scan mode is confirmed by the experimental results.
  • Xinghui Li, Yuki Shimizu, So Ito, Wei Gao
    International Journal of Precision Engineering and Manufacturing 14 11 1979 - 1988 2013年11月 [査読有り][通常論文]
     
    This paper presents a cost-effective fabrication method of grating structures with a period of sub-μm for surface encoders. By employing an inexpensive and compact blue laser diode, which has a wavelength of 405 nm and is used in Blu-ray disc drives, a Lloyd's mirror interferometer has been developed to carry out laser interference lithography for the fabrication of grating structures. Experimental results showed that the developed fabrication system is capable of fabricating grating structures with a pitch of 570 nm. The relative pitch deviation is confirmed to be approximately 1%, which meets the requirement for the scale grating used in a surface encoder. The influence of the limited coherence length of the laser diode on the fabrication area of the grating structures has also been investigated. To expand the fabrication area of the grating structure, a laser source, which has a wavelength of 405 nm and a longer coherence length with a mode selection cavity, is employed in the fabrication system. It has been verified by experiments that the fabrication area of the sub-μm periodic grating structures can be expanded to 300 mm with the laser source. © 2013 Korean Society for Precision Engineering and Springer-Verlag Berlin Heidelberg. 2
  • Yuki Shimizu, Wenjian Lu, Yuta Ohba, Wei Gao
    International Journal of Automation Technology 7 6 708 - 713 2013年11月 [査読有り][通常論文]
     
    This paper presents an experimental study on a thermal element, which is designed to be used as a sensing device that detects a small amount of frictional heat due to a contact with nanometre-scale defects on smoothly-finished surfaces. A prototype of the thermal element, which is a thin-film resistance, is fabricated by using photolithography processes, and its sensitivity on the contact detection is investigated through some experiments, in which the thermal element is scratched by a micro-sphere controlled by PZT actuator in both X- and Z-directions so that a contact between the thermal element and defects can be simulated. Influences of an interference height and relative velocity between the thermal element and the target surface on the output of the thermal element at the contact detection are verified.
  • So Ito, Zhigang Jia, Shigeaki Goto, Keiichiro Hosobuchi, Yuki Shimizu, Gaofa He, Wei Gao
    International Journal of Automation Technology 7 6 714 - 719 2013年11月 [査読有り][通常論文]
     
    A scanning probe microscope with an electrostatic force probe has been introduced for the dimensional measurement of the surface profile measurement. Since the intensity of the electrostatic force is strongly depended on the distance between a probe and the sample surface, the electrostatic force probe can be used for the measurement of the surface profile in non contact condition. In order to detect the electrostatic force between the probe tip and the sample surface, a method of the frequency modulation AFM has been employed. When the bias voltage is applied between the probe and the surface, the resonance frequency of the probe oscillation is shifted owing to the electrostatic force. In this paper, the basic characteristics of the electrostatic probe are investigated, experimentally. And then, the absolute distance between the probe tip and the sample surface is calculated by using the differences of the frequency shift of the probe. Finally, the measurement of surface profile is demonstrated in non-contact condition by utilizing the developed electrostatic force probe.
  • Bin Xu, Yuki Shimizu, So Ito, Wei Gao
    International Journal of Precision Engineering and Manufacturing 14 9 1535 - 1541 2013年09月 [査読有り][通常論文]
     
    A measurement system is presented for surface profile measurements of micro-structures generated on internal cylindrical surfaces of workpieces. The main components of the measurement system are an air-bearing spindle to rotate the measured internal microstructures, an air-bearing displacement sensor with a diamond micro-stylus probe to scan the surface profile of the internal microstructures being measured and a vibration isolation table to reduce the disturbance of the measurement environment. The stability of the air-bearing displacement sensor with a diamond micro-stylus probe was experimentally investigated. Measurements of surface profile of internal micro-structures were also carried out while employing a newly-developed algorithm to correct errors caused by the tip radius of the diamond micro-stylus. © 2013 Korean Society for Precision Engineering and Springer-Verlag Berlin Heidelberg.
  • Zhigang Jia, So Ito, Keiichiro Hosobuchi, Shigeaki Goto, Yuki Shimizu, Gaofa He, Wei Gao
    International Journal of Precision Engineering and Manufacturing 14 9 1543 - 1549 2013年09月 [査読有り][通常論文]
     
    This paper presents the electrostatic force characterization of a prototype scanning electrostatic force microscope (SEFM) system developed for surface profile measurement in noncontact condition. In the SEFM system, with applying a dual height method, the distance between the probe tip and the sample surface can be accurately obtained by removing the influence of the electric field distribution on the sample surface. Since the electrostatic force is greatly influenced by the capacitance between the probe tip and the sample surface, a new approach for modeling and characterization of the distribution of capacitance between the probe tip with an arbitrary shape and the sample surface with a random topography by using the finite difference method (FDM) is proposed. The electrostatic forces calculated by the FDM method and the conventional sphere-plane model are compared to verify the validity of the FDM method. The frequency shift values measured by the experiment are also compared with the simulation results calculated by the FDM method. It has been demonstrated that the electrostatic force between arbitrary shapes of the probe tip and the sample surface can be well calculated by the FDM. © 2013 Korean Society for Precision Engineering and Springer-Verlag Berlin Heidelberg.
  • Yuxin Peng, So Ito, Yasumasa Sakurai, Yuki Shimizu, Wei Gao
    International Journal of Precision Engineering and Manufacturing 14 9 1623 - 1628 2013年09月 [査読有り][通常論文]
     
    This paper presents a second-generation linear-rotary (Z-θ ) micro-stage driven by impact friction. The micro-stage was constructed by miniaturizing a previously developed linear-rotary stage. The moving element of the micro-stage, which was a steel cylinder, could be actuated along and around the Z-axis in millimeter-scale range. The steel cylinder was supported by two driving units. Each unit consisted of a permanent magnet and two piezoelectric actuators (PZTs) for generating the impact friction motions in the Z- and θ -directions. The size of the micro-stage was made to be 11.0 mm (L) × 11.0 mm (W) × 5.7 mm (H). For enhancement of the stage velocity, the transfer function of the micro-stage with the voltage applied to the PZT as the input and the PZT displacement as the output, was established. An improved waveform of the input voltage was then obtained based on the established transfer function for getting a triangular-shaped PZT displacement, which was an ideal waveform for the impact friction motion. The characteristics of the stage velocity before and after the improvement of the input voltage were verified and the effectiveness of the improved input voltage for enhancement of the stage velocity was confirmed. © 2013 Korean Society for Precision Engineering and Springer-Verlag Berlin Heidelberg. Z Z
  • Yuki Shimizu, Shigeaki Goto, Jungchul Lee, So Ito, Wei Gao, Shigeru Adachi, Kyohei Omiya, Hiroki Sato, Tetsuya Hisada, Yoshifumi Saito, Hiroaki Kubota
    Precision Engineering 37 3 640 - 649 2013年07月 [査読有り][通常論文]
     
    This paper presents an on-machine surface profile measurement system for a large mirror to be used on artificial satellites. The measurement system is constructed by mounting a long-stroke length gauge on a commercial rotary grinder for fabrications of mirror profiles. Mounting the length gauge on slides of the rotary grinder enables evaluations of the mirror profiles, which results would be used to compensate profile errors of the mirrors. In the developed system, both positioning errors and tilt misalignments of the length gauge would induce significant measurement errors. In this study, a quantitative alignment method and a compensation method are therefore developed to reduce the measurement errors related to both the positioning errors and tilt misalignments of the length gauge. In addition, a measurement uncertainty of the developed system has been systematically investigated to confirm its feasibility on the mirror profile measurements. The measured results were finally fed back to the mirror profile fabrication so that the profile error could be reduced to less than 5 μm. Mirror profiles measured on machine before and after compensation machining are also reported. © 2013 Elsevier Inc.
  • Xinghui Li, Wei Gao, Hiroshi Muto, Yuki Shimizu, So Ito, Songyi Dian
    Precision Engineering 37 3 771 - 781 2013年07月 [査読有り][通常論文]
     
    This paper presents a multi-axis surface encoder that can measure six-degree-of-freedom (six-DOF) translational displacement motions and angular motions of a planar motion stage. The six-DOF surface encoder is composed of a planar scale grating and an optical sensor head. A blue laser diode with a wavelength of 405 nm and an output power of 25 mW was employed as the light source of the sensor head. The light rays from the laser diode were collimated to a parallel beam with a diameter of 1.8 mm. The collimated beam was divided by a beam splitter into two beams, which were projected onto the scale grating and a reference grating with an identical grating period of 0.57 μm, respectively. The three-DOF translational displacement motions of the scale grating with respect to the sensor head along the X-, Y- and Z-directions were detected from the interference signals generated by superimposition of the first-order diffraction beams from the two gratings. A part of the zeroth-order and the negative first-order diffraction beams from the scale grating were employed for detection of the three-DOF angular motions about the X-, Y- and Z-axes. The sensor head was designed to have a dimension of 95 mm (X) × 90 mm (Y) × 25 mm (Z) so that it can be mounted on a previously developed planar motion stage. The grating area of the scale grating was designed to be 60 mm (X) × 60 mm (Y), which was larger than the stage moving ranges of 40 mm (X) × 40 mm (Y). Experiments were carried out to test the basic performances of the surface encoder.
  • Bin Xu, Yuki Shimizu, So Ito, Wei Gao
    Journal of the Chinese Society of Mechanical Engineers, Transactions of the Chinese Institute of Engineers, Series C/Chung-Kuo Chi Hsueh Kung Ch'eng Hsuebo Pao 34 1 73 - 80 2013年02月 [査読有り][通常論文]
     
    A micro-ball tapping probe is proposed for the form measurement of the micro-structured surface with high-aspect-ratio features. The micro-ball tapping probe is composed of a micro-ball stylus, a PZT actuator and an adapter. The micro-ball stylus consists of a micro-ball with a diameter of 50 μm, and a glass tube with a cone angle of 10 degrees. The micro-ball tapping probe was employed by a contact type air-bearing displacement sensor. Series of experiments were carried out to confirm the feasibility and performance of the proposed micro-ball tapping probe, including the strength test, the frequency characteristic test, the measurement force test and the surface form measurement for a micro-structured surface. Experimental results revealed that the micro-ball tapping probe is suitable for the form measurement of the micro-structured surface with high-aspect-ratio features.
  • Jacob W. Chesna, Yuki Shimizu, Richard K. Leach
    Proceedings of the 28th Annual Meeting of the American Society for Precision Engineering, ASPE 2013 74 - 77 2013年
  • So Ito, Sho Sekine, Yuki Shimizu, Wei Gao, Tsutomu Fukuda, Akira Kato, Kouji Kubota
    International Journal of Automation Technology 8 1 28 - 33 2013年 [査読有り][通常論文]
     
    This paper introduces the widthmeasurement of a cutting tool edge by utilizing a laser triangulation displacement sensor. By using the reflected light intensity of the laser displacement sensor, micrometric edge width which is smaller than the diameter of the laser beam spot can be measured. With regard to the quantitative evaluation of the laser spot diameter, a calibration method of the laser spot diameter is achieved by using the pin-gauges. The diameter of the laser spot is obtained by using the pin-gauges, and the relationship between the reflected light intensity and the diameter of the pin-gauges are investigated. The width of the cutting tool edge is measured by the calibrated laser spot diameter, and then the reproducibility is evaluated.
  • Wei Gao, Yuan Liu Chen, Kang Won Lee, Young Jin Noh, Yuki Shimizu, So Ito
    CIRP Annals - Manufacturing Technology 62 1 523 - 526 2013年 [査読有り][通常論文]
     
    A method is proposed for setting a new diamond cutting tool when tool replacement is required during the fabrication of a microstructure array on the outer surface of a roll by a fast tool servo with a force sensor. The sectional profiles of a small reference area in the fabricated part by the replaced old tool are detected through scanning the tip of the new tool with a constant contact force controlled by the fast tool servo. The new tool can be set accurately based on the identified position of the tool tip with respect to the reference area. © 2013 CIRP.
  • Yuki Shimizu, Yuxin Peng, Junji Kaneko, Toyohiro Azuma, So Ito, Wei Gao, Tien Fu Lu
    Sensors and Actuators, A: Physical 201 395 - 406 2013年 [査読有り][通常論文]
     
    A motion mechanism of an XY micro-stage is designed and constructed for precision positioning of light weight objects. A driving unit, which consists of two PZTs and a friction component made by permanent magnet, is mounted on the center of the stage base for driving the stage moving plate made by steel in the X- and Y-directions based on a friction drive. The moving plate is attached on the friction component by the magnetic force. Leaf springs are employed to guide the X- and Y-directional motions of the moving plate over a range of ±1 mm in both directions. The stage motion mechanism, which dominates the overall size of XY micro-stage, has a compact size of 24 mm (X) × 24 mm (Y) × 5 mm (Z). The basic performances of the stage motion mechanism have been investigated by experiments. © 2013 Elsevier B.V. All rights reserved.
  • Bin Xu, Zhigang Jia, Xinghui Li, Yuan Liu Chen, Yuki Shimizu, So Ito, Wei Gao
    Proceedings of SPIE - The International Society for Optical Engineering 8769 2013年 [査読有り][招待有り]
     
    This keynote starts from an overview of micro-optics from fundamental functions, fabrication methods and applications in precision engineering and nanotechnology. State-of-the-art measuring systems for surface form metrology of microoptics with micro-structured surfaces, including diffractive micro-optics such as diffraction gratings and refractive micro-optics such as micro lenses and micro-lens arrays, are then be presented. The measuring systems introduced in the presentation are classified into scanning probe microscope-based systems, mechanical stylus profiling systems and optical evaluation systems. Related research activities carried out in the authors' group are also highlighted. © 2013 SPIE.
  • Yuki Shimizu, Wenjian Lu, Yuta Ohba, Wei Gao
    International Journal of Automation Technology 7 6 708 - 713 2013年 [査読無し][招待有り]
     
    This paper presents an experimental study on a thermal element, which is designed to be used as a sensing device that detects a small amount of frictional heat due to a contact with nanometre-scale defects on smoothly-finished surfaces. A prototype of the thermal element, which is a thin-film resistance, is fabricated by using photolithography processes, and its sensitivity on the contact detection is investigated through some experiments, in which the thermal element is scratched by a micro-sphere controlled by PZT actuator in both X- and Z-directions so that a contact between the thermal element and defects can be simulated. Influences of an interference height and relative velocity between the thermal element and the target surface on the output of the thermal element at the contact detection are verified.
  • Zhigang Jia, Shigeaki Goto, Keiichiro Hosobuchi, So Ito, Yuki Shimizu, Wei Gao
    Proceedings of SPIE - The International Society for Optical Engineering 8759 2013年 [査読有り][通常論文]
     
    This paper presents the analysis of a prototype scanning electrostatic force microscope (SEFM) system developed for noncontact surface profile measurement. In the SEFM system, with a dual height method, the distance between the probe tip and the sample surface can be accurately obtained through removing the influence of the electric field distribution on the sample surface. Since the electrostatic force is greatly influenced by the capacitance between the probe tip and the sample surface, a new approach for modeling and analysis of the distribution of capacitance between the probe tip with an arbitrary shape and the sample surface with a random topography by using the finite difference method (FDM) is proposed. The electrostatic forces calculated by the FDM method and the conventional sphere-plane model are compared to verify the validity of the FDM method. The frequency shift values measured by experiment are also compared with the simulation results computed by the FDM method. It has been demonstrated that the electrostatic force between arbitrary shapes of the probe tip and the sample surface can be well calculated by the finite difference method. © 2013 SPIE.
  • Xinghui Li, Yuki Shimizu, So Ito, Wei Gao, Lijiang Zeng
    Proceedings of SPIE - The International Society for Optical Engineering 8759 2013年 [査読有り][通常論文]
     
    To fabricate a scale grating for a surface encoder in a cost-effective way, a blue laser diode with a wavelength of 405 nm is employed in a Lloyd's mirror interferometer to carry out interference lithography (IL) of the grating. The beams from the laser diode are collimated by an aspherical collimating lens to form beams with a diameter of 50 mm. These beams are then projected towards the Lloyd's mirror and the grating substrate, which are aligned perpendicularly with each other and are mounted on a rotary stage. One half of the beam directly goes to the grating substrate, and the other half reaches to the grating substrate after being reflected by the mirror. The direct beam and the reflected beam interference with each other to generate and expose the interference fringes, which correspond to the scale grating structures, on the substrate coated with a photoresist layer. The pitch and area of the grating structures are set to be 570 nm and around 300 mm 2, respectively. The fabricated grating structures are evaluated with an AFM to investigate the influence of the spectrum width of the laser beam. © 2013 SPIE.
  • Gaofa He, Zhigang Jia, So Ito, Yuki Shimizu, Wei Gao
    Proceedings of SPIE - The International Society for Optical Engineering 8916 2013年 [査読有り][通常論文]
     
    For measuring the surface profile of many micro-optical components which are made of non-conductive material, such as diffractive grating and Fresnel lens, with complicated shapes on their surfaces, the electrostatic force microscopy (EFM) was recommended in noncontact condition. When a bias voltage is applied between the conducting probe tip and a back electrode where a non-conducting sample was put on, an electrostatic force will be generated between the probe tip and the sample surface. The electrostatic force will change with the distance between the probe tip and the sample surface. Firstly, the relationship between the electrostatic force and the tip-sample distance was analyzed based on the dielectric polarization theory. The theoretical result shows that the electrostatic force is proportional to 1/d2, where d is the distance between the probe tip and sample surface. Then, a numerical method (finite element method -FEM) was employed to calculate the electrostatic force and the result shows accordance with the theoretical method. Finally, the prototype of a scanning electrostatic force microscopy was built which is composed of a conducting probe unit with a Z scanner driven by piezoelectric actuators, a XY scanner unit for mounting the sample and back electrode and a circuit unit for detecting the frequency shift. The force curve, which shows the relationship between the electrostatic force and the tip-sample distance, was achieved by using the EFM prototype. All results demonstrated that it is feasible for using the EFM system to measure the surface profile of non-conductor. © 2013 SPIE.
  • Akihide Kimura, Wei Gao, Woojae Kim, Koji Hosono, Yuki Shimizu, Lei Shi, Lijiang Zeng
    Precision Engineering 36 4 576 - 585 2012年10月 [査読有り][通常論文]
     
    A three-axis surface encoder was developed for stage motion measurement with sub-nanometric resolutions. The surface encoder was composed of a scale XY planar grating with X- and Y-directional periodic grating structures and an optical sensor head for reading the grating structures. A reference XY planar grating, which had the same periodic structures as those of the scale XY grating, was employed in the optical reading head. Four sets of interference signals, which were generated by superimposition of the X and Y-directional ±1 order diffracted beams from the two gratings, were employed for evaluation of the X-, Y- and Z-directional displacements of the optical sensor head with respect to the scale grating. The X- and Y-directional periodic structures of the gratings directly acted as the scale graduations for the X- and Y-directional displacement measurements, while the wavelength of the laser beam acted as the graduation period for the Z-directional displacement measurement. X- and Y-directional rectangular structures with a short period of 1 μm were designed and fabricated by the light lithography based on two beams interference for improvement of the resolutions of the surface encoder for X- and Y-directional position measurement. An optical sensor head was designed and constructed for reading the short period gratings. Experiments were carried out to confirm the basic performances of the three-axis surface encoder. © 2012 Elsevier Inc. All rights reserved.
  • Woo Jae Kim, Yuki Shimizu, Akihide Kimura, Wei Gao
    International Journal of Precision Engineering and Manufacturing 13 9 1517 - 1524 2012年09月 [査読有り][通常論文]
     
    A reflective-type linear scale with a pitch of 1.67 μm used in an interferential scanning-type 2-DOF linear encoder is evaluated by the Fizeau interferometer with a measurement range of 100 mm. The 2-DOF linear encoder produces 2-axis position signals based on the interference between the X-directional positive and negative first-order diffracted beams from the linear scale. Firstly, the Z-directional flatness e (x,y) of the linear scale is evaluated from the wavefront of the zero-order diffracted beam reflected from the linear scale. The linear scale is then tilted to align the axes of the first-order diffracted beams with that of the interferometer so that the X-directional period deviation eX(x,y)of the linear scale can be evaluated from the wavefronts of the X-directional positive and negative first--order diffracted beams. Finally, the Z-directional flatness e (x,y) and X-directional period deviation e (x,y) were verified by comparing those with the nonlinear components of the 2-DOF linear encoder using the evaluated linear scale. © KSPE and Springer 2012. Z Z X
  • Yuki Shimizu, Junguo Xu, Jianhua LI, Hidekazu Kohira, Kiyoshi Hashimoto
    Microsystem Technologies 18 9-10 1597 - 1606 2012年09月 [査読有り][通常論文]
     
    Aiming at improvements of both stability of slider flying and magnetic-recording performance under a low-clearance condition, a "narrow-grooved slider" was constructed and demonstrated at drive level. The proposed slider has narrow grooves on its center pad of an air-bearing surface for attaining a high-damping effect on pitch-mode resonant vibration of the air bearing. The relationship between the high-damping effect and the pitch-mode resonant vibration was studied, and the magnetic-recording performance at the lube/slider interaction regime was improved. In this study, first, flying-height modulation (FHM) of the slider was analyzed in the frequency domain by using a fast Fourier transform. Compared with the narrow-grooved slider, a non-grooved slider showed a larger increase in high-frequency modulation of gap flying height when the clearance was reduced to near "zero" at which the slider is starting to interact with lube. Furthermore, by means of drive-level experiments, sector error rate (SER) as a function of flying clearance was investigated. Under a low gap flying height condition, HDDs with the non-grooved slider showed slight SER degradation during slider/lube interaction. However, the narrow-grooved slider did not show any SER degradation at the same gap flying height; the damping effect of the narrow-grooved slider suppressed high-frequency FHM, thereby preventing SER degradation in the slider/lube interaction region. © Springer-Verlag 2012.
  • Shigeaki Goto, Yuki Shimizu, Jung Chul Lee, So Ito, Wei Gao, Shigeru Adachi, Kyohei Omiya, Hiroki Sato, Tetsuya Hisada, Yoshifumi Saito, Hiroaki Kubota
    Seimitsu Kogaku Kaishi/Journal of the Japan Society for Precision Engineering 78 7 631 - 635 2012年07月 [査読有り][通常論文]
     
    This paper presents an on-machine surface profile measurement system for a large mirror to be used on a satellite. The system is constructed by fixing a long-stroke length gauge on a commercial rotary grinder which fabricates the mirror. The combination of the length gauge and the grinder automatically measures the profiles which can be used in compensation of profile error. Position and attitude misalignments of the length gauge induce significant errors to the profile measurement Quantitative and efficient alignment methods are developed for the position and attitude of the length gauge. The constructed system, the developed alignment methods and profile measurement results are described.
  • Jungchul Lee, Wei Gao, Yuki Shimizu, Jooho Hwang, Jeong Seok Oh, Chun Hong Park
    International Journal of Precision Engineering and Manufacturing 13 6 861 - 867 2012年06月 [査読有り][通常論文]
     
    This paper describes a spindle error motion measurement system to evaluate the performance of the spindle of a large precision roll lathe, which is under development for fabrication of large-scale roll dies of micro-structured surfaces. The measurement system employed a large-scale roll work piece with a diameter of 320 mm and a length of 1800 mm as a measurement artifact instead of a master object to figure out the spindle error motion over the entire fabrication length. To separate the spindle error motion and the out-of-roundness of the roll work piece, the reversal method was employed. Two capacitive type displacement probes were mounted on the designed probe holders which were arranged to be faced to each other with the roll work piece between them. Spindle error motion measurement was conducted at several sections of the roll work piece along the roll axis to verify the tilt error motion of the spindle as well as the radial error motion. As the rotational speed was different for the mirror finishing fabrication of the roll work piece and fabrication of the micro-structures on the roll work piece, the spindle error motion was measured at rotational speeds of 5 and 300 rpm, respectively. Experimental results of the out-of-roundness of the roll work piece as well as the spindle error motion measurement are presented in this paper. © KSPE and Springer 2012.
  • JungChul Lee, Wei Gao, Yuki Shimizu, Jooho Hwang, Jeong Seok Oh, Chun Hong Park
    INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING 13 6 861 - 867 2012年06月 [査読有り][通常論文]
     
    This paper describes a spindle error motion measurement system to evaluate the performance of the spindle of a large precision roll lathe, which is under development for fabrication of large-scale roll dies of micro-structured surfaces. The measurement system employed a large-scale roll workpiece with a diameter of 320 mm and a length of 1800 mm as a measurement artifact instead of a master object to figure out the spindle error motion over the entire fabrication length. To separate the spindle error motion and the out-of-roundness of the roll workpiece, the reversal method was employed. Two capacitive type displacement probes were mounted on the designed probe holders which were arranged to be faced to each other with the roll workpiece between them. Spindle error motion measurement was conducted at several sections of the roll workpiece along the roll axis to verify the tilt error motion of the spindle as well as the radial error motion. As the rotational speed was different for the mirror finishing fabrication of the roll workpiece and fabrication of the micro-structures on the roll workpiece, the spindle error motion was measured at rotational speeds of 5 and 300 rpm, respectively. Experimental results of the out-of-roundness of the roll workpiece as well as the spindle error motion measurement are presented in this paper.
  • Jung Chul Lee, Wei Gao, Yuki Shimizu, Jooho Hwang, Jeong Seok Oh, Chun Hong Park
    Precision Engineering 36 2 244 - 251 2012年04月 [査読有り][通常論文]
     
    This paper presents the measurement of carriage slide motion error of a drum roll lathe. The slide motion error, which is composed of the out-of-straightness error component and the axis misalignment error component between the axis of motion of the carriage slide and the axis of rotation of the spindle, is measured by using two capacitive probes placed on the two sides of a roll workpiece. The capacitive probes are first moved by the carriage slide to scan the stationary roll workpiece from the starting position to the end position of the carriage slide travel range before and after a 180° rotation of the workpiece about the axis of rotation of the spindle. The out-of-straightness motion error component of the carriage slide can be accurately evaluated by separating the influence of the workpiece out-of-straightness form error component based on the reversal method. The two capacitive probes are then kept stationary at the start position and the end position of the carriage slide travel range, respectively, to scan the rotating roll workpiece over multiple rotations. The axis misalignment error component can be evaluated from an averaging operation of the probe outputs of the capacitive probes over one rotation or multiple rotations, which removes the influence of the workpiece out-of-roundness form error component as well as the spindle motion error. Experiments were carried out on a drum roll lathe over a carriage slide travel range of 1700 mm. © 2011 Elsevier Inc. All rights reserved.
  • Kang Won Lee, So Ito, Yuki Shimizu, Wei Gao, Katsutoshi Tanaka, Masahiko Fukuta, Yoshiaki Kai
    2012 IEEE I2MTC - International Instrumentation and Measurement Technology Conference, Proceedings 2469 - 2471 2012年 [査読有り][通常論文]
     
    This paper presents the experimental investigations for performance evaluation of an air-bearing displacement sensor as a measurement system for nanometrology of surface forms by using it. The experimental configuration and some considerations for the air-bearing displacement sensor are described. Then, in order to identify the basic performance of the sensor, a measuring force and displacement output of the sensor are evaluated on a vibration isolated table. The sensor is also mounted on a diamond turning machine to evaluate the surface form of micro structures. A roll workpiece with Ni-P plating surface, on which micro-lens array are fabricated by using a FS-FTS (Force sensor fast tool servo) on the machine tool, is employed as a specimen for measurement. © 2012 IEEE.
  • Yuki Shimizu, Sungho Jang, Takemi Asai, So Ito, Wei Gao
    2012 IEEE I2MTC - International Instrumentation and Measurement Technology Conference, Proceedings 2395 - 2397 2012年 [査読有り][通常論文]
     
    In this paper, a scanning-light method is proposed to evaluate the form of the tool cutting edge in a wide range up to several millimeters. An optical system, which consists of a photo diode, a laser diode unit and an objective lens, was developed. A small laser spot generated by the objective lens scans across the tool cutting edge, while monitoring the intensity of the laser beam passed through the tool cutting edge. In the proposed method, variation of the detected intensity is converted into information of the measured tool form. Feasibility of the proposed method was confirmed by simulations and experiments. © 2012 IEEE.
  • Wenjian Lu, Yuki Shimizu, So Ito, Wei Gao
    Key Engineering Materials 523-524 826 - 831 2012年 [査読有り][通常論文]
     
    A design study of a thermal-type contact sensor for the detection of small defects, the heights of which are less than 16 nm on wafer surfaces, is described in this paper. The feasibility of the contact sensor, which would detect frictional heat generated at the contact with defects, was theoretically investigated focusing on the temperature rise of the sensor element. To investigate the temperature rise of the contact sensor due to the generated frictional heat, both the theoretical calculation with a simple model of heat transfer and a simulation with a finite element model (FEM) were carried out. Relationship between the sensor size and the response of the temperature rise of the contact sensor was also investigated by using FEM simulation. © (2012) Trans Tech Publications, Switzerland.
  • Sung Ho Jang, Yuki Shimizu, Takemi Asai, So Ito, Wei Gao
    Key Engineering Materials 523-524 925 - 931 2012年 [査読有り][通常論文]
     
    This paper presents an optical probe employed for edge contour measurement of single point diamond cutting tools. A laser beam from a laser diode (LD) is focused by an objective lens to form a small light spot with a radius of approximately 20 μm, and is then received by a photodiode (PD) after passed through a focal point of the objective lens. A cutting edge of the tool, which is placed on a line with the LD and the PD, is inserted into the laser beam section. At an each X-position, the output of the PD is recorded while the light spot is moved along the Z-direction, scanning across the cutting edge of the tool with its rake face aligned in the XZ plane. The Z-position of the cutting edge is evaluated by determining a specific value from the obtained outputs of the PD. The edge contour of the diamond cutting tool can thus be measured by repeating the Z-scanning at different X-positions. Computer simulation was carried out to investigate the influences of error factors on the evaluation of the cutting edge. Experiments were also carried out to measure a round nose of the tool with a nominal nose radius of 2 mm. © (2012) Trans Tech Publications, Switzerland.
  • Toyohiro Azuma, Eiji Niwa, Yuxin Peng, Junji Kaneko, Yuki Shimizu, So Ito, Wei Gao
    Key Engineering Materials 523-524 939 - 944 2012年 [査読有り][通常論文]
     
    A strain-gauge-type precision displacement sensor, which is developed for the positioning of a micro-XY stage, is described in this paper. A thin-film strain-gauge element, which is made of Cr-N alloy, is directly fabricated on a ceramic base plate by using photolithography processes to achieve higher sensitivity and better thermal stability for the detection of the stage displacement. In this study, several designs of the thin-film strain gauge including both two-gauge type and four-gauge type are fabricated to investigate sensor performances such as sensitivity, stability and so on. Details of the design, fabrication and evaluation results of the Cr-N strain-gauge-type displacement sensor are described. © (2012) Trans Tech Publications, Switzerland.
  • So Ito, Kang Won Lee, Yuki Shimizu, Wei Gao
    Key Engineering Materials 523-524 945 - 950 2012年 [査読有り][通常論文]
     
    A contact stylus-type displacement sensor is proposed for a surface form measurement of micro-structures. The stylus is supported by an air-bearing, thus it can be moved smoothly without friction between the stylus and the air-bearing. In order to reduce the measurement force, a novel controlling technique of a contact force has been developed. During the measurement one edge of the stylus is maintained contact with the measured surface by its own weight. Another end of the stylus is connected with a counter weight by a string and the stylus is hanging on the string in order to reduce the contact force between the edge of the stylus and the measured surface. Measuring force is estimated to confirm the effectiveness of the counter weight. Surface measurement of a steel ball is carried out using the developed air-bearing displacement sensor. © (2012) Trans Tech Publications, Switzerland.
  • Shinichi Osawa, So Ito, Yuki Shimizu, Sungho Jang, Wei Gao, Tsutomu Fukuda, Akira Kato, Kouji Kubota
    Journal of Advanced Mechanical Design, Systems and Manufacturing 6 6 815 - 828 2012年 [査読有り][通常論文]
     
    This paper proposed a high speed and a high accuracy measurement method for the cutting edge height of a rotary cutting tool with respect to the reference surface on the tool by using a laser triangulation displacement sensor. In the measurement, not only the displacement output but also the light intensity output of the laser displacement sensor, which corresponds to the intensities of the laser beam reflected from the cutting tool surface, are acquired when the laser displacement sensor scans across the cutting edge. To remove the influence of the width of the cutting edge, the cutting edge height is determined from the sensor displacement output when the sensor light intensity output reaches to the maximum. It has been confirmed by theoretical analysis, computer simulation and experiment that the proposed method is effective even when the width of the cutting edge is smaller than the diameter of the laser spot of the sensor. © 2012 by JSME.
  • Bin Xu, Yuki Shimizu, Toshiki Takeishi, So Ito, Wei Gao
    Journal of Advanced Mechanical Design, Systems and Manufacturing 6 6 936 - 948 2012年 [査読有り][通常論文]
     
    A measurement system is presented for the surface form measurement of a cylindrical workpiece with periodic microstructures generated on the outer surface of the workpiece. The main components of the measurement system are a spindle to rotate the workpiece, and an air-bearing displacement sensor with a diamond micro stylus to detect the surface form of the workpiece. The surface form of the micro-structured workpiece was measured in different rotation speeds and the relationship between the measurement repeatability and the rotation speed was investigated. The Fourier transform analysis and the wavelet transform analysis were employed to analyze the measurement results in the time-frequency domain for the identification of the error sources with specific frequency characteristics. © 2012 by JSME.
  • 後藤成晶, 清水裕樹, LEE JungChul, 伊東聡, GAO Wei, 足立茂, 大宮恭平, 佐藤広規, 久田哲弥, 齋藤佳史, 久保田浩明
    精密工学会誌 78 7 2012年 [査読有り][通常論文]
  • Shimizu Yuki, Xu Bin, Gao Wei
    International Journal of Nanomanufacturing 8 1-2 87 - 105 2012年01月 [査読有り][通常論文]
     
    Two types of micro-ball styluses were fabricated for scanning-type surface form metrology. The micro-ball stylus is composed of a precision glass micro-ball and a shaft made by stainless steel or glass tube. The diameter of the micro-ball was less than 50 μm. The tip angle of the glass-tube shaft was approximately 10 degrees and that of the stainless steel shaft was approximately 50 degrees. It was confirmed that the micro-ball stylus with the glass-tube shaft can tolerate a 90 mN external force applied from the direction with an angle of 45 degrees with respect to the shaft axis, which was much more tolerant than the micro-ball stylus with the stainless steel shaft. To reduce the influence of the stick-slip phenomena caused by friction between the ball and the scanned surface, a PZT actuator was added to the micro-ball stylus, which is called the micro-tapping probe, so that the ball can be oscillated with a high frequency. Experiments of scanning the micro-ball stylus, which was mounted on an air-bearing displacement sensor, over a flat surface were carried out to test some basic performances of the micro-ball stylus. © 2012 Inderscience Enterprises Ltd.
  • Sung Ho Jang, Takemi Asai, Yuki Shimizu, Wei Gao
    International Journal of Nanomanufacturing 8 1-2 106 - 122 2012年01月 [査読有り][通常論文]
     
    This paper presents a measuring station based on an atomic force microscope (AFM), which is designed and constructed on a four-axis diamond turning machine for inspection of the cutting edge profile of single point diamond micro-tools. The measuring station is composed of an AFM probe unit for three-dimensional (3D) edge profile measurement and an alignment system with an optical sensor for aligning the probe-tip with the edge top of the tool chip. The alignment system greatly shortens the alignment time, which is essential for carrying out the edge profile measurement by the AFM. Measurement experiments of round nose micro-tools with nominal nose radii of 8 μm and less than 2 μm were carried out to demonstrate the performance of the measuring station. © 2012 Inderscience Enterprises Ltd.
  • Wenjian Lu, Shimizu Yuki, Gao Wei
    Advanced Materials Research 497 137 - 141 2012年 [査読有り][通常論文]
     
    A thermal-type contact sensor was proposed to detect small defects, the heights of which are less than 16 nm, on the wafer surface. The feasibility of the contact sensor, which detects frictional heat generated at the contact, was theoretically investigated focusing on the temperature rise of the sensor element. Simulation results with both the simple model of heat transfer and the FEM model showed that the expected temperature rise of the contact sensor is enough to be detected by the conventional electric circuit. © (2012) Trans Tech Publications.
  • Wei Gao, Shigeaki Goto, Keiichiro Hosobuchi, So Ito, Yuki Shimizu
    CIRP Annals - Manufacturing Technology 61 1 471 - 474 2012年 [査読有り][通常論文]
     
    A scanning electrostatic force microscope is presented for noncontact surface profile measurement. A charged conducting probe tip is oscillated by a tuning fork quartz crystal resonator. The probe tip is scanned over the sample surface by using an XY scanner in such a way that the frequency shift of the tuning fork oscillation, which corresponds to the electrostatic force gradient, is kept constant by controlling the probe Z position with a Z scanner. A dual height method is proposed to accurately obtain the tip to sample distances through removing the influence of the electric field distribution on the sample surface. © 2012 CIRP.
  • Yuxin Peng, So Ito, Yuki Shimizu, Wei Gao
    Key Engineering Materials 523-524 650 - 655 2012年 [査読有り][通常論文]
     
    In this paper, a novel Z-θ micro-stage is designed and constructed by utilizing a smooth impact friction drive. The stage is configured by two driving units, a moving element and a base. Each driving unit consists of two PZTs and a friction element. One end of each PZT is fixed on the base of the stage, and the other end is attached on a permanent magnet as the friction element. The moving element, which is a steel cylinder, is supported and moved by the friction element. Magnetic force generated by permanent magnet is utilized to stabilize the driving condition between the moving element and the friction element for friction drive. The size of the stage is less than 1 cm . The stroke and the maximum speed of the stage in Z-direction are 3.8 mm, 5.7 mm/s, respectively. The stroke in θ -direction is unlimited and the maximum rotational velocity is 26 rpm. © (2012) Trans Tech Publications, Switzerland. Z Z 3
  • Wenjian Lu, Yuki Shimizu, So Ito, Wei Gao
    EMERGING TECHNOLOGY IN PRECISION ENGINEERING XIV 523-524 826 - 831 2012年 [査読有り][通常論文]
     
    A design study of a thermal-type contact sensor for the detection of small defects, the heights of which are less than 16 nm on wafer surfaces, is described in this paper. The feasibility of the contact sensor, which would detect frictional heat generated at the contact with defects, was theoretically investigated focusing on the temperature rise of the sensor element. To investigate the temperature rise of the contact sensor due to the generated frictional heat, both the theoretical calculation with a simple model of heat transfer and a simulation with a finite element model (FEM) were carried out. Relationship between the sensor size and the response of the temperature rise of the contact sensor was also investigated by using FEM simulation.
  • Kang Won Lee, So Ito, Yuki Shimizu, Wei Gao, Katsutoshi Tanaka, Masahiko Fukuta, Yoshiaki Kai
    Key Engineering Materials 523-524 836 - 841 2012年 [査読有り][通常論文]
     
    This paper presents the dynamic response of an air-bearing displacement sensor for on-machine surface form measurement of micro structures. The on-machine measurement system has some merits in terms of measurement efficiency and re-machining for error compensation after measurement. On the other hand, the performance of the contact type measurement system based on stylus methods is dominated by the dynamic characteristics of the system because the system is subject to random vibrations of the machine tool including the spindle during measurement. Therefore, the dynamic response of the system is useful for analyzing the mechanical vibrations of the practical on-machine measurement system. In this paper, the equation of motion for the air-bearing displacement sensor to the excited input displacement is derived and the displacement behavior of the system by using a PZT actuator is investigated within certain frequency ranges experimentally for identifying the dynamics of the system. © (2012) Trans Tech Publications, Switzerland.
  • Jung Chul Lee, Wei Gao, Yuki Shimizu, So Ito, Jooho Hwang, Jeong Seok Oh, Chun Hong Park
    Key Engineering Materials 523-524 847 - 852 2012年 [査読有り][通常論文]
     
    This paper describes the analysis and measurement of the dynamic motions of a large-scale rotating roll workpiece, which is used for a large-scale lathe, under the gravity condition. A dynamic model which includes the gravity effect was first established. In order to investigate the behavior which comes from stiffness differences of the journal bearing at the headstock and the tailstock, a spring-mass-damper system was also established. In addition to the simulations, the behavior of the rotating roll workpiece was investigated with respect to the different rotating speed. In the experiment, a mirror finished hollow type roll workpiece with a diameter of 320 mm, a length of 1800 mm, a weight of about 340 kg was fabricated by a large-scale lathe. Five capacitive type displacement sensors were mounted on the sensor holders which were arranged along the axis of rotation of the spindle. The behavior measurement was carried out at 5 sections of the roll workpiece along the axial direction. The rotating speed was set to be 5, 50, 100, 150, 200, 250 and 300 rpm. The dynamic model for the analysis with simulations and the measurement result of the behavior of a rotating roll workpiece according to the different rotating speed are presented in this paper.
  • Bin Xu, So Ito, Yuki Shimizu, Wei Gao
    Key Engineering Materials 523-524 853 - 858 2012年 [査読有り][通常論文]
     
    An eccentric error compensation method is presented for the pitch deviation measurement of gears. The eccentric error compensation method mainly consists of the evaluation of the assembly accuracy, the reconstruction of the reference curve and the coordinate compensation of intersection points. The geometrical model of the measurement system was analyzed and the corresponding mathematical model was proposed. A gear with small modulus was adopted as the specimen for the pitch deviation measurement. Experimental results reveal that the values of eccentricity can be extracted from the measured profile successfully and the eccentric error compensation is effective for the pitch deviation measurement of gears. © (2012) Trans Tech Publications, Switzerland.
  • Yuki Shimizu, Woo Jae Kim, So Ito, Wei Gao
    Key Engineering Materials 523-524 859 - 864 2012年 [査読有り][通常論文]
     
    A form error characterization of a reflective-type scale grating, which is used in three-degree-of-freedom (3-DOF) encoders for position measurement of a planar motion stage, is presented. The scale grating has a micro-structured surface, the pitch of which is 1 μm in both Xand Y- direction. The periodic pattern on the scale grating generates diffracted beams when a laser beam incidents to the grating surface. The ±1st order diffracted beams from the grating contain information about the stage motions of not only X- or Y- directional in-plane displacement but also Z-directional out-of-plane displacement, and are therefore able to be utilized for multi-axis position detection. Accuracies of the position detection are mainly determined by a period deviation and a Z-directional out-of-flatness of the scale grating. The form error characterization of the grating is possible by using Fizeau interferometer, although the form error of a reference mirror in the Fizeau interferometer still remains as a measurement error in the form of the measured scale grating. In this paper, a new method was proposed to evaluate the form error characterization of the scale grating for the 3-DOF encoder, while eliminating the form error of the reference mirror in the Fizeau interferometer. © (2012) Trans Tech Publications, Switzerland.
  • Xinghui Li, Yuki Shimizu, Hiroshi Muto, So Ito, Wei Gao
    Key Engineering Materials 523-524 913 - 918 2012年 [査読有り][通常論文]
     
    A compact optical three-axis surface encoder, which can detect displacements in the XYZ-directions simultaneously by employing a scale grating with a short pitch (0.57 μm) and a single laser beam with a short wavelength (405 nm), is described in this paper. This surface encoder mainly consists of a blue-ray laser diode, a pair of two-dimensional diffractive gratings serving as scale grating and reference grating, respectively, and two quarter photodiodes (QPD) utilized for detecting output optical density. The displacements of the scale grating along X-, Y- and Z-directions are measured by analyzing interference signals caused by the phase shifts and light path difference of diffracted beams from the scale grating and reference grating. Basic measurement principle is illuminated, a compact surface encoder is designed and evaluation experiments are carried out. © (2012) Trans Tech Publications, Switzerland.
  • Woo Jae Kim, Yuki Shimizu, Koji Hosono, Ito So, Wei Gao
    Key Engineering Materials 523-524 919 - 924 2012年 [査読有り][通常論文]
     
    A three-axis mosaic surface encoder, which can measure the X-directional position and the Y-, Z-directional straightness of the linear stage in a long range, is proposed. The three-axis mosaic surface encoder is composed of multiple scanning probes and a mosaic scale grating. The mosaic scale grating is constructed by placing the multiple two-dimensional reflective-type scale gratings in a line to obtain long measurement range along the in-plane direction of a scale grating. In addition, the optical configuration of the encoder head, which employs multiple scanning probes to be projected on the mosaic scale grating, is proposed so that a long range measurement can be achieved by the mosaic scale gratings. With the proposed encoder head, the measurement information of the X-directional displacement can always be obtained from the probe which is not on the gaps of the mosaic scale grating. The proposed configuration was applied to the three-axis surface encoder, and basic performances of the proposed three-axis mosaic surface encoder are experimentally investigated. © (2012) Trans Tech Publications, Switzerland.
  • SungHo Jang, Yuki Shimizu, Takemi Asai, So Ito, Wei Gao
    EMERGING TECHNOLOGY IN PRECISION ENGINEERING XIV 523-524 925 - 931 2012年 [査読有り][通常論文]
     
    This paper presents an optical probe employed for edge contour measurement of single point diamond cutting tools. A laser beam from a laser diode (LD) is focused by an objective lens to form a small light spot with a radius of approximately 20 mu m, and is then received by a photodiode (PD) after passed through a focal point of the objective lens. A cutting edge of the tool, which is placed on a line with the LD and the PD, is inserted into the laser beam section. At an each X-position, the output of the PD is recorded while the light spot is moved along the Z-direction, scanning across the cutting edge of the tool with its rake face aligned in the XZ plane. The Z-position of the cutting edge is evaluated by determining a specific value from the obtained outputs of the PD. The edge contour of the diamond cutting tool can thus be measured by repeating the Z-scanning at different X-positions. Computer simulation was carried out to investigate the influences of error factors on the evaluation of the cutting edge. Experiments were also carried out to measure a round nose of the tool with a nominal nose radius of 2 mm.
  • Toyohiro Azuma, Eiji Niwa, Yuxin Peng, Junji Kaneko, Yuki Shimizu, So Ito, Wei Gao
    EMERGING TECHNOLOGY IN PRECISION ENGINEERING XIV 523-524 939 - + 2012年 [査読有り][通常論文]
     
    A strain-gauge-type precision displacement sensor, which is developed for the positioning of a micro-XY stage, is described in this paper. A thin-film strain-gauge element, which is made of Cr-N alloy, is directly fabricated on a ceramic base plate by using photolithography processes to achieve higher sensitivity and better thermal stability for the detection of the stage displacement. In this study, several designs of the thin-film strain gauge including both two-gauge type and four-gauge type are fabricated to investigate sensor performances such as sensitivity, stability and so on. Details of the design, fabrication and evaluation results of the Cr-N strain-gauge-type displacement sensor are described.
  • So Ito, Kang-Won Lee, Yuki Shimizu, Wei Gao
    EMERGING TECHNOLOGY IN PRECISION ENGINEERING XIV 523-524 945 - 950 2012年 [査読有り][通常論文]
     
    A contact stylus-type displacement sensor is proposed for a surface form measurement of micro-structures. The stylus is supported by an air-bearing, thus it can be moved smoothly without friction between the stylus and the air-bearing. In order to reduce the measurement force, a novel controlling technique of a contact force has been developed. During the measurement one edge of the stylus is maintained contact with the measured surface by its own weight. Another end of the stylus is connected with a counter weight by a string and the stylus is hanging on the string in order to reduce the contact force between the edge of the stylus and the measured surface. Measuring force is estimated to confirm the effectiveness of the counter weight. Surface measurement of a steel ball is carried out using the developed air-bearing displacement sensor.
  • J. Xu, Y. Shimizu, J. Liu, T. Shiramatsu, M. Furukawa, J. Li, H. Kohira
    2012 Digest APMRC - Asia-Pacific Magnetic Recording Conference: A Strong Tradition. An Exciting New Look! 49 6 2715 - 2718 2012年 [査読有り][通常論文]
     
    Pit detection study of a thermal contact sensor was carried out by both experiments and simulation. The experimental results showed that the thermal contact sensor was able to detect a small pit with good sensitivity. And the simulation study revealed that the mechanism of pit detection is due to worse cooling, which results in higher sensor temperature, because the sensor/disk spacing is larger on the pit. The maximum temperature increase is significant initially with increasing pit depth but saturates when the depth is larger than 60 nm. © 2012 DSI.
  • Woo Jae Kim, Akihide Kimura, Koji Hosono, Yuki Shimizu, Wei Gao
    International Journal of Nanomanufacturing 7 5-6 409 - 426 2011年11月 [査読有り][通常論文]
     
    This paper describes an overview of the multi-axis grating encoders developed for measurement of stage motions. Two grating mirrors are employed in the grating encoders. One of the grating mirrors is utilised as the scale grating. The other grating mirror is included in the sensor head as the reference grating. The ±1st order diffracted beams from the two grating mirrors are superimposed to generate interference signals, which have information about not only the Z-directional out-of-plane displacement but also X- or Y-directional in-plane displacement. A prototype two-axis linear grating encoder with a software compensation technique for X- and Z-directional measurement, and a prototype three-axis surface grating encoder with a double Y-PD unit design for X-, Y- and Z-directional measurement are then presented. © 2011 Inderscience Enterprises Ltd.
  • Sung Ho Jang, Takemi Asai, Yuki Shimizu, Wei Gao
    International Journal of Automation Technology 5 6 862 - 865 2011年11月 [査読有り][通常論文]
     
    In this paper, the relationship between the photodetector outputs and the three-dimensional (3D) positioning of a micro-object in an optical probe is first analyzed based on geometric optics. In the optical model established for the analysis, a collimated laser beam is focused by an objective lens to generate a small beam spot at the focal position and a thin and rectangular micro-object is set close to the focal position. The influence of diffraction of the laser beam is investigated based on a model based on wave optics.
  • Yuki Shimizu, Junguo Xu, Hidekazu Kohira, Masayuki Kurita, Toshiya Shiramatsu, Masaru Furukawa
    IEEE Transactions on Magnetics 47 10 3426 - 3432 2011年10月 [査読有り][招待有り]
     
    Targeting both higher touchdown sensitivity and highly accurate nanometer-scale defect detection on a disk surface, a thermal-contact sensor, integrated into a magnetic-head slider, was developed. It was experimentally shown that the contact sensor has sensitivity for detecting head-disk contact at each radial position on a disk surface equivalent to that of a conventional acoustic-emission (AE) sensor. It was also shown that a defect-detection method using the thermal-contact sensor is feasible. Defect mapping, in which a slider inspecting the disk at a certain clearance detects small defects on the disk surface, done with this method was better sensitive with measurements with an optical surface analyzer (OSA). Defect mapping on a proto-type glide tester, based on a conventional glide tester, using the thermal-contact sensor was also demonstrated. © 2011 IEEE.
  • Kang Won Lee, Young Jin Noh, Wei Gao, Yoshikazu Arai, Yuki Shimizu, Katsutoshi Tanaka, Masahiko Fukuta, Yoshiaki Kai
    International Journal of Precision Engineering and Manufacturing 12 4 671 - 678 2011年08月 [査読有り][通常論文]
     
    This paper presents the experimental results of investigating the performances of an air-bearing displacement sensor for surface form measurement of micro-structures, such as micro-lenses, on an ultra-precision machine tool. The sensor consists of a stylus for contacting the surface, a shaft for mounting the stylus, an air-bearing for suspending the shaft and a blade spring for applying the measuring force against the surface. At first, experiments were conducted on a vibration isolated table to identify the basic performance of the sensor for displacement measurement. Then, the sensor was mounted on a diamond turning machine for evaluating the performance of the sensor for on-machine surface form measurement of micro-lenses. A roll workpiece, on which a micro-lens array was fabricated by using a fast tool servo on the diamond turning machine, was employed as the specimen for the on-machine experiment of surface profile measurement. © KSPE and Springer 2011.
  • Kang-Won Lee, Young-Jin Noh, Wei Gao, Yoshikazu Arai, Yuki Shimizu, Katsutoshi Tanaka, Masahiko Fukuta, Yoshiaki Kai
    INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING 12 4 671 - 678 2011年08月 [査読有り][通常論文]
     
    This paper presents the experimental results of investigating the performances of an air-bearing displacement sensor for surface form measurement of micro-structures, such as micro-lenses, on an ultra-precision machine tool. The sensor consists of a stylus for contacting the surface, a shaft for mounting the stylus, an air-bearing for suspending the shaft and a blade spring for applying the measuring force against the surface. At first experiments were conducted on a vibration isolated table to identify the basic performance of the sensor for displacement measurement. Then, the sensor was mounted on a diamond turning machine for evaluating the performance of the sensor for on-machine surface form measurement of micro-lenses. A roll workpiece, on which a micro-lens array was fabricated by using a fast tool servo on the diamond turning machine, was employed as the specimen for the on-machine experiment of surface profile measurement.
  • Yuki Shimizu, Junguo Xu, Hidekazu Kohira, Kenji Kuroki, Kyosuke Ono
    Microsystem Technologies 17 5-7 897 - 902 2011年06月 [査読有り][通常論文]
     
    To investigate the possibility of further lowering the clearance in head-disk interface systems, slider dynamic behavior during a touchdown sequence with a thermal flying-height control (TFC) function was investigated by using a spinstand-level evaluation utilizing an acoustic emission (AE) sensor and a laser Doppler vibrometer (LDV). Experimental results demonstrated that off-track vibration was easier to excite by head-disk contact at the beginning of head-disk contact. We then confirmed that the amplitude of pitch-mode vibration in the flying-height direction increased and sway-mode vibration in the off-track direction decreased when increasing heater power during the touchdown sequence. Moreover, we found that the peak frequency of pitch-mode vibration shifted to a higher frequency under over-push conditions. Time-frequency domain analysis results showed that the peak shift occurred at several locations during a disk rotation. The mechanism of the peak shift is attributed to the increase in stiffness at the head-disk interface (HDI) due to solid-solid contact or mode change occurred in such regions. During the touchdown sequence, the friction force at the HDI continues to increase, even though slider vibration and AE signal decrease when heater power is increased. The friction force at the HDI needs to be decreased to achieve further low-clearance HDI. © 2011 Springer-Verlag.
  • Akihide Kimura, Koji Hosono, Woo Jae Kim, Yuki Shimizu, Wei Gao, Lijiang Zeng
    International Journal of Nanomanufacturing 7 1 73 - 91 2011年05月 [査読有り][通常論文]
     
    A new optical two-degree-of-freedom (2-DOF) linear encoder with a mosaic scale grating is proposed to expand the measurement range along the in-plane direction of the grating. The 2-DOF linear encoder has the ability to measure the in-plane displacement along the axis of the scale grating (X-axis) and the out-of-plane displacement perpendicular to the scale grating plane (Z-axis). The measurement range of the optical linear encoder along the X-axis, which is determined by the length of the scale grating, is expanded by using a mosaic scale grating with multiple scale gratings aligned along the X-axis. A new optical configuration of the sensor head, which projecting multiple light probes onto the mosaic scale grating, is presented. The 2-DOF displacements can be obtained accurately from the probe which is not on the gaps between scale gratings. The feasibility of the 2-DOF linear encoder with the multi-probe configuration has been verified by experimental results. The X-and Z-directional resolutions were about 5 nm and 1 nm, respectively. The peak to valley amplitude of the non-linear component was within ±50 nm in the measurement error of the X-directional sensor output, which was obtained by the stitching outputs from the multiple light probes. © 2011 Inderscience Enterprises Ltd.
  • Yu Xin Peng, Wei Gao, Jun Kaneko, Yoshikazu Arai, Yuki Shimizu, Koichi Okamoto, Miho Chiba, Shuji Aisawa
    Nami Jishu yu Jingmi Gongcheng/Nanotechnology and Precision Engineering 9 3 221 - 227 2011年05月 [査読有り][通常論文]
     
    In this paper, a linear micro-stage with a long stroke was presented based on the principle of impact friction drive for precision positioning of micro-objects. By employing small and strong magnets as friction elements, the influence of changes in frictional force due to wear of friction elements can be reduced, which improves the stability of the stage. A prototype stage was designed and constructed, and experiments were carried out to test the basic performance of the stage. It has been verified that, with a compact size of 20 mm × 10 mm × 3 mm, the stage can achieve a resolution of 6 nm, a maximum driving speed of 5.4 mm/s, and a total displacement of 20 mm.
  • Koji Hosono, Woo Jae Kim, Akihide Kimura, Yuki Shimizu, Wei Gao
    International Journal of Automation Technology 5 2 91 - 96 2011年03月 [査読有り][通常論文]
     
    The surface encoder we propose for simultaneously measuring XYZ-directional displacements consists of a XY-axis with a scale grating and an optical sensor head. The XY-axis scale grating size determines the surface encoder's measurement range in plane - in the X and Y directions. The mosaic XY-axis scale grating we use to expand the measurement range in plane consists of multiple XY-axis scale gratings arranged in plane. We present two optical configurations for the mosaic XY-axis scale grating. To confirm our configurations' effectiveness, we fabricated two prototypes that we tested in basic experiments using a mosaic single-axis scale grating.
  • 李 貞徹, 清水 裕樹, 高 偉, Park ChunHong, Hwang Jooho, Oh JeongSeok
    精密工学会学術講演会講演論文集 2011 876 - 877 公益社団法人 精密工学会 2011年 
    This paper presents a spindle error measurement system to evaluate the performance of a spindle of a large-scale ultra-precision lathe, which is under development for fabrication of large roll dies with micro-structured surfaces. Measurement of the spindle error motion is an important issue for the ultra-precision lathe because the fabrication accuracy is influenced by the motion error. In order to measure the spindle error motion of the large-scale ultra-precision lathe, reversal technique is employed. In this research, large-scale roll workpiece is used as the measurement artifact instead of other master ball or cylinders. This paper reports the spindle error motion measurement with refined reversal operation method for the reversal of the large-scale roll workpiece. Spindle error motion was evaluated over the entire fabrication length (1.7 m) of the large-scale ultra-precision lathe.
  • Shinichi Osawa, Yuki Shimizu, Wei Gao, Tsutomu Fukuda, Akira Kato, Kouji Kubota
    Proceedings of the 6th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2011 2011年 
    This paper presents a high speed and a high accurate measurement method for the height of the cutting edge of a rotary cutting tool with respect to the reference surface on the tool by using a laser displacement sensor. In this method, the height of the cutting edge is obtained from the output of the optical displacement sensor when the intensity output reaches the maximum. Both simulation and experimental results confirmed that the proposed method enables us to measure the height of cutting edge, the width of which is smaller than that of the laser spot.
  • Toshiki Takeishi, Xu Bin, Yuki Shimizu, Wei Gao
    Proceedings of the 6th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2011 2011年 
    This paper presents precision measurement of a micro-part which has micro-structured surfaces. Micro-parts sometimes have short pitches and large amplitudes. Measurements are conducted by the use of conventional measuring instruments and found that these instruments are difficult to measure their profiles. A novel measuring system is presented which uses a contact-type displacement sensor, probe shaft of which is levitated by air-bearings to reduce the contact force. After developing the new measuring system, measurement and analysis results are shown. Wavelet analysis reveals that there are errors in the measurement results and they are caused by stylus jump.
  • Takayuki Meguro, Yuki Shimizu, Wei Gao
    Proceedings of the 6th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2011 2011年 
    This research describes an angle sensor based on laser autocollimation, with a laser rangefinder which is based on the principle of phase-difference distance measurement using a pulsed light source. The angle sensor and the laser rangefinder are combined with each other by sharing the same laser source for simultaneous measurement of the moving distance and two-axis tilt angles of a target mirror. A prototype sensor was fabricated and the evaluation experiment was conducted. Experimental results have shown that the sensor has a resolution of 1 mm for distance measurement and a resolution of 0.1 arc-seconds for tilt angle measurements.
  • AN OVERVIEW OF PRECISION MEASUREMENT TECHNOLOGY IN HEAD-DISK INTERFACE IN HARD DISK DRIVES
    Yuki Shimizu
    Proceedings of The 7th International Symposium on Precision 2011年 [査読無し][招待有り]
  • W. Gao, Y. Saito, H. Muto, Y. Arai, Y. Shimizu
    CIRP Annals - Manufacturing Technology 60 1 515 - 518 2011年 [査読有り][通常論文]
     
    This paper presents a new autocollimator that can simultaneously detect the three-axis angular error motions (pitch, yaw, and roll errors) of a precision linear stage. A collimated laser beam from a laser diode is projected onto a grating reflector mounted on the stage. The reflected 0th-order diffracted beam is received by an autocollimation unit, which consists of a collimator objective and a quadrant photodiode, for detecting the pitch and yaw errors. The reflected 1st-order diffracted beam is received by another autocollimation unit for detecting the roll error. Experiments were carried out to evaluate the basic performance of the prototype sensor. © 2011 CIRP.
  • Precision measurement of micro-lens profile by using a force-controlled diamond cutting tool on an ultra-precision lathe
    K. W. Lee, Y. J. Noh, Y. Arai, Y. Shimizu, W. Gao
    International Journal of Precision Technology 2011年 [査読有り][通常論文]
  • Y. Shimizu, S. Osawa, T. Meguro, W. Lu, W. Gao
    Procedia Engineering 19 337 - 342 2011年 [査読有り][通常論文]
     
    Surface characterization of an XY sinusoidal grating, which is fabricated by FTS (fast tool servo) on a diamond turning machine, is presented. The grating has a three dimensional micro-structured surface, which is a superposition of sinusoidal waves in the X- and Y-direction. The pitches and amplitudes of the sine waves are 10 ?m and 0.4 ?m, respectively. The surface form of the grating is imaged by a confocal microscope, a white light interference microscope and an atomic force microscope. The 3D images from the microscopes are compared with each other to distinguish the measurement uncertainties. The microscope images are analyzed by the two-dimensional discrete Fourier transform technique, which perfectly matches the nature of sinusoidal waves. The spatial spectrum of the grating surface is employed to identify the specific error factors introduced in the diamond turning process. © 2012 Published by Elsevier Ltd. Selection and peer-review under responsibility of Prof. E. Brinksmeier.
  • Bin Xu, Yuki Shimizu, Wei Gao
    Proceedings of SPIE - The International Society for Optical Engineering 8321 2011年 [査読有り][通常論文]
     
    This paper presents a micro-stylus probe, which is composed of a precision glass micro-ball and a shaft made by a glass tube. The diameter of the micro-ball was 50 μm. The tip angle of the glass-tube shaft was approximately 10 degrees. Strength test shows that the tolerance of glass tube micro-stylus against external forces is 90 mN. To reduce the stick-slip phenomena, a micro-tapping probe employing the glass tube micro-stylus and a PZT actuator was demonstrated. The micro-stylus probe was mounted to an air-bearing displacement sensor for scanning surface form metrology. Experimental results showed that the micro-tapping probe was effective for reducing the influence of the stick-slip phenomena. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).
  • Yuxin Peng, Yasumasa Sakurai, Yoshikazu Arai, Yuki Shimizu, Wei Gao
    Proceedings of SPIE - The International Society for Optical Engineering 8321 2011年 [査読有り][通常論文]
     
    This paper presents a linear-rotary micro-stage that can generate motions along and about the Z-axis using piezoelectric elements (PZTs). The small stroke of a PZT is extended by repeating the PZT motions based on a mechanism of impact friction drive. The friction drive mechanism has a simple driving unit, which only consists of a PZT element and a friction element. The moving element of the stage, which is a steel cylinder, is supported and actuated by a driving unit, which consists of two PZTs and a friction component made by permanent magnet. The magnetic force is employed for holding the moving element and stabilizing the driving condition. The dimension of the stage is 7.0 mm x 8.8 mm x 7.5 mm. The moving ranges of the stage are about 5.0 mm in the Z-direction and 360 degrees in the θ -direction, respectively. The maximum moving speeds are approximately 30 mm/s and 84 rpm in the two directions, respectively. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE). z
  • Jianhua Li, Junguo Xu, Yuki Shimizu, Masayuki Honchi, Kyosuke Ono, Yukio Kato
    Journal of Tribology 132 3 1 - 13 2010年07月 [査読有り][通常論文]
     
    Perturbation and modal-analysis methods were employed to systematically study a damped slider's dynamic characteristics, including an air-bearing slider's stiffness, damping coefficient, frequency response to translation and wavy motion, natural frequencies, damping ratios, and modal shape-node line. We found that a design with grooves distributed on a trailing pad effectively improved the slider's damping ratio in the second pitch mode; however, parametric studies revealed that the damping ratio was dependent on the number of grooves, their depth, location, width, length, distribution, orientation, and types. A higher damping ratio could be obtained by optimizing these parameters. The femto slider we designed with distributed damped grooves on a trailing pad had a higher damping ratio in the second pitch mode, and hence, its responses in the second pitch mode were greatly reduced, which were clarified through simulation and an experiment. Some issues on air-bearing stiffness reduction and negative damping at low frequency and contamination and lube pickup on the damped grooves were also evaluated in the experiment. No degradation could be found in the damped slider. © 2010 by ASME.
  • Masaru Furukawa, Junguo Xu, Yuki Shimizu, Yukio Kato
    Microsystem Technologies 16 1-2 221 - 226 2010年01月 [査読有り][通常論文]
     
    The mechanism for scratch-induced demagnetization was studied in perpendicular magnetic recording (PMR) disks. Scratches, which may occur on a disk's surface during head/disk contact, cause demagnetization, which results in read/write errors. Scratch-induced demagnetization is thus a serious issue. Scratch depths and demagnetization were compared using prototype PMR disks. We confirmed that demagnetization due to scratch depths were different because of the disk structures such as the cap and granular layers through observation using atomic force and magnetic force microscopy. We found that crystal planes in the grains of the granular layer slipped under the scratches, where demagnetization was observed from transmission electronic microscopy cross-sectional analyses of those disks. Scratch-induced demagnetization was mainly caused by plastic deformation of the grain due to crystal plane slippage in the granular layer. Therefore, a grain structure that is dense and cannot easily slip is needed to produce reliable hard disk drives. © 2009 Springer-Verlag.
  • Yuki Shimizu, Noritsugu Umehara, Junguo Xu
    Microsystem Technologies 16 1-2 293 - 299 2010年01月 [査読有り][通常論文]
     
    With the aim of reducing the lubricant-slider interaction by reducing slider surface energy, we fabricated several types of sliders with fluorine-ion-implanted (FII) air-bearing surfaces by using different levels of acceleration voltage for FII. With a low acceleration voltage, the fluorine-ions tended to be concentrated at shallower depths from the slider surface, and the contact angle of the water droplets was greater. The FII-treated slider showed lower touch-down height, which implies an improvement of slider stability at near-contact regime. The polar force component of the surface energy of FII-treated slider surface showed a good correlation with a thermally flying-height control heater power at touch-down. It is estimated that FII-treatment can reduce the polar force component of the surface energy and reduce the slider-lubricant interaction, resulting in a reduction of slider touch-down height. © 2009 Springer-Verlag.
  • Jianhua Li, Junguo Xu, Yuki Shimizu, Masayuki Honchi, Kyosuke Ono
    Proceedings of the ASME/STLE International Joint Tribology Conference 2009, IJTC2009 399 - 402 2010年 [査読有り][通常論文]
     
    Small perturbation and modal-analysis methods were employed to systematically study a damped slider's dynamic characteristics. We found that a design with grooves distributed on a trailing pad effectively improved the slider's damping at higher frequencies, and the damping ratio was dependent on the number of grooves, their depth, location, width, length, distribution, orientation, and types. A higher damping ratio could be obtained by optimizing these parameters. The femto slider with distributed damping grooves on a trailing pad had a higher damping ratio in the third mode, and hence, its responses to disk parallel and wavy motion were greatly reduced. This new design for the damped slider was an effective solution reducing the slider's modulation. © 2009 by ASME.
  • J. Xu, Y. Shimizu, H. Matsumoto, K. Matsuda
    Digest of the Asia-Pacific Magnetic Recording Conference 2010, APMRC 2010 47 7 1817 - 1822 2010年 [査読有り][通常論文]
     
    Study of lubricant coated slider showed that low slide surface energy has significant advantages in stable slider flying and less lubricant droplet formation on the disk surface at ultra-narrow clearance. Drive level evaluation showed the lubricant pick-up induced flying height increase is as one fifth low as control slider.
  • Yuki Shimizu, Kyosuke Ono, Noritsugu Umehara, Junguo Xu
    IEEE Transactions on Magnetics 45 10 3620 - 3623 2009年10月 [査読有り][通常論文]
     
    The effects of slider surface energy on slider dynamics were investigated with both a component-level experiment and a slider dynamics simulation with a 2-D head-disk interface model. The simulation results clearly show a reduction in the critical flying height, which was defined as the flying-height at the beginning of contact vibration, as same as a reduction in touchdown height observed in the experiment. According to the simulation results, the reduction of slider P2-mode vibration by the adhesion force in the near-contact region is considered to be effective in reducing slider touchdown height. Controlling slider surface energy is necessary for future low-flying head-disk interfaces. ©2009 IEEE.
  • Hui Li, Jianhua Li, Junguo Xu, Yuki Shimizu, Kyosuke Ono, Shinobu Yoshida
    2008 Proceedings of the STLE/ASME International Joint Tribology Conference, IJTC 2008 165 - 167 2009年 
    This work carries on a numerical simulation of the touchdown/takeoff (TD/TO) hysterisis of the spherical pad slider. It numerically studies the meniscus bridge's formation and meniscus force interaction between the spherical pad and lubricant over the disk surface. It proposes a geometry model for the lubricant bridge, and correspondingly, a force model for the meniscus force acting on the spherical pad slider due to the lubricant bridge. By solving the liquid balance state at the meniscus boundary, it obtains the geometry of the liquid bridge. A parametric study is done to study the effects of the geometry of spherical pad, Hamaker constant of lubricant-disk, and surface energy of lubricant on the formation of the liquid bridge. The overflow phenomenon is analyzed to find out the acceptable dimension of the spherical pad design. Moreover, a three-dimensional (3D) model of spherical pad slider/disk interface is built to study the steady-state flying of the spherical pad slider. The different parameters are analyzed to study their effects on the TD/TO hysteresis. Copyright © 2008 by ASME.
  • Masaru Furukawa, Junguo Xu, Yuki Shimizu, Yukio Kato
    IEEE Transactions on Magnetics 44 11 PART 2 3633 - 3636 2008年11月 [査読有り][通常論文]
     
    The mechanism of scratch-induced demagnetization was studied in perpendicular magnetic recording (PMR) disks. These scratches, which may occur on the disk's surface during head/disk contact, cause demagnetization that results in read/write errors. The scratchinduced demagnetization is thus investigated by the scratch test, observation of atomic force microscopy and magnetic force microscopy, and analysis of transmission electronic microscopy. It was found that the angle of the grain in the recording layer, which is vertically orientated on a PMR disk, was tilted under the scratch. These analyses revealed that scratch-induced demagnetization is caused mainly by plastic deformation which results in grain tilt in the recording layer, rather than by stress. Therefore, a dense and not-easily titled grain structure in the recording layer is needed to produce a reliable hard disk drive (HDD). © 2008 IEEE.
  • Toshiya Shiramatsu, Takenori Atsumi, Masayuki Kurita, Yuki Shimizu, Hideaki Tanaka
    IEEE Transactions on Magnetics 44 11 PART 2 3695 - 3697 2008年11月 [査読有り][通常論文]
     
    To achieve ultra-low flying height, magnetic spacing variations due to manufacturing tolerances and temperature-induced thermal protrusion need to be reduced. We have developed a thermal flying-height control (TFC) slider that carries a micro-thermal actuator. Previous TFC sliders were mainly statically controlled by a constant power supply. Our purpose is to demonstrate dynamic control of a TFC slider to compensate for high-speed magnetic signal modulation using feed-forward control methods. In this report, to dynamically compensate for magnetic signal modulation using TFC, two methods were examined. In method 1, TFC power was adjusted by using only time domain information. In Method 2, TFC power was adjusted by using frequency domain information in addition to time domain information. Method 2 showed better compensation for magnetic signal modulation due to better compensation at higher frequencies. These results showed that a dynamically controlled TFC slider is feasible in compensating for kilohertz order modulation. © 2008 IEEE.
  • Yuki Shimizu, Kyosuke Ono, Junguo Xu, Ryuji Tsuchiyama, Hidetoshi Anan
    Tribology Letters 30 3 161 - 167 2008年06月 [査読有り][通常論文]
     
    A slider with an air-bearing surface that has a small spherical pad around the read/write elements on the trailing center pad was developed to reduce the meniscus and friction forces and slider clearance loss. While the slider which has a spherical pad of a radius less than 10 mm, the meniscus force is reduced to less than 10% of the air-bearing lift force, thus, flying height modulation is decreased and instability are suppressed. Evaluation using an air-bearing surface model with a spherical pad showed that slider clearance was increased by 1 nm at a 5-nm nominal flying height. Evaluation using touchdown-takeoff testing of a spherical pad slider fabricated by depositing carbon on the center pad air-bearing surface by means of the lift-off resist technique showed that the spherical pad slider had a very small friction force and acoustic emission output up to a 5-nm interference height. It thus provides instability-free sliding in the near-contact regime. © 2008 Springer Science+Business Media, LLC.
  • Jianhua Li, Junguo Xu, Yuki Shimizu
    Journal of Tribology 129 4 712 - 719 2007年10月 [査読有り][通常論文]
     
    A simulation method in which grooves are virtually distributed on the slider air bearing instead of on the grooved medium surface has been developed and used to investigate the performance of sliders flying over the surface of a discrete-track medium. The simulated flying height loss due to a discrete-track medium coincides well with the measured data, whereas the average-estimation method overestimates flying height loss. Among the characteristics of a slider flying over the surface of a discrete-track medium that were studied are the flying attitude, the effect of groove parameters on flying profile, and the flying height losses due to manufacturing variation and altitude. The results indicate that when a slider is flying over the surface of a discrete-track medium, it will have a higher 3σ of flying height, be more sensitive to altitude, and will have a greater flying height loss. Copyright © 2007 by ASME.
  • Yuki Shimizu, Junguo Xu, Shozo Saegusa, Noritsugu Umehara
    Microsystem Technologies 13 8-10 811 - 816 2007年05月 [査読有り][通常論文]
     
    As a chemical modification of slider air bearing surface (ABS), fluorine ion implantation (FII) was conducted. FII treated ABS was fabricated to reduce slider surface energy, which is expected to reduce adhesion and friction force between the slider and disk. Tribological performance, such as slider flyability, was experimentally investigated. Touchdown speed, corresponds to a flying height of about 0.4 nm, was reduced by FII treatment. Slider touch-down and take-off hysteresis was also improved by reducing the adhesive force of the lubricant by fluorine-ion implantation. AE output and friction force were also reduced in the drag test. FII treated slider showed a 45% reduction of AE amplitude and 14% reduction of friction force. FII treatment was confirmed to be effective in improving slider flyability. © 2006 Springer-Verlag.
  • Jianhua Li, Junguo Xu, Yuki Shimizu
    Microsystem Technologies 13 8-10 981 - 986 2007年05月 [査読有り][通常論文]
     
    We investigated that what influence surface roughness had on the intermolecular forces acting at the head/disk interface. A model was developed based on a probabilistic description of the slider and disk surfaces. The results obtained from our research indicated that a rougher surface for the slider increased the intermolecular force slightely more than a smooth surface did. The intermolecular force on the slider was decreased by shifting the slider's mean plane. We concluded that it was possible in practice to design an air bearing surface with a lower intermolecular force using a smooth but narrower trailing-edge-pad, a textured/rough trailing pad with at least a 2-nm mean plane shift and a pitch angle designed larger than 100 μrad. © 2006 Springer-Verlag.
  • Jianhua Li, Junguo Xu, Yuki Shimizu
    Tribology Online 2 2 59 - 63 Japanese Society of Tribologists 2007年 [査読有り][通常論文]
     
    We have developed a simulation method in which grooves are virtually distributed on a slider air-bearing surface instead of on a grooved medium surface and used it to investigate slider flying performance. The characteristics of miniaturized air-bearing flying over a discrete track medium (DTM) with a sufficiently small mesh size are simulated minutely. The simulation results indicated that the air-bearing characteristics do not abruptly change when the DTM's land and groove sizes change from below to above the air mean free path. The "brush" shaped pressure distribution causes a larger shear stress difference between the DTM land and groove, which possibly leads to bigger lube moguls or ripples, and the shear stress on DTM land may make lube move into the groove from the land.
  • Yuki Shimizu, Junguo Xu
    IEEE Transactions on Magnetics 42 10 2516 - 2518 2006年10月 [査読有り][通常論文]
     
    A measurement system for flying-height modulation of magnetic heads is proposed, and two-dimensional (2-D) flying-height modulation mapping is demonstrated at the drive level. The measurement system is based on the triple harmonic method, which uses a readback signal from the read element of the magnetic head. This technique, which maintains a constant wavelength of the pattern for fly-height modulation measurement, was proposed to achieve 2-D flying-height modulation mapping. Moreover, the frequency response of the measurement system was calibrated, and measurement accuracy was improved. © 2006, IEEE. All rights reserved.
  • Jianhua Li, Junguo Xu, Yuki Shimizu
    Proceedings of STLE/ASME International Joint Tribology Conference, IJTC 2006 2006 2006年 
    A simulation method, in which grooves are virtually distributed on the slider air-bearing surface instead of on grooved medium surface, is developed to investigate slider flying ability fundamentally. Its feasibility is verified. The characteristics of a slider flying over a discrete track medium (DTM) surface are simulated, including the flying attitude, groove parameters effect on flying profile, 3 a flying height, and flying height sensitivity on altitude of the slider. Simulation results indicate that when a traditional slider is flying over a DTM surface, it will have a higher 3 sigma of flying height, a more sensitivity on altitude, and a bigger flying height loss. Copyright © 2006 by ASME.
  • Junguo Xu, Yuki Shimizu, Lizhi Su
    Proceedings of STLE/ASME International Joint Tribology Conference, IJTC 2006 2006 2 159 - 162 2006年 [査読有り][通常論文]
     
    A drive level measurement of flying height modulation and a demonstration of slider-disk contact control were conducted. The results of the flying height modulation strongly agree with those obtained from a LDV (Laser Doppler Vibrometer) measurement. The modulation was mainly caused by curvature caused by disk clamping. Furthermore, feedback control of a slider-disk contact was successfully demonstrated. Friction force was controlled at a small value to maintain the slider so that it flew over the disk in the light contact regime. Copyright © 2006 by ASME.
  • W. Gao, S. Dejima, Y. Shimizu, S. Kiyono
    CIRP Annals - Manufacturing Technology 52 1 435 - 438 2003年 [査読有り][通常論文]
     
    A prototype surface encoder consisting of a sinusoidal angle grid and a two-dimensional slope sensor is developed for two-axis position measurement. The angle grid has a three dimensional micro-structured surface, which is a superposition of periodic sinusoidal waves in the X- and Y-directions with spatial wavelengths of 150 μm and amplitudes of 100 nm over an area of up to 150 mm in diameter. The laser-based slope sensor is used to read local slope profiles of the grid surface. The X- and Y-positions together with tilt motions about the X-, Y- and Z-axes can be detected with resolutions of 0.1 μm and 1 arc-second through scanning a multi-spot laser beam across the grid surface at a constant speed.
  • 高偉,星野唯, 清水裕樹, 清野慧
    精密工学会誌 68 1 70 - 74 2002年01月05日 [査読有り][通常論文]
  • GAO W, 星野唯, 清水裕樹, 清野慧
    精密工学会誌 68 1 70 - 74 2002年 [査読有り][通常論文]
     
    This paper describes a surface encoder with a multi-spot light source. The surface encoder consists of an angle grid having a two-dimensional (2D) sinusoidal angular pattern on its surface, and a 2D angle sensor used to detect the 2D angle profile of the grid surface. The 2D XY displacements and tilt motions (pitch, roll and yaw) can be detected by the surface encoder. In this paper, a multi-spot light source is employed in the angle sensor. The multi-beams from the light source are projected onto the angle grid surface at the same phase positions in different periods. An averaging effect greatly reduces the effect of the dispersion of the pitch spaces of the angle grid, which acts as the measurement reference of the surface encoder. A laser diode and a grid film are combined to generate the multi-spot beams with pitch spaces of 300 μm, which are the same as those of the angle grid used in the experiments. The surface encoder with the multi-spot light source shows a good performance. A self-calibration technique is also applied to calibrate the surface encoder.
  • 清野慧, GAO W, 金井雅也, 星野唯, 清水裕樹
    精密工学会誌 67 3 493 - 497 2001年 [査読有り][通常論文]
     
    A new position detecting method, which uses a 2-D angle grid and a 2-D angle sensor, is proposed. The angle grid has a 2-D sinusoidal angular pattern on the surface. The relative displacements between the angle grid and the angle sensor in the X- and Y-directions can be detected from the output of the angle sensor. Because of the angle independency in the X- and Y- directions, it is possible to detect the X- and Y-directional positions from the 2-D angle sensor outputs. Furthermore, use of an optical scanning angle sensor, which scans a beam spot on the angle grid, can reduce the effect of the form error of the angle grid. Rolling and pitching can also be detected by using this method. In this paper, a scanning 2-D angle sensor is designed and manufactured. Experimental results of position detection are reported.
  • Satoshi Kiyono, Wei Gao, Masaya Kanai, Tadashi Hoshino, Yuki Shimizu
    Seimitsu Kogaku Kaishi/Journal of the Japan Society for Precision Engineering 67 3 493 - 497 2001年 [査読有り][通常論文]
     
    A new position detecting method, which uses a 2-D angle grid and a 2-D angle sensor, is proposed. The angle grid has a 2-D sinusoidal angular pattern on the surface. The relative displacements between the angle grid and the angle sensor in the X- and Y-directtons can be detected from the output of the angle sensor. Because of the angle independency in the X- and Y- directions, it is possible to detect the X- and Y-directional positions from the 2-D angle sensor outputs. Furthermore, use of an optical scanning angle sensor, which scans a beam spot on the angle grid, can reduce the effect of the form error of the angle grid. Rolling and pitching can also be detected by using this method. In this paper, a scanning 2-D angle sensor is designed and manufactured. Experimental results of position detection are reported.
  • 多自由度の位置と姿勢の精密検出法の研究
    清野慧, 高偉, 金井雅也, 星野唯, 清水裕樹
    精密工学会誌 2001年 [査読有り][通常論文]

書籍

  • 計測工学
    高偉, 清水裕樹, 羽根一博, 祖山均, 足立幸志 (担当:共著範囲:第3章,第11章,第12章)
    朝倉書店 2017年03月
  • Micro-Cutting: Fundamentals and Applications
    Wei Gao, Kang Won Lee, Young-Jin Noh, Yoshikazu Arai, Yuki Shimizu (担当:共著範囲:Chapter 11: In-Process Micro/Nano Measurement for Micro Cutting)
    Wiley 2013年
  • Nanofabrication
    Yuki Shimizu, Takemi Asai, Wei Gao (担当:共著範囲:Chapter X)
    INTECH 2011年10月 (ISBN: 9789533079127)

講演・口頭発表等

  • 精密エンコーダによる多軸精密計測  [招待講演]
    清水 裕樹
    一般社団法人電気学会 精密サーボシステムに関する調査専門委員会 2018年09月 口頭発表(招待・特別)
  • 松隈啓, 清水裕樹, 高偉
    精密工学会大会学術講演会講演論文集 2018年09月
  • 清水裕樹, 松野優紀, 石田彩華, 松隈啓, GAO Wei
    精密工学会大会学術講演会講演論文集 2018年08月
  • Development of a prototype micro thermal sensor probe for non-destructive surface defect detection  [通常講演]
    Yuki Shimizu, Yuki Matsuno, Hiraku Matsukuma, Wei Gao
    6th International Conference on Nanomanufacturing (nanoMan2018) 2018年07月 口頭発表(一般)
  • Uncertainty analysis of a six-degree-of-freedom surface encoder for a planar motion stage  [通常講演]
    Yuki Shimizu, Masaya Furuta, Yuan-Liu Chen, Xiuguo Chen, Hiraku Matsukuma, Wei Gao
    The 15th CIRP Conference on Computer Aided Tolerancing (CIRP CAT 2018) 2018年06月 口頭発表(一般)
  • 清水裕樹, 松野優紀, CHEN Yuan‐Liu, 松隈啓, GAO Wei
    精密工学会大会学術講演会講演論文集 2018年03月
  • Kentaro Uehara, Yuki Shimizu, Yuan Liu Chen, Wei Gao
    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2017 2017年11月 
    In this paper, a measurement method with a mode-locked laser source for evaluation of grating periods, which is based on the laser diffraction method with the Littrow configuration, is proposed. Optical frequencies of the mode-locked laser, which are referred to as the optical frequency comb, have deterministic mode frequencies with equal intervals in the frequency domain. Since the frequency of each comb mode can be highly stabilized by a high precision external standard, measurement accuracy of the laser diffraction method is expected to be improved. In this study, a prototype optical setup based on the proposed method is developed, and some experiments are carried out to verify the feasibility of the proposed method.
  • Keisuke Adachi, Takuma Sugawara, Yuki Shimizu, Yuan Liu Chen, Wei Gao, Eiji Niwa, Yoshihiro Sasaki
    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2017 2017年11月 
    This paper presents a design study of an XYZ three-axis micro stage which achieves a size of several cubic centimeters, a millimetric travel range, a nanometric driving resolution and three-axis motion at the same time. In addition, unique leaf springs acting not only as guides for a stage table but also as precision displacement sensors are included in the stage system. The XYZ three-axis micro stage is designed and fabricated. The fabricated stage is designed to have a small size of 25 mm (X) × 25 mm (Y) × 6.5 mm (Z). Furthermore, feasibility of the driving principle of the developed XYZ three-axis micro stage is verified in experiments.
  • Xiuguo Chen, Zongwei Ren, Yuanliu Chen, Yuki Shimizu, Wei Gao
    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2017 2017年11月 
    In this work, we establish a three-dimensional (3D) polarization ray-tracing model to trace the evolution of polarization states of incident beams through the corner-cube-like interferometer unit of an orthogonal two-axis Lloyd's mirror interferometer. Compared with the conventional two-dimensional Jones matrix formalism, the 3D polarization ray-tracing model that represents polarization as a three-element electric field vector in the global coordinate system provides an easier approach to trace the polarization evolution. The comparison between the simulated and experimental interference fringes obtained under different combinations of initial polarization states of incident beams verify the feasibility of the established model.
  • Toshiki Saito, Yuki Machida, Yuki Shimizu, Yuan Liu Chen, Wei Gao
    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2017 2017年11月 
    This paper proposes a new surface form measurement method using a scanning type surface profiler for small roll worlpieces, which are used in many industrial fields. In this method, inclination of a workpiece is required to be aligned precisely. For this reason, this paper also proposes a method of measuring the inclination angle of the workpiece without using any other external sensors but using a scanning probe of the surface profiler. In order to confirm the effectiveness of the proposed principles, a measurement system is developed and some experiments are carried out.
  • Zengyuan Niu, Yuan Liu Chen, Yuki Shimizu, Wei Gao
    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2017 2017年11月 
    This paper presents a method for the measurement of relative vertical error motions with respect to vertical misalignment error of a bench center by using an optical micrometer. A roll is used as a reference object and the optical micrometer are employed as a measurement device. In order to achieve an accurate evaluation, a measurement method is proposed to remove the straightness error and the concentricity error of the roll. Through experiment, the relative vertical parallelism error motion with respect to the misalignment error was evaluated to be 1.44 um and the vertical straightness error was evaluated to be 14.01 um.
  • Shuhei Madokoro, Yuki Shimizu, Yuan Liu Chen, Wei Gao
    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2017 2017年11月 
    This paper presents a new optical angle sensor, in which a mode-locked laser referred to as an optical frequency comb is employed as the light source. Highly-stable carrier frequency of the optical frequency comb is expected to improve the sensor stability. This angle sensor is designed based on laser autocollimation method, and utilizes the chromatic dispersion of an objective lens to detect angular displacement of a measurement target. A detail of the proposed method is described, followed by some experimental results with the developed prototype optical sensor.
  • Yuki Shimizu, Taku Nakamura, Yuan Liu Chen, Wei Gao
    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2017 2017年11月 
    An optical configuration for a confocal microscope employing a mode-locked laser source is proposed in this paper. Due to high illumination efficiency and a highly stable optical frequency of the mode-locked laser, which is traceable with the national standard of frequency and time, the proposed chromatic confocal microscope is expected to achieve a high axial resolution. In this paper, as a first step of research, design study on the optical setup for the prototype chromatic confocal microscope with the mode-locked laser is carried out.
  • Kazuki Mano, Ryo Aihara, Yuki Shimizu, Yuan Liu Chen, Wei Gao
    Proceedings of the 9th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2017 2017年11月 
    This paper presents an optical setup to fabricate a large-area two-dimensional diffraction grating by using a two-axis Lloyd's mirror interferometer. In order to fabricate large-area gratings, a large collimating lens, which generates a large diameter collimated beam, is integrated into the optical setup. In this paper, an evaluation of the intensity distribution of the collimated beam and an exposure experiment are carried out. In addition, the fabricated grating is measured by an atomic force microscope to evaluate the effectiveness of the developed setup with the large collimating lens.
  • EVALUATION OF A FOCUSED LASER SPOT DIAMETER FOR AN OPTICAL ANGLE SENSOR  [通常講演]
    The 59th Ilmenau Scientific Colloquium 2017年09月 口頭発表(一般) ドイツ Ilmenau
  • 清水裕樹, 中川翔太, CHEN Yuan‐Liu, GAO Wei
    精密工学会大会学術講演会講演論文集 2017年09月
  • Optical Instruments for Measurement of the Next-generation Stage Systems for Dimensional Metrolog  [招待講演]
    清水 裕樹
    Optical Society of Korea OSK-OSJ Joint Symposium 2017年07月 口頭発表(招待・特別)
  • Optical Instruments for Measurement of the Next-generation Stage Systems for Dimensional Metrology  [通常講演]
    Optical Society of Korea Summer Meeting 2017 2017年07月 口頭発表(招待・特別) 韓国 釜山
  • Quantitative evaluation of a cutting tool edge geometry by using a micro laser probe  [通常講演]
    39th International MATADOR Conference on Advanced Manufacturing (Matador 2017) 2017年07月 口頭発表(一般) イギリス Manchester
  • 清水裕樹, 松野優紀, CHEN Yuan‐Liu, GAO Wei
    精密工学会大会学術講演会講演論文集 2017年03月
  • Yindi Cai, Yuan Liu Chen, Yuki Shimizu, So Ito, Wei Gao
    2016 IEEE 11th Annual International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2016 2016年11月 
    © 2016 IEEE. Molecular dynamics simulations of contact mode form measurement process on a soft substrate with a special surface profile using a diamond AFM tip are preformed to investigate the contact behavior and the surface profile damages or distortions of the measured substrate. The process of contact mode imaging of the AFM can be treated as the process of nano-scratching. The simulation-predicted interaction force, including scratching force and normal force, characterizes the saw-tooth pattern, which is referred to as atomic stick-slips. The shape of measured substrate surface, especially the surface underneath the AFM tip, is distorted by the interaction force between the AFM tip and the substrate surface.
  • Yuki Shimizu, Yuki Matsuno, Yuta Ohba, Wei Gao
    16th International Conference on Nanotechnology - IEEE NANO 2016 2016年11月 
    © 2016 IEEE. This paper presents a concept of a micro thermal sensor to be used for defect inspection of a smoothly-finished surface such as a bare wafer or a hard disk. In the proposed concept, existences of the defects on a measurement surface will be detected by scanning the surface with the micro thermal sensor, which is utilized to detect the variation of the thermal flow in-between the sensor surface and the measurement surface. The proposed micro thermal sensor has a possibility of detecting various types of surface defects. An existence of the defect having a convex shape such as an asperity or a particle can be found by detecting a heat generated at the collision between the sensor surface and the tip of the defect. In addition, the thermal sensor is expected to be applied for the inspection of pits or scratches in a concave shape on the smooth surface. When the thermal sensor is placed with respect to the measurement surface with a tiny gap of less than 1 μm, a heat transfer system sensitive against the gap variation will be constructed at the interface between the thermal sensor and the measurement surface becomes a system.
  • Zongwei Ren, Ryo Aihara, Yuki Shimizu, So Ito, Yuan Liu Chen, Wei Gao
    16th International Conference on Nanotechnology - IEEE NANO 2016 2016年11月 
    © 2016 IEEE. This paper presents the analysis of an orthogonal multi-beam Lloyd's mirror interferometer for fabrication of two-axis gratings, which is employed as a measurement standard. Conventionally, for the fabrication of such complicated micro patterns, ultra-precision turning with a fast tool servo or lithography process with masks has been employed. However, they require long machining or fabrication time. Meanwhile, laser interference lithography such as the Lloyd's mirror interferometer is expected as a candidate for fabrication of such periodic micro patterns. In this paper, a new optical configuration is designed based on the Lloyd's mirror interferometer. In the proposed design, differing from the one in the previous study, two mirrors and a substrate are set to be perpendicular with each other to fabricate two-axis grating patterns having both symmetric profiles and uniform depths over the wide fabrication area, which has been difficult to be achieved in the previous study. A design and fabrication of the optical configuration for the orthogonal multi-beam Lloyd's mirror interferometer, and some experimental results with the interferometer will be reported.
  • Zengyuan Niu, Ryo Kobayashi, Yuan Liu Chen, Yuki Shimizu, So Ito, Wei Gao
    16th International Conference on Nanotechnology - IEEE NANO 2016 2016年11月 
    © 2016 IEEE. This paper presents nanometrology of an ultraprecision machined surface by using optical sensors. To verify the feasibilities of optical sensors on the measurement of surface profile, different types of fiber-optic sensor and laser micro interferometer are employed to measure the roundness of a ultraprecision machined cone in this paper. Experiments confirmed that the fiber-optic sensor can measure not only the roundness but also the surface roughness of the cone. Experiments also confirm that the measurement of the laser micro interferometer is highly affected by the surface roughness of the cone because of the relative measurement principle of the laser micro interferometer.
  • Computer simulation on the optical configuration of an ultra-sensitive angle sensor based on laser autocollimation  [通常講演]
    16th International Conference on Precision Engineering (ICPE 2016) 2016年11月 口頭発表(一般) 日本国 浜松
  • A design study of an XYZ micro-stage  [通常講演]
    The 7th International Conference on Positioning Technology (ICPT2016) 2016年11月 口頭発表(一般) 韓国 Seoul
  • A sensitivity-improved micro thermal sensor for surface defect inspection  [通常講演]
    The 12th Chinese-Japan International Conference on Ultra-Precision Manining Process 2016年11月 口頭発表(一般) 中国 Hunan
  • 清水裕樹, 菅原拓馬, 安達圭祐, 伊東聡, GAO Wei, 丹羽英二, 佐々木祥弘
    日本機械学会年次大会講演論文集(CD-ROM) 2016年09月
  • 伊東聡, CHEN Yuanliu, 菊地浩貴, 清水裕樹, GAO Wei, 高橋和彦, 金山利彦, 荒川訓明, 林敦
    日本機械学会年次大会講演論文集(CD-ROM) 2016年09月
  • Micro Thermal Sensor for Nanometric Surface Defect Inspection  [通常講演]
    IEEE NANO 2016 (16th International Conference on Nanotechnology) 2016年08月 口頭発表(招待・特別) 日本国
  • 伊東聡, 菊地浩貴, 小林遼, CHEN Yuan‐Liu, 清水裕樹, GAO Wei, 高橋和彦, 金山利彦, 荒川訓明, 林敦
    精密工学会大会学術講演会講演論文集 2016年08月
  • Investigation on the sensitivity of an optical angle sensor based on laser autocollimation  [通常講演]
    International Symposium on Optoelectronic Technology and Application 2016 (OTA 2016) 2016年05月 口頭発表(招待・特別) 中国
  • 菊地浩貴, 伊東聡, 陳遠流, 清水裕樹, GAO Wei, 高橋和彦, 金山利彦, 荒川訓明, 林敦
    精密工学会大会学術講演会講演論文集 2016年03月
  • 清水裕樹, 松野優紀, 大場裕太, GAO Wei
    精密工学会大会学術講演会講演論文集 2016年03月
  • Laser interference lithography with a modified two-axis Lloyd’s mirror interferometer for fabrication of two-dimensional micro patterns  [通常講演]
    The 8th International Conference on Leading Edge Manufacturing in 21st Century (LEM21) 2015年10月 口頭発表(一般)
  • Yuan Liu Chen, Yindi Cai, Keisuke Tohyama, Yuki Shimizu, So Ito, Wei Gao
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月 
    This paper presents an experimental investigation of ductile cutting of silicon by using a diamond tool with a negative rake angle. A diamond cutting tool with a zero rake angle is inclined to form a negative rake angle for a better performance in ductile cutting. A high-sensitivity force sensor is integrated with the tool holder for detection of the tool-sample contact and monitoring the thrust force in the cutting process. The unavoidable sample tilt was probed by using the force sensor integrated diamond tool as a stylus, so that microstructures can be directly fabricated along the tilted workpiece. With accurate tilt compensation, a microstructure array with a good uniformity was successfully fabricated on the silicon surface.
  • Jun Tamada, Yukitoshi Kudo, Yuan Liu Chen, Yuki Shimizu, So Ito, Wei Gao
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月 
    This paper proposes a new optical angle sensor, in which a mode-locked femtosecond laser referred to as an optical frequency comb is employed as a light source. By using the optical frequency comb whose carrier frequency is well stabilized by using an external frequency standard with an uncertainty of 10 -11 , both the sensor stability and the sensor sensitivity are expected to be improved. In this paper, a prototype optical sensor head with the femtosecond laser for the angle sensor is fabricated. Since the light wavelength of the femtosecond laser used in this paper is out of the visible range, a new alignment method using a retroreflector is introduced to determine the origin position of the angle sensor. In addition, some basic experiments are carried out to verify the feasibility of the developed angle sensor with the optical frequency comb.
  • Minglei Li, Zhigang Jia, So Ito, Yuki Shimizu, Wei Gao
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月 
    In this research, a long stroke atomic force microscope (LS-AFM) is developed for surface profile measurement of micro-optics with steep sidewalls. An electrochemically polished tungsten probe with sharpened apex is employed as the AFM probe which provides the effective length of the probe tip more than 100 μm so that the accessibility to the valley part of a deep groove can be realized. The probe tip is vibrated by a tuning fork at their resonance frequency. The probe tapping the sample surface with constant force which is feedback controlled based on the constant frequency shift signal of the tuning fork. The trace of the probe tip in Z direction can be considered as the sample surface profile. Sectional profile measurement of a Fresnel lens is carried out by utilizing the LS-AFM and a commercial optical probe. The comparison of the measurement result demonstrates the effectiveness and the advantage of the developed LS-AFM in profile measurement of micro-optics with steep sidewalls.
  • So Ito, Kikuchi Hirotaka, Yuan Liu Chen, Yuki Shimizu, Wei Gao
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月 
    A prototype measurement system by using a micro-probe is introduced for the precision measurement of the slit width. The stylus of the micro-probe is consisted of the thermally-pulled capillary glass tube and precision glass ball with 50 μm in diameter, so that the probe tip can be inserted into the inside of the micro-gap. A shear-force detection micro-probing is employed for the precision measurement of the slit width of the slot die coater. The measurement accuracy of the slit width measurement is investigated.
  • Shigeaki Goto, Minglei Li, Zhigang Jia, So Ito, Yuki Shimizu, Wei Gao
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月 
    This paper reports the experimental result of noncontact surface profile measurement of an insulating sample made of glass with the developed electrostatic force microscope (EFM). Noncontact scanning was carried out maintaining the tip-to-sample distance of larger than 100 nm, which significantly reduces the risk of collision between the sample and the tip. The algorism named "dual-height method" calculated the profile image with cancelling the fluctuation of the tip-to-sample distance. The same sample was measured also with the AFM, and the EFM profile images agreed with the AFM profile image quantitatively.
  • Satoshi Kataoka, Tatsuya Ishikawa, Yuki Shimizu, So Ito, Wei Gao
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月 
    This paper presents measurement of the angular error motions of a precision linear stage by using a high resolution clinometer in the production process of the stage, where the measurement is repeatedly carried out together with a hand scraping operation for correction of the form errors of the stage guideways. Differing from a conventional autocollimator, the clinometer does not require a reference mirror on the stage since its angle reference is the direction of the gravitational vector. In this paper, two clinometers are employed to measure roll error motion of a linear stage, while eliminating the influences of external vibrations.
  • Zengyuan Niu, Yuanliu Chen, Daiki Matsuura, Ryo Kobayashi, Yuki Shimizu, So Ito, Wei Gao, Jeongseok Oh, Chunhong Park
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月 
    This paper presents a measurement method for vertical straightness of a roll workpiece on an ultra-precision lathe. The measurement of vertical straightness of a roll workpiece is directly influenced by the vertical error motions of carriage slide, which is composed of the out-of-straightness error component and the out-of-parallelism error component. The effect by the vertical error motions should be compensated in the measurement of vertical straightness of a roll workpiece. A three-probe method and new algorithms are employed to measure and evaluate both the vertical straightness and the vertical error motions, which are newly introduced. Experiments are carried out on a small roll workpiece.
  • Yindi Cai, Yuanliu Chen, Yuki Shimizu, So Ito, Wei Gao, Ying Chen
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月 
    This paper presents molecular dynamics simulation on nanoindentation of diamond indenter on a copper workpiece. Surface damages of the workpiece are caused in the contact detection process for ultra-precision fabrication and form measurement of surface by using a force sensor-integrated fast tool servo. Molecular dynamics simulations are carried out in this paper to theoretically investigate the geometries of the damages due to the contact deformation. Taking into consideration of the holding period at the maximum indentation depth between the loading and the unloading processes, the dependence of the indentation geometry on the holding time are observed. Based on the simulation results, physical properties of the workpiece are also analyzed.
  • Yindi Cai, Xinghui Li, Xinghui Li, Ryo Aihara, Yuki Shimizu, So Ito, Wei Gao
    Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 2015年10月 
    This paper presents a design study on an optical setup for fabrication of a two-dimensional grating used in encoder systems. By adding major modifications to the conventional one-axis Lloyd's mirror interferometer, a modified two-axis Lloyd's mirror interferometer has been developed. Based on the wave optics, the two-axis interference patterns to be generated by the proposed optical configuration are simulated. To eliminate unwanted distortion of the two-dimensional micro patterns, polarization of the laser beams is controlled by inserting two half wave plates in the optical path. In addition, pattern exposure tests are carried out by using a prototype optical setup.
  • 伊東聡, 関根匠, 清水裕樹, GAO Wei, 高橋和彦, 荒川訓明, 山本泰河, 久保田晃史
    日本機械学会年次大会講演論文集(CD-ROM) 2015年09月
  • 清水裕樹, NIU ZengYuan, 松浦大貴, 小林遼, 伊東聡, GAO Wei
    日本機械学会年次大会講演論文集(CD-ROM) 2015年09月
  • 松野優紀, 大場裕太, 清水裕樹, GAO Wei
    精密工学会大会学術講演会講演論文集 2015年08月
  • 小林遼, 清水裕樹, 伊東聡, GAO Wei, 足立茂, 大宮恭平, 佐藤友樹
    精密工学会大会学術講演会講演論文集 2015年08月
  • 大野敦子, KIM WooJae, CAI Yindi, CHEN Yuan‐Liu, 清水裕樹, 伊東聡, GAO Wei
    精密工学会大会学術講演会講演論文集 2015年08月
  • 中川翔太, JANG SungHo, 清水裕樹, 伊東聡, GAO Wei
    精密工学会大会学術講演会講演論文集 2015年08月
  • 伊東聡, 石川龍弥, 片岡智史, CHEN Yuan‐Liu, 清水裕樹, GAO Wei
    精密工学会大会学術講演会講演論文集 2015年08月
  • 清水裕樹, 玉田純, 工藤幸利, CHEN Yuan‐Liu, 伊東聡, GAO Wei
    精密工学会大会学術講演会講演論文集 2015年08月
  • 相原涼, LI Xinghui, CAI Yindi, 伊東聡, 清水裕樹, GAO Wei
    精密工学会大会学術講演会講演論文集 2015年08月
  • 古田雅也, LI Xinghui, CAI Yindi, 清水裕樹, 伊東聡, GAO Wei
    精密工学会大会学術講演会講演論文集 2015年08月
  • 片岡智史, 石川龍弥, CHEN Yuan‐Liu, 清水裕樹, 伊東聡, GAO Wei
    精密工学会大会学術講演会講演論文集 2015年08月
  • 丸山泰司, 清水裕樹, 伊東聡, GAO Wei
    精密工学会大会学術講演会講演論文集 2015年08月
  • 町田裕貴, 清水裕樹, 伊東聡, GAO Wei, 山崎宏, 柴本裕輔, 花岡浩毅
    精密工学会大会学術講演会講演論文集 2015年08月
  • 菅原拓馬, 清水裕樹, 伊東聡, GAO Wei, 丹羽英二, 佐々木祥弘
    精密工学会大会学術講演会講演論文集 2015年08月
  • 伊東聡, JIA Zhigang, LI Minglei, 清水裕樹, GAO Wei
    精密工学会大会学術講演会講演論文集 2015年03月
  • 丸山泰司, 清水裕樹, 伊東聡, GAO Wei, TAN Siew Leng
    精密工学会大会学術講演会講演論文集 2015年03月
  • 清水 裕樹, 牛 増渊, 松浦 大貴, 小林 遼, 伊東 聡, 高 偉
    年次大会 2015年 
    This paper presents a development of a method and a system for on-machine measurement of horizontal and vertical motion errors of a carriage slide in a machine tool and form errors of roll dies including deformation due to gravity. Conventional reversal methods cannot have measured deflection of roll dies due to its principle. To realize further higher fabrication accuracy of the roll dies, a new reversal method employing a straightedge and three displacement sensors is proposed for measurement of roll dies. In the proposed method, by using the outputs from the displacement sensors, the deflection of the roll dies can be measured while cancelling the influence of the carriage slide motion error. An on-machine measurement system consisting of a small roll work-piece and three capacitive displacement sensors is constructed on an ultra-precision lathe. Experimental results confirmed that the developed system has stability enough to achieve required measurement uncertainty of ±100 nm.
  • 伊東 聡, 関根 匠, 清水 裕樹, 高 偉, 高橋 和彦, 荒川 訓明, 山本 泰河, 久保田 晃史
    年次大会 2015年 
    This paper presents the development of the contact-type displacement probe with low measuring force for the profile measurement of the cutting edge on-machine and non-damaging. This probe is consisted of a triangulation-based laser displacement sensor and both-ends supported leaf spring, on which a stylus tip will be mounted. The displacement of the stylus tip can be measured by detecting the deflection of the leaf spring with the laser displacement sensor. The probe is mounted on the linear stage to scan the cutting edge. To realize the large measurement range and low measurement force, the probe tip is contacted intermittently in the vertical direction. The low measurement force of less than 0.1 mN can be achieved. The measurement accuracy is evaluated, and then, the profile of the sharpened edge is measured by utilizing the developed probe system.
  • Xinghui Li, Xinghui Li, Yindi Cai, Ryo Aihara, Yuki Shimizu, So Ito, Wei Gao
    Proceedings of SPIE - The International Society for Optical Engineering 2015年01月 
    © 2015 SPIE. This paper presents a fabrication method of two-dimensional micro patterns for adaptive optics with a micrometric or sub-micrometric period to be used for fabrication of micro lens array or two-dimensional diffraction gratings. A multibeam two-axis Lloyd's mirror interferometer is employed to carry out laser interference lithography for the fabrication of two-dimensional grating structures. In the proposed instrument, the optical setup consists of a light source providing a laser beam, a multi-beam generator, two plane mirrors to generate a two-dimensional XY interference pattern and a substrate on which the XY interference pattern is to be exposed. In this paper, pattern exposure tests are carried out by the developed optical configuration optimized by computer simulations. Some experimental results of the XY pattern fabrication will be reported.
  • 清水裕樹, 大場裕太, GAO Wei
    精密工学会大会学術講演会講演論文集 2014年09月
  • JANG SungHo, 清水裕樹, GAO Wei
    日本機械学会東北支部総会・講演会講演論文集(CD-ROM) 2014年03月
  • LI Xinghui, 清水裕樹, 伊東聡, GAO Wei
    日本機械学会東北支部総会・講演会講演論文集(CD-ROM) 2014年03月
  • 伊藤武志, LI Xinghui, 清水裕樹, 伊東聡, GAO Wei
    精密工学会大会学術講演会講演論文集 2014年03月
  • 清水裕樹, JANG SungHo, GAO Wei
    精密工学会大会学術講演会講演論文集 2014年03月
  • 村田大, 清水裕樹, 伊東聡, GAO Wei
    精密工学会大会学術講演会講演論文集 2014年03月
  • 細渕啓一郎, JIA Zhigang, 伊東聡, 清水裕樹, GAO Wei
    精密工学会大会学術講演会講演論文集 2014年03月
  • 張 城豪, 清水 裕樹, 高 偉
    東北支部総会・講演会 講演論文集 2014年
  • 清水裕樹, 伊藤武志, LI Xinghui, KIM WooJae, GAO Wei
    砥粒加工学会学術講演会講演論文集(CD-ROM) 2014年
  • 李 星輝, 清水 裕樹, 伊東 聡, 高 偉
    東北支部総会・講演会 講演論文集 2014年
  • 賈 志剛, 細渕 啓一郎, 伊東 聡, 清水 裕樹, 高 偉
    東北支部総会・講演会 講演論文集 2014年
  • Jacob W. Chesna, Jacob W. Chesna, Yuki Shimizu, Yuki Shimizu, Richard, K. Leach
    Proceedings of the 28th Annual Meeting of the American Society for Precision Engineering, ASPE 2013 2013年12月
  • Gaofa He, Gaofa He, Zhigang Jia, So Ito, Yuki Shimizu, Wei Gao
    Proceedings of SPIE - The International Society for Optical Engineering 2013年12月 
    For measuring the surface profile of many micro-optical components which are made of non-conductive material, such as diffractive grating and Fresnel lens, with complicated shapes on their surfaces, the electrostatic force microscopy (EFM) was recommended in noncontact condition. When a bias voltage is applied between the conducting probe tip and a back electrode where a non-conducting sample was put on, an electrostatic force will be generated between the probe tip and the sample surface. The electrostatic force will change with the distance between the probe tip and the sample surface. Firstly, the relationship between the electrostatic force and the tip-sample distance was analyzed based on the dielectric polarization theory. The theoretical result shows that the electrostatic force is proportional to 1/d2, where d is the distance between the probe tip and sample surface. Then, a numerical method (finite element method -FEM) was employed to calculate the electrostatic force and the result shows accordance with the theoretical method. Finally, the prototype of a scanning electrostatic force microscopy was built which is composed of a conducting probe unit with a Z scanner driven by piezoelectric actuators, a XY scanner unit for mounting the sample and back electrode and a circuit unit for detecting the frequency shift. The force curve, which shows the relationship between the electrostatic force and the tip-sample distance, was achieved by using the EFM prototype. All results demonstrated that it is feasible for using the EFM system to measure the surface profile of non-conductor. © 2013 SPIE.
  • 接触型マイクロ熱検知センサによるナノ平滑面微欠陥検出に関する研究  [通常講演]
    大場裕太, 盧文剣,高偉
    精密工学会秋季大会 2013年09月 口頭発表(一般)
  • 清水裕樹, 大場裕太, LU Wenjian, GAO Wei
    精密工学会大会学術講演会講演論文集 2013年08月
  • Feasibility study on the concept of thermal contact sensor for nanometer-level defect inspections on smooth surfaces  [通常講演]
    Wenjian LU, Yuta OHBA, Wei GAO
    THE 11th INTERNATIONAL SYMPOSIUM OF MEASUREMENT TECHNOLOGY ANDINTELLIGENT INSTRUMENTS 2013年07月 口頭発表(一般) ドイツ
  • Zhigang Jia, Shigeaki Goto, Keiichiro Hosobuchi, So Ito, Yuki Shimizu, Wei Gao
    Proceedings of SPIE - The International Society for Optical Engineering 2013年04月 
    This paper presents the analysis of a prototype scanning electrostatic force microscope (SEFM) system developed for noncontact surface profile measurement. In the SEFM system, with a dual height method, the distance between the probe tip and the sample surface can be accurately obtained through removing the influence of the electric field distribution on the sample surface. Since the electrostatic force is greatly influenced by the capacitance between the probe tip and the sample surface, a new approach for modeling and analysis of the distribution of capacitance between the probe tip with an arbitrary shape and the sample surface with a random topography by using the finite difference method (FDM) is proposed. The electrostatic forces calculated by the FDM method and the conventional sphere-plane model are compared to verify the validity of the FDM method. The frequency shift values measured by experiment are also compared with the simulation results computed by the FDM method. It has been demonstrated that the electrostatic force between arbitrary shapes of the probe tip and the sample surface can be well calculated by the finite difference method. © 2013 SPIE.
  • Xinghui Li, Yuki Shimizu, So Ito, Wei Gao, Lijiang Zeng
    Proceedings of SPIE - The International Society for Optical Engineering 2013年04月 
    To fabricate a scale grating for a surface encoder in a cost-effective way, a blue laser diode with a wavelength of 405 nm is employed in a Lloyd's mirror interferometer to carry out interference lithography (IL) of the grating. The beams from the laser diode are collimated by an aspherical collimating lens to form beams with a diameter of 50 mm. These beams are then projected towards the Lloyd's mirror and the grating substrate, which are aligned perpendicularly with each other and are mounted on a rotary stage. One half of the beam directly goes to the grating substrate, and the other half reaches to the grating substrate after being reflected by the mirror. The direct beam and the reflected beam interference with each other to generate and expose the interference fringes, which correspond to the scale grating structures, on the substrate coated with a photoresist layer. The pitch and area of the grating structures are set to be 570 nm and around 300 mm 2, respectively. The fabricated grating structures are evaluated with an AFM to investigate the influence of the spectrum width of the laser beam. © 2013 SPIE.
  • 細渕啓一郎, JIA Zhigang, 伊東聡, 清水裕樹, HE Gaofa, GAO Wei
    日本機械学会東北支部総会・講演会講演論文集 2013年03月
  • 大澤慎一, 関根匠, 伊東聡, 清水裕樹, GAO Wei, 久保田晃史, 加藤明, 荒川訓明, 安竹睦実
    日本機械学会東北支部総会・講演会講演論文集 2013年03月
  • 目黒孝幸, 松浦大貴, 清水裕樹, 伊東聡, GAO Wei, 足立茂, 大宮恭平
    日本機械学会東北支部総会・講演会講演論文集 2013年03月
  • 村田大, 清水裕樹, 伊東聡, GAO Wei
    精密工学会大会学術講演会講演論文集 2013年02月
  • 大澤 慎一, 関根 匠, 伊東 聡, 清水 裕樹, 高 偉, 久保田 晃史, 加藤 明, 荒川 訓明, 安竹 睦実
    東北支部総会・講演会 講演論文集 2013年
  • 目黒 孝幸, 松浦 大貴, 清水 裕樹, 伊東 聡, 高 偉, 足立 茂, 大宮 恭平
    東北支部総会・講演会 講演論文集 2013年
  • 細渕 啓一郎, 賈 志剛, 伊東 聡, 清水 裕樹, 何 高法, 高 偉
    東北支部総会・講演会 講演論文集 2013年
  • 盧 文剣, 大場 裕太, 清水 裕樹, 高 偉
    東北支部総会・講演会 講演論文集 2013年
  • J. Xu, Y. Shimizu, J. Liu, T. Shiramatsu, M. Furukawa, J. Li, H. Kohira
    2012 Digest APMRC - Asia-Pacific Magnetic Recording Conference: A Strong Tradition. An Exciting New Look! 2012年12月 
    Pit detection study of a thermal contact sensor was carried out by both experiments and simulation. The experimental results showed that the thermal contact sensor was able to detect a small pit with good sensitivity. And the simulation study revealed that the mechanism of pit detection is due to worse cooling, which results in higher sensor temperature, because the sensor/disk spacing is larger on the pit. The maximum temperature increase is significant initially with increasing pit depth but saturates when the depth is larger than 60 nm. © 2012 DSI.
  • Kang Won Lee, So Ito, Yuki Shimizu, Wei Gao, Katsutoshi Tanaka, Masahiko Fukuta, Yoshiaki Kai
    2012 IEEE I2MTC - International Instrumentation and Measurement Technology Conference, Proceedings 2012年07月 
    This paper presents the experimental investigations for performance evaluation of an air-bearing displacement sensor as a measurement system for nanometrology of surface forms by using it. The experimental configuration and some considerations for the air-bearing displacement sensor are described. Then, in order to identify the basic performance of the sensor, a measuring force and displacement output of the sensor are evaluated on a vibration isolated table. The sensor is also mounted on a diamond turning machine to evaluate the surface form of micro structures. A roll workpiece with Ni-P plating surface, on which micro-lens array are fabricated by using a FS-FTS (Force sensor fast tool servo) on the machine tool, is employed as a specimen for measurement. © 2012 IEEE.
  • Yuki Shimizu, Sungho Jang, Takemi Asai, So Ito, Wei Gao
    2012 IEEE I2MTC - International Instrumentation and Measurement Technology Conference, Proceedings 2012年07月 
    In this paper, a scanning-light method is proposed to evaluate the form of the tool cutting edge in a wide range up to several millimeters. An optical system, which consists of a photo diode, a laser diode unit and an objective lens, was developed. A small laser spot generated by the objective lens scans across the tool cutting edge, while monitoring the intensity of the laser beam passed through the tool cutting edge. In the proposed method, variation of the detected intensity is converted into information of the measured tool form. Feasibility of the proposed method was confirmed by simulations and experiments. © 2012 IEEE.
  • 後藤成晶, 清水裕樹, LEE JungChul, 伊東聡, GAO Wei, 足立茂, 大宮恭平, 佐藤広規, 久田哲弥, 齋藤佳史, 久保田浩明
    精密工学会誌 2012年07月
  • Design of a Micro-sized Thermal Contact Sensor for Inspection of Surface Defects  [通常講演]
    Yuki Shimizu, Wenjian Lu, Wei Gao
    3rd International Conference on Nanomanufacturing (nanoMan2012) 2012年07月 口頭発表(招待・特別) 日本国 Wako
  • A scanning-light method for inspection of tool cutting edge  [通常講演]
    Yuki Shimizu, SungHo Jang, Takemi Asai, So Ito, Wei Gao
    2012 IEEE International Instrumentation and Measurement Technology Conference 2012年05月 ポスター発表 ドイツ Graz
  • ヘッド組み込み型熱検知センサを用いた磁気ディスク表面のナノ微小欠陥検出技術  [通常講演]
    清水 裕樹, 徐 鈞国, 小平英一
    トライボロジー会議 2012 春 2012年05月 口頭発表(招待・特別) 日本国 TOKYO
  • 東豊大, 丹羽英二, PENG Yuxin, 金子純史, 清水裕樹, 伊東聡, GAO Wei
    日本機械学会東北支部総会・講演会講演論文集 2012年03月
  • JANG SungHo, 清水裕樹, 伊東聡, GAO Wei
    日本機械学会東北支部総会・講演会講演論文集 2012年03月
  • 細野幸治, KIM Woojae, 清水裕樹, 伊東聡, GAO Wei
    精密工学会大会学術講演会講演論文集 2012年03月
  • 後藤成晶, 細渕啓一郎, 伊東聡, 清水裕樹, GAO Wei
    精密工学会大会学術講演会講演論文集 2012年03月
  • 武藤啓志, 後藤成晶, 細野幸治, 清水裕樹, GAO Wei, 足立茂, 大宮恭平, 佐藤広規, 久田哲弥, 齋藤佳史, 久保田浩明
    精密工学会大会学術講演会講演論文集 2012年03月
  • 武石俊希, BIN Xu, 伊東聡, 清水裕樹, GAO Wei, 山崎宏, 中沢芳司
    精密工学会大会学術講演会講演論文集 2012年03月
  • 清水 裕樹, 盧 文剣, 東 豊大, 高 偉
    精密工学会2012年度春季講演会 2012年03月 口頭発表(一般) 日本国 TOKYO
  • 李 康源, 伊東 聡, 清水 裕樹, 高 偉
    東北支部総会・講演会 講演論文集 2012年
  • 李 貞徹, 清水 祐樹, 伊東 聡, 高 偉, HWANG Jooho, OH JeongSeok, PARK ChunHong
    東北支部総会・講演会 講演論文集 2012年
  • 張 城豪, 清水 裕樹, 伊東 聡, 高 偉
    東北支部総会・講演会 講演論文集 2012年
  • 盧 文剣, 清水 裕樹, 大場 裕太, 高 偉
    生産加工・工作機械部門講演会 : 生産と加工に関する学術講演会 2012年 
    Experimental study on a thermal contact sensor for the detection of defects on smooth surfaces is described. As a prototype of the thermal contact sensor, a several-ten-micrometer-sized thin-film element was fabricated by photolithography processes. By using the fabricated element, both laser exposure tests and friction tests were carried out to investigate the feasibility of the element on detecting small amount of frictional heats. Three types of sensors with the element of different sizes are employed to compare the temperature rises due to the heating. Results of theoretical calculations are also compared with the experimental results to confirm the feasibility of the contact sensor.
  • 李 貞徹, 清水 裕樹, 伊東 聡, 高 偉, Chun Hong Park, Jooho Hwang, Jeoung Seok Oh
    生産加工・工作機械部門講演会 : 生産と加工に関する学術講演会 2012年 
    This paper presents the on-machine surface form evaluation of a large-scale roll workpiece on a drum roll lathe. In this research, the surface form of a large-scale roll workpiece, which is composed of the out-of-straightness, the out-of-roundness and the differences of the diameter along the axial direction of a large-scale roll workpiece, is measured by using two capacitive type displacement probes placed on the two sides of a large-scale roll workpiece
  • Surface characterization of a diamond turned XY sinusoidal grating  [通常講演]
    Yuki Shimizu, Shinichi Osawa, Takayuki Meguro, Wenjian Lu, Wei Gao
    1st CIRP Conference on Surface Integrity (CSI) 2012年01月 ポスター発表 ドイツ Bremen
  • Shinichi Osawa, Yuki Shimizu, Wei Gao, Tsutomu Fukuda, Akira Kato, Kouji Kubota
    Proceedings of the 6th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2011 2011年12月 
    This paper presents a high speed and a high accurate measurement method for the height of the cutting edge of a rotary cutting tool with respect to the reference surface on the tool by using a laser displacement sensor. In this method, the height of the cutting edge is obtained from the output of the optical displacement sensor when the intensity output reaches the maximum. Both simulation and experimental results confirmed that the proposed method enables us to measure the height of cutting edge, the width of which is smaller than that of the laser spot.
  • Toshiki Takeishi, Xu Bin, Yuki Shimizu, Wei Gao
    Proceedings of the 6th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2011 2011年12月 
    This paper presents precision measurement of a micro-part which has micro-structured surfaces. Micro-parts sometimes have short pitches and large amplitudes. Measurements are conducted by the use of conventional measuring instruments and found that these instruments are difficult to measure their profiles. A novel measuring system is presented which uses a contact-type displacement sensor, probe shaft of which is levitated by air-bearings to reduce the contact force. After developing the new measuring system, measurement and analysis results are shown. Wavelet analysis reveals that there are errors in the measurement results and they are caused by stylus jump.
  • Takayuki Meguro, Yuki Shimizu, Wei Gao
    Proceedings of the 6th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2011 2011年12月 
    This research describes an angle sensor based on laser autocollimation, with a laser rangefinder which is based on the principle of phase-difference distance measurement using a pulsed light source. The angle sensor and the laser rangefinder are combined with each other by sharing the same laser source for simultaneous measurement of the moving distance and two-axis tilt angles of a target mirror. A prototype sensor was fabricated and the evaluation experiment was conducted. Experimental results have shown that the sensor has a resolution of 1 mm for distance measurement and a resolution of 0.1 arc-seconds for tilt angle measurements.
  • Bin Xu, Yuki Shimizu, Wei Gao
    Proceedings of SPIE - The International Society for Optical Engineering 2011年12月 
    This paper presents a micro-stylus probe, which is composed of a precision glass micro-ball and a shaft made by a glass tube. The diameter of the micro-ball was 50 μm. The tip angle of the glass-tube shaft was approximately 10 degrees. Strength test shows that the tolerance of glass tube micro-stylus against external forces is 90 mN. To reduce the stick-slip phenomena, a micro-tapping probe employing the glass tube micro-stylus and a PZT actuator was demonstrated. The micro-stylus probe was mounted to an air-bearing displacement sensor for scanning surface form metrology. Experimental results showed that the micro-tapping probe was effective for reducing the influence of the stick-slip phenomena. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).
  • Yuxin Peng, Yasumasa Sakurai, Yoshikazu Arai, Yuki Shimizu, Wei Gao
    Proceedings of SPIE - The International Society for Optical Engineering 2011年12月 
    This paper presents a linear-rotary micro-stage that can generate motions along and about the Z-axis using piezoelectric elements (PZTs). The small stroke of a PZT is extended by repeating the PZT motions based on a mechanism of impact friction drive. The friction drive mechanism has a simple driving unit, which only consists of a PZT element and a friction element. The moving element of the stage, which is a steel cylinder, is supported and actuated by a driving unit, which consists of two PZTs and a friction component made by permanent magnet. The magnetic force is employed for holding the moving element and stabilizing the driving condition. The dimension of the stage is 7.0 mm x 8.8 mm x 7.5 mm. The moving ranges of the stage are about 5.0 mm in the Z-direction and 360 degrees in the θ z -direction, respectively. The maximum moving speeds are approximately 30 mm/s and 84 rpm in the two directions, respectively. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).
  • Surface Encoders forPrecision Measurement of Multi-axis Motions  [通常講演]
    Wei GAO, Yuki SHIMIZU, So Ito,WoojaeKim, Akihide Kimura, KoujiHosono
    4th International Conference of Asian Society for Precision Engineeringand Nanoechnology (ASPEN2011) 2011年11月 口頭発表(招待・特別) 中国 HongKong
  • 後藤成晶, LEE Jung Chul, 清水裕樹, GAO Wei, 足立茂, 大宮恭平, 佐藤広規, 久田哲弥, 齋藤佳史, 久保田浩明
    精密工学会大会学術講演会講演論文集 2011年09月
  • Spindle error motion measurement of a large-scale ultra-precision lathe  [通常講演]
    李 貞徹, 清水 裕樹, 高 偉, ChunHong Park, Jooho Hwang, JeongSeok Oh
    精密工学会2011年度秋季講演会 2011年09月 口頭発表(一般) 日本国 Kanazawa
  • AN OVERVIEW OF PRECISION MEASUREMENT TECHNOLOGY IN HEAD-DISK INTERFACE IN HARD DISK DRIVES  [通常講演]
    Yuki Shimizu
    The 7th International Symposium on Precision Engineering Measurements and Instrumentation (ISPEMI2011) 2011年08月 口頭発表(招待・特別) 中国 Lijiang
  • Nano-scale defect mapping on a magnetic disk surface using contact sensor  [通常講演]
    清水裕樹
    (社)日本トライボロジー学会 第3種研究会 「ファイル記憶のトライボロジー」 2011年07月 口頭発表(招待・特別) 日本国 TOKYO
  • Nano-scale defect mapping on a magnetic disk surface using contact sensor  [通常講演]
    Yuki Shimizu, Hidekazu Kohira
    2011International Magnetics Conference(INTERMAG) Taipei 2011年04月 口頭発表(招待・特別) 台湾 Taipei
  • Y. Shimizu, S. Osawa, T. Meguro, W. Lu, W. Gao
    Procedia Engineering 2011年01月 
    Surface characterization of an XY sinusoidal grating, which is fabricated by FTS (fast tool servo) on a diamond turning machine, is presented. The grating has a three dimensional micro-structured surface, which is a superposition of sinusoidal waves in the X- and Y-direction. The pitches and amplitudes of the sine waves are 10 ?m and 0.4 ?m, respectively. The surface form of the grating is imaged by a confocal microscope, a white light interference microscope and an atomic force microscope. The 3D images from the microscopes are compared with each other to distinguish the measurement uncertainties. The microscope images are analyzed by the two-dimensional discrete Fourier transform technique, which perfectly matches the nature of sinusoidal waves. The spatial spectrum of the grating surface is employed to identify the specific error factors introduced in the diamond turning process. © 2012 Published by Elsevier Ltd. Selection and peer-review under responsibility of Prof. E. Brinksmeier.
  • J. Xu, Y. Shimizu, H. Matsumoto, K. Matsuda
    Digest of the Asia-Pacific Magnetic Recording Conference 2010, APMRC 2010 2010年12月 
    Study of lubricant coated slider showed that low slide surface energy has significant advantages in stable slider flying and less lubricant droplet formation on the disk surface at ultra-narrow clearance. Drive level evaluation showed the lubricant pick-up induced flying height increase is as one fifth low as control slider.
  • 磁気ヘッドのナノ隙間浮上制御技術を用いた極低浮上領域における磁気ヘッド挙動の実験的検討  [通常講演]
    清水裕樹
    (社)日本トライボロジー学会 第3種研究会 「ファイル記憶のトライボロジー」 2010年08月 口頭発表(招待・特別) 日本国 TOKYO
  • Jianhua Li, Junguo Xu, Yuki Shimizu, Masayuki Honchi, Kyosuke Ono
    Proceedings of the ASME/STLE International Joint Tribology Conference 2009, IJTC2009 2010年06月 
    Small perturbation and modal-analysis methods were employed to systematically study a damped slider's dynamic characteristics. We found that a design with grooves distributed on a trailing pad effectively improved the slider's damping at higher frequencies, and the damping ratio was dependent on the number of grooves, their depth, location, width, length, distribution, orientation, and types. A higher damping ratio could be obtained by optimizing these parameters. The femto slider with distributed damping grooves on a trailing pad had a higher damping ratio in the third mode, and hence, its responses to disk parallel and wavy motion were greatly reduced. This new design for the damped slider was an effective solution reducing the slider's modulation. © 2009 by ASME.
  • EXPERIMENTAL STUDY ON SLIDER DYNAMICS DURING TOUCHDOWN BY USING THERMAL FLYING-HEIGHT CONTROL  [通常講演]
    Yuki Shimizu, Junguo Xu, Hidekazu Kohira, Kenji Kuroki, Kyosuke Ono
    The 20th ASME Information Storage and Processing Systems Conference 2010年05月 口頭発表(一般) アメリカ合衆国 Santa Clara, California
  • Hui Li, Jianhua Li, Junguo Xu, Yuki Shimizu, Kyosuke Ono, Shinobu Yoshida
    2008 Proceedings of the STLE/ASME International Joint Tribology Conference, IJTC 2008 2009年10月 
    This work carries on a numerical simulation of the touchdown/takeoff (TD/TO) hysterisis of the spherical pad slider. It numerically studies the meniscus bridge's formation and meniscus force interaction between the spherical pad and lubricant over the disk surface. It proposes a geometry model for the lubricant bridge, and correspondingly, a force model for the meniscus force acting on the spherical pad slider due to the lubricant bridge. By solving the liquid balance state at the meniscus boundary, it obtains the geometry of the liquid bridge. A parametric study is done to study the effects of the geometry of spherical pad, Hamaker constant of lubricant-disk, and surface energy of lubricant on the formation of the liquid bridge. The overflow phenomenon is analyzed to find out the acceptable dimension of the spherical pad design. Moreover, a three-dimensional (3D) model of spherical pad slider/disk interface is built to study the steady-state flying of the spherical pad slider. The different parameters are analyzed to study their effects on the TD/TO hysteresis. Copyright © 2008 by ASME.
  • “DAMPING SLIDER” AIR-BEARING DESIGN CONCEPTS AND SLIDER DEVELOPMENT  [通常講演]
    Yuki SHIMIZU, Junguo XU, Jianhua LI, Kyosuke ONO
    2009 JSME/IIP/ASME/ISPS Joint Conference on Micromechatronics for Information (MIPE2009) 2009年06月 口頭発表(一般) 日本国 Tsukuba
  • Experimental and Numerical Simulation Study on Low-Surface Energy Slider With Thermal Flying-Height Control Function  [通常講演]
    Yuki Shimizu, Kyosuke Ono, Noritsugu Umehara, Junguo Xu
    2009 International Magnetics Conference (Intermag2009) 2009年05月 口頭発表(一般) アメリカ合衆国 Sacrament, California
  • Fluorine-ion-implanted Air-bearing Surface for Low-friction Head-disk Interface  [通常講演]
    Yuki Shimizu, Noritsugu Umehara, Junguo Xu
    The 18th ASME Information Storage and Processing Systems Conference 2008年06月 口頭発表(一般) アメリカ合衆国 Santa Clara, California
  • A Spherical-Pad Head Slider for Stable Low-Clearance Recording  [通常講演]
    Yuki Shimizu, Kyosuke Ono, Junguo Xu, Ryuji Tsuchiyama, Hidetoshi Anan
    The 18th ASME Information Storage and Processing Systems Conference 2008年06月 口頭発表(一般) アメリカ合衆国 Santa Clara, California
  • Jianhua Li, Junguo Xu, Yuki Shimizu
    Proceedings of STLE/ASME International Joint Tribology Conference, IJTC 2006 2006年11月 
    A simulation method, in which grooves are virtually distributed on the slider air-bearing surface instead of on grooved medium surface, is developed to investigate slider flying ability fundamentally. Its feasibility is verified. The characteristics of a slider flying over a discrete track medium (DTM) surface are simulated, including the flying attitude, groove parameters effect on flying profile, 3 a flying height, and flying height sensitivity on altitude of the slider. Simulation results indicate that when a traditional slider is flying over a DTM surface, it will have a higher 3 sigma of flying height, a more sensitivity on altitude, and a bigger flying height loss. Copyright © 2006 by ASME.
  • リードバック信号を利用した磁気ヘッドスライダ浮上変動測定装置の開発  [通常講演]
    清水裕樹, 徐鈞国
    トライボロジー会議 2005 秋 2006年09月 口頭発表(一般) 日本国 TOKYO
  • 磁気ヘッド浮上面の機能性表面化によるナノ隙間浮上磁気ヘッドの安定性向上  [通常講演]
    清水裕樹
    (社)日本トライボロジー学会 第3種研究会 「ファイル記憶のトライボロジー」 2006年09月 口頭発表(招待・特別) 日本国 TOKYO
  • Air-bearing surface chemical modification for low-friction head-disk interface  [通常講演]
    Yuki Shimizu, Junguo Xu, Shozo Saegusa, Noritsugu Umehara
    ASME/JSME Joint Conference on Micromechatronics for Information and Precision Equipment (MIPE 2006) 2006年06月 口頭発表(一般) アメリカ合衆国 Santa Clara, California
  • Two-Dimensional Flying-Height Modulation Mapping at HDD Drive Level  [通常講演]
    Yuki Shimizu, Junguo Xu
    2006 International Magnetics Conference (Intermag2006) 2006年05月 口頭発表(一般) アメリカ合衆国 San Diego, California
  • 清水裕樹, 高偉, 清野慧
    精密工学会大会学術講演会講演論文集 2002年03月
  • 清水 裕樹, 高 偉, 清野 慧
    精密工学会大会学術講演会講演論文集 2002年03月
  • 清野慧, 清水裕樹, 星野唯, 高偉
    精密工学会大会学術講演会講演論文集 2000年03月
  • 清野 慧, 清水 裕樹, 星野 唯, 高 偉
    精密工学会大会学術講演会講演論文集 2000年03月

その他活動・業績

特許

受賞

  • 2022年03月 公益社団法人 精密工学会 精密工学会論文賞
     An absolute surface encoder with a planar scale grating of variable periods 
    受賞者: 清水 裕樹;石塚 稜;真野 和樹;神田 悠利;松隈 啓;高 偉
  • 2021年12月 一般財団法人FA財団 FA財団論文賞
     大面積2軸スケール格子製作のための非直交型2軸ロイドミラー干渉計の最適化設計 
    受賞者: Yuki Shimizu;Kazuki Mano;Hiroki Murakami;Shunsuke Hirota;Hiraku Matsukuma;Wei Gao
  • 2021年03月 公益社団法人 精密工学会 精密工学会沼田記念論文賞
     Design optimization of a non-orthogonal two-axis Lloyd's mirror interferometer for fabrication of large-area two-dimensional scale gratings 
    受賞者: 清水裕樹;真野和樹;村上裕記;廣田駿介;松隈啓;高偉
  • 2019年03月 公益社団法人精密工学会 精密工学会沼田記念論文賞
     Design and testing of a compact non-orthogonal two-axis Lloyd's mirror interferometer for fabrication of large-area two-dimensional scale grating 
    受賞者: 清水 裕樹;相原 涼;真野 和樹;Chong Chen;Yuan-Liu Chen;Xiuguo Chen;高 偉
  • 2018年11月 IEEE 2018 International Conference on Advanced Manufacturing Best Conference Paper Award
     Theoretical calculation of the reading output from a micro thermal sensor for precision positioning 
    受賞者: Yuki Shimizu;Ayaka Ishida;Hiraku Matsukuma;Wei Gao
  • 2018年06月 公益財団法人 工作機械技術振興財団 工作機械技術振興賞(論文賞)
     An optical lever by using a mode-locked laser for angle measurement 
    受賞者: 清水 裕樹;工藤 幸利;陳 遠流;伊東 聡;高 偉
  • 2018年05月 一般財団法人みやぎ産業科学振興基金 みやぎ産業科学振興基金研究奨励賞
     国家標準にダイレクトにリンクした超高精度・高安定精密角度計測に関する研究 
    受賞者: 清水 裕樹
  • 2018年03月 公益社団法人精密工学会 精密工学会論文賞
     An optical lever by using a mode-locked laser for angle measurement 
    受賞者: 清水 裕樹;工藤 幸利;陳 遠流;伊東 聡;高 偉
  • 2017年11月 一般社団法人 日本機械学会 生産加工・工作機械部門 一般社団法人 日本機械学会 生産加工・工作機械部門 優秀講演論文表彰
     Ultra-precision angle sensor with a mode-locked laser source 
    受賞者: Shuhei MADOKORO;Yuki SHIMIZU;Yuan-Liu CHEN;Wei GAO
  • 2017年11月 The conference Committee of CJUMP2017 The 13th China-Japan International Conference on Ultra-Precision Machining Process (CJUMP2017) Best Paper Award
     
    受賞者: Bo Wen;Yuan-Liu Chen;Yuki Shimizu;Wei Gao
  • 2017年09月 The conference Committee of ISMTII2017 13th International Symposium on Measurement Technology and Intelligent Instruments 2017 Xi’an (ISMTII2017) Best Paper Award
     Non-contact detection of surface defects by using a micro thermal sensor 
    受賞者: Yuki Shimizu;Yuki Matsuno;Yuan-Liu Chen;Wei Gao
  • 2016年08月 The conference Committee of nanoMan2016 The 5th International Conference on Nanomanufacturing (nanoMan2016) Best Pawer Award
     Spindle Error Motion Measurement of Concentricity Gage by Using Laser Scan Micrometer 
    受賞者: Zengyuan Niu;Yuki Shimizu;So Ito;Wei Gao
  • 2016年04月 文部科学省 科学技術分野の文部科学大臣表彰 若手科学者賞
     微空間での熱収支と光を応用した超精密ナノ形状計測の研究 
    受賞者: 清水裕樹
  • 2015年11月 The Editorial and Review Committee of the 11th CJUMP Excellent Paper Award
     Investigation of the Deformation Mechanism of a Copper Workpiece during Nanoindentation by using Molecular Dynamics 
    受賞者: Yindi Cai;Yuanliu Chen;Yuki Shimizu;So Ito;Wei Gao
  • 2015年11月 The Editorial and Review Committee of the 11th CJUMP The 11th China-Japan International Conference on Ultra-Precision Machining Process (CJUMP2015) Excellent Paper Award
     Precision Measurement of Slide Straightness of an Ultra-Precision Lathe 
    受賞者: Zengyuan Niu;Yuanliu Chen;Daiki Matsuura;Ryo Kobayashi;Yuki Shimizu;So Ito;Wei Gao
  • 2015年06月 公益財団法人工作機械技術振興財団 工作機械技術振興賞・論文賞
     Development of an optical probe for evaluation of tool edge geometry 
    受賞者: 張 城豪;清水 裕樹;伊東 聡;高 偉
  • 2014年09月 International Measurement Confederation (IMEKO) Technical Committee TC14 Excellent Paper Award
     Design of an optical system for evaluation of edge contour of a diamond cutting tool 
    受賞者: Y. Shimizu;S. Jang;W. Gao
  • 2013年11月 Asian Society for Precision Engineering and Nanotechnology ASPEN Young Researcher Award
     
    受賞者: Yuki Shimizu
  • 2012年07月 International Society of Nanomanufacturing Excellent Presentation Award
     Design of a Micro-sized Thermal Contact Sensor for Inspection of Surface Defects 
    受賞者: 清水 裕樹
  • 2012年05月 一般社団法人日本トライボロジー学会 日本トライボロジー学会 2011年度日本トライボロジー学会技術賞
     ヘッド組み込み型熱検知センサを用いた磁気ディスク表面のナノ微小欠陥検出技術 
    受賞者: 清水裕樹;徐 鈞国;小平英一
  • 2010年08月 ASME Information Storage and Processing Systems (ISPS) Division ASME ISPS2010 Best Conference Industry Paper Award
     
    受賞者: Yuki SHIMIZU;Junguo XU;Hidekazu Kohira;Kenji Kuroki;Kyosuke ONO
  • 2009年04月 社団法人日本機械学会 2009年 日本機械学会奨励賞 (技術)
  • 2003年03月 社団法人精密工学会 2002年度精密工学会沼田記念論文賞
     
    受賞者: 高 偉;星野 唯;清水 裕樹;清野 慧
  • 2000年12月 社団法人精密工学会 精密工学会東北支部2000年度支部講演会 優秀講演奨励賞

共同研究・競争的資金等の研究課題

  • 光コム次元変換光学とその場自律校正法の創出によるサブアトム級3次元超精密計測
    日本学術振興会:科学研究費助成事業 基盤研究(A)
    研究期間 : 2020年04月 -2024年03月 
    代表者 : 高 偉, 清水 裕樹, 松隈 啓
  • 次世代「つながる」超精密光計測学構築への挑戦
    国立研究開発法人 科学技術振興機構:JST 創発的研究支援事業
    研究期間 : 2021年04月 -2024年03月 
    代表者 : 清水裕樹
  • 透過フェムト秒レーザ熱検知プローブによる非接触・非破壊サブサーフェス評価への挑戦
    日本学術振興会:科学研究費助成事業 挑戦的研究(萌芽)
    研究期間 : 2020年07月 -2023年03月 
    代表者 : 清水 裕樹
  • 次元変換型マルチビーム角度センサでの多元情報一括検出による次世代光学素子形状計測
    日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2018年04月 -2021年03月 
    代表者 : 清水 裕樹
     
    本研究では,次世代半導体露光装置向けX線光学素子などに要求される超精密形状精度実現に必須となる超精密光学自由曲面形状計測技術確立を目的として,フェムト秒レーザと分光素子で生成する多元情報マルチビームを光源として用い,空間領域で一括捕捉した反射光群から周波数領域において各ビーム固有の光周波数をもとにビーム位置および局所的傾斜角情報(スロープマップ)を抽出する,「次元変換型マルチビーム角度センサ」を用いた新たな光学自由曲面形状計測原理を提案する.傾斜角およびビーム位置という空間領域の多元情報を周波数領域で一括取得する,これまでにない発想に基づく高速でロバストな計測原理の確立により,ビーム走査不要の光学自由曲面形状計測を実現し,測定不確かさを極限まで低減することを目的としている. 計画2年目である令和元年度は,前年度に引き続き主に【TaskⅠ】フェムト秒レーザと分光素子による多元情報マルチビーム生成手法の確立,および【TaskⅡ】次元変換型マルチビーム角度センサ光学系の最適化設計 に取り組んだ.【Task I】では,前年度構築のフェムト秒レーザ光源光学系に,コリメート光入射型マルチビーム生成光学系を組み合わせたプロトタイプ光学系を構築し,生成したマルチビームをビームプロファイラを用いて評価した.また【TaskⅡ】では,シングルモードファイバと光スペクトラムアナライザで構成した受光ユニットを有する光学式角度センサ光学系で実現可能な測定分解能および測定レンジを検討した.マルチビームを平面ミラー試料に入射し,得られた反射光群を光ファイバ受光ユニットで一括取得して光スペクトラムアナライザで周波数領域に次元変換し,ビーム固有の光周波数をもとに各ビームからの位置・姿勢角情報(スロープマップ)抽出を試み,構築した光学系で平面ミラーの角度変位が検出可能なことを実験的に明らかにした.
  • 日本学術振興会:科学研究費助成事業 挑戦的研究(萌芽)
    研究期間 : 2018年06月 -2020年03月 
    代表者 : 清水 裕樹
     
    自己ジュール発熱により微小間隙に安定熱収支場を生成してその変化を高精度に検知するマイクロ熱検知素子を用い,高精度マイクロパターン(スケール)の3次元形状を読み取ることで,超コンパクトな形態での高精度・多軸変位計測を実現する「マイクロ熱収支場検知式エンコーダ」の基礎原理を提案した.フォトリソグラフィプロセスを用いてガラス基板上にマイクロ熱検知素子を試作し,マイクロパターン群を有する回折格子と組み合わせてマイクロ熱収支場検知式エンコーダのプロトタイプを構築して原理検証実験を行い,その実現可能性を実験的に明らかにした.
  • 日本学術振興会:科学研究費助成事業 基盤研究(S)
    研究期間 : 2015年05月 -2020年03月 
    代表者 : 高 偉, 清水 裕樹, 松隈 啓, 陳 遠流, 伊東 聡
     
    超精密光計測学のフロンティア開拓を目的として,2軸光ナノグリッドと光絶対周波数コムを融合した多軸光絶対スケールコムを開発した.干渉グリッド定在波生成光学系を構築し,100mm四方の大面積に渡るサブμmピッチのナノグリッドを一括露光するとともに,そのZ平面度,XYピッチ誤差の一括自律校正法を確立した.さらに,ナノグリッドの分光機能をもとに光コム光源を光絶対スケールコムに変換する新理論を確立した.
  • 超高精度ナノグリッド基準と光絶対スケールコムの創出が拓く精密光計測フロンティア
    科学研究費補助金
    研究期間 : 2015年04月 -2020年03月
  • 次世代の超精密ナノ計測を実現する光ナノグリッド基準の自律校正
    日本学術振興会:科学研究費助成事業 特別研究員奨励費
    研究期間 : 2016年11月 -2019年03月 
    代表者 : 清水 裕樹, CHEN XIUGUO
     
    本研究では,次世代の超精密ナノ計測を実現する光ナノグリッド基準の自律校正の実現を目的とし,XYナノグリッド定在波を高安定ガラス基板レジスト層に露光して,サブマイクロメートルピッチ正弦波光ナノグリッド基準を製作する手法を検討する.レーザ波面を三つに分割して干渉させてXY ナノグリッド定在波を生成するための波面分割光学系に,XYビーム干渉による定在波の歪成分を解消するための偏光変調制御法を組み合わせて定在波を生成する.また,この生成定在波をガラス基板上に構成した薄膜レジスト層に露光してナノグリッドパターンを構成する.さらに,作成したナノグリッドについて,複数のグリッド回折光波面から校正基準を自律的に創製するという,自律校正の新原理によって,光ナノグリッド基準と評価用干渉形状測定機の誤差成分を分離して求める手法を検討する. 2年目となる29年度は,当初の予定どおりに,前年度に試作した光干渉グリッド定在波転写システムの基礎特性に関する実験的検証を進めるとともに,複数のグリッド回折光波面から校正基準を自律的に創製する自律校正の新原理によって,光ナノグリッド基準と評価用干渉形状測定機の誤差成分を分離して求める手法を検討した.新原理に基づく光ナノグリッド基準の評価アルゴリズムを構築し,計算機シミュレーションによりその妥当性を評価するとともに,自律校正システムのプロトタイプを構築し,実験的にもその妥当性を評価した.複数の1次回折光波面を測定するために,研究室で所有の光学式干渉形状測定機をベースとして,光ナノグリッド基準を測定機の光軸に合わせて回転する機構を有する実験装置を構築し,前述の光干渉グリッド定在波転写システムで創成した光ナノグリッド基準を自律校正し,そのZ平面度とXYピッチ誤差及び干渉形状測定機の参照鏡誤差を分離して求められることを実験的に実証した.
  • 日本学術振興会:科学研究費助成事業 国際共同研究加速基金(国際共同研究強化)
    研究期間 : 2017年 -2019年 
    代表者 : 清水 裕樹
     
    本共同研究では,基課題で検討中のマイクロ熱検知素子による微小欠陥検出の高精度化実現に向け,熱検知素子-測定面間の間隙量検出技術の開発を目的として,モード同期フェムト秒レーザを光源に用いた2面間高精度変位検出技術について検討するとともに,パルスレーザ周波数安定制御システムの開発を試みた.また,熱検知素子でスケール目盛を読み取り位置検出する,全く新たな原理に基づく「熱収支場検知式リニアスケール」の実現に必須となる,素子-測定面間隙のチルト検出手法の確立を目指し,光学式角度センサ技術に立脚したチルト検出手法を開発した.
  • 日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2015年04月 -2018年03月 
    代表者 : 清水 裕樹
     
    半導体/LED向けウエハなどの次世代ナノ平滑面に要求される微小欠陥の高精度検出実現に向けて,ナノ熱収支場を利用した全く新しい非接触欠陥検出原理を提案した.薄膜抵抗体からなるナノ熱収支場生成素子を試作して高感度な熱収支場の変動検知を実現するとともに,プローブ先端変位・チルト検出機能を有するナノ間隙プローブを構築した.さらに,素子-測定面間の接触を高感度に検知して素子-測定面間に安定したナノ間隙を生成する手法を確立するとともに,素子-測定面間のせん断方向に相対変位を与えた際の素子出力変動をモニタすることで,非接触状態で測定面上の凹凸形状を高感度に検出できることを実験的に明らかにした.
  • 日本学術振興会:科学研究費助成事業 挑戦的萌芽研究
    研究期間 : 2015年04月 -2017年03月 
    代表者 : 清水 裕樹, 高 偉
     
    次世代精密切削工具の高精度刃先形状定量評価実現を目的として,集光レーザービーム(レーザプローブ)を利用した工具エッジ形状の非接触・高速評価技術の開発を試みた.高精度対物レンズを採用したレーザプローブ光学系を構築してその基礎特性を実験的に評価し,光の回折限界を超える高い測定分解能でのエッジ検出を実現した.また,レーザプローブでシングルポイントダイヤモンド工具刃先輪郭を走査して得られたプローブ出力から,刃先輪郭形状を高精度に評価できることを実験的に明らかにした.さらに,切れ刃稜丸みに沿ったレーザプローブ走査による切れ刃稜丸み径評価について原理検討及び実験的検討を試み,その実現可能性を明らかにした.
  • 日本学術振興会:科学研究費助成事業 挑戦的萌芽研究
    研究期間 : 2014年04月 -2016年03月 
    代表者 : 高 偉, 清水 裕樹
     
    本研究題目では,軟質金属表面に転写した単結晶ダイヤモンド切削工具マイクロ刃先の反転エッジの三次元精密形状測定より,マイクロエッジ絶対形状をサブナノメートルオーダーの超高精度で自律的に計測することを目的とした. 分子動力学(MD)シミュレーションに基づく原子スケールでの反転エッジ形成過程の最適化により,反転エッジ法を用いてサブナノメートルの超高精度三次元形状計測への有効性を示した.また工具運動と加工力を高分解能かつ高感度に測定可能な高感度加工力検出型工具サーボを構築し,提案手法の有効性について実験的な検証を実施した.
  • 日本学術振興会:科学研究費助成事業 若手研究(B)
    研究期間 : 2013年04月 -2015年03月 
    代表者 : 清水 裕樹
     
    半導体/LED 向けウエハ等の次世代ナノ平滑面に要求される微小欠陥の高精度検出実現に向けて,ナノ間隙での微小熱収支変化を利用した全く新しい欠陥検出原理を提案した.μWオーダの微小摩擦熱を高感度に検知するマイクロ熱検知素子を作成するプロセスを構築してプロトタイプ素子を設計・試作し,その基礎特性を評価した.検出対象との接触インパクト及び軽微な摩擦に伴い発生した微小熱を検知することで,先端径40 nmの接触子との接触を検知できることを実証するとともに,マイクロ熱検知素子-測定面間に温度勾配を設定して熱収支場を生成することで,摩擦熱に依らずに素子と欠陥との近接を検知できる可能性を実験的に明らかにした.
  • 日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2012年04月 -2015年03月 
    代表者 : 高 偉, 清水 裕樹, 伊東 聡
     
    サブnmの位置決め精度を有する次世代超精密ステージ実現のために,超精密移動ステージの動的3軸角度誤差が一括検出できる3軸レーザオートコリメータという多軸角度計測の新原理を提案した.各光学部品を50mmx30mmx30mmのコンパクトなサイズに収めた,リニアエンコーダとスケールを共有するマイクロ光学センサヘッドを設計・試作して,ロール,ヨー測定分解能0.01arcsecond,ピッチ分解能0.2arcsecondを実現した.更に,シングル素子フォトダイオードのエッジ効果を利用した超高感度光位置検出法を提案し,目標分解能である0.001arcscondを超える測定分解能が得られることを実証した.
  • 日本学術振興会:科学研究費助成事業 挑戦的萌芽研究
    研究期間 : 2012年04月 -2014年03月 
    代表者 : 高 偉, 清水 裕樹
     
    電荷を蓄えられるプローブ探針を用いて,大気中の水分が試料表面に凝着することで生成されるナノスケール厚さの水膜などから発生する静電気力遠接場を高速・高感度に可視化することで探針・試料表面間の絶対距離を自律的に計測する手法を提案し,高アスペクト比で複雑な構造を持つマイクロバイオオプティクス用金型などの微細形状を表面の電気的特性に影響されずに安定して非接触に高精度計測可能な静電気力遠接場走査プローブ顕微鏡を開発した.
  • 超精密加工用ダイヤモンド工具刃先のナノ・マイクロ摩耗定量評価技術の開発
    研究期間 : 2012年04月 -2014年03月
  • 熱検知接触型センサによるウェハ表面欠陥の高感度検出技術に関する研究
    科学研究費補助金
    研究期間 : 2011年02月 -2013年03月
  • 日本学術振興会:科学研究費助成事業 研究活動スタート支援
    研究期間 : 2011年 -2012年 
    代表者 : 清水 裕樹
     
    次世代ウエハ等のナノレベル平滑面に要求される微小欠陥検出実現を目的とし,軽微な接触で発生する極小摩擦熱を素子抵抗値変化に変換して微小突起を検出する,全く新しい欠陥検出コンセプトの確立に取り組んだ.有限要素モデル解析で提案コンセプト実現の可能性を見出すとともに,薄膜抵抗体からなるマイクロサイズの試作素子を用いた評価実験で,提案手法によるナノレベルサイズ微小欠陥検出実現の可能性を実験的に明らかにした.

大学運営

委員歴

  • 2021年04月 - 現在   日本機械学会   IIP部門 広報委員会委員長
  • 2021年04月 - 現在   日本トライボロジー学会   編集委員(司会幹事)
  • 2020年04月 - 2021年03月   日本機械学会   広報委員会副委員長
  • 2020年04月 - 2021年03月   日本トライボロジー学会   編集委員会
  • 2019年04月 - 2020年03月   日本機械学会   広報委員会幹事
  • 2016年04月 - 2018年03月   精密工学会東北支部   事業幹事
  • 2014年08月 - 2016年08月   砥粒加工学会   用語集改訂WG
  • 2014年04月 - 2016年03月   精密工学会東北支部   庶務幹事
  • 2012年04月 - 2015年03月   日本機械学会   会誌編修部会委員
  • 2012年08月 - 2014年07月   日本トライボロジー学会   研究委員会委員
  • 2012年04月 - 2014年03月   精密工学会東北支部   会計幹事
  • 2011年03月 - 2011年11月   ITC2011 Hiroshima   セッションオーガナイザー
  • 2011年08月   日本機械学会   東北支部第47期総会・講演会 実行委員
  • 2009年04月 - 2011年03月   日本トライボロジー学会   第3種研究会「ファイル記憶のトライボロジー」幹事

社会貢献活動

  • 夏休み子ども科学キャンパス
    期間 : 2014年07月30日 - 2014年07月31日
    役割 : その他 市内の小学校6年生を対象に,「不思議なうすい板で発電してみよう」と題して,簡単な電子工作を含む体験型学習教室の運営に講師として参加.
  • 夏休み子ども科学キャンパス
    期間 : 2013年07月30日 - 2013年07月31日
    役割 : その他 市内の小学校6年生を対象に,「君のアイディアでいろんなものを測ってみよう」と題して,鉄道線路等々,身近なものの形状をはかる体験型学習教室の運営に講師として参加.
  • 夏休み子ども科学キャンパス
    期間 : 2012年07月30日 - 2012年07月31日
    役割 : その他 市内の小学校6年生を対象に,「君のアイディアでいろんなものを測ってみよう」と題して,鉄道線路等々,身近なものの形状をはかる体験型学習教室の運営に講師として参加.

その他

  • 2016年03月 - 2016年03月  ミリメートル級の長ストローク駆動におけるナノレベル位置決めを実現する超精密3軸XYZマイクロステージの開発 
    医療・バイオテクノロジーや精密計測・加工の分野において要求される,限られたスペース内での精密位置決めの実現を目的として,従来比1/10のサイズを有するコンパクト(縦横サイズ25 mm×25 mm)なナノ位置決め用マイクロステージを開発する.永久磁石を用いた独自のステージプレート保持機構を適用するとともに,ステージ案内機構である微小板バネ表面に新たに直接形成する高感度Cr-Nひずみゲージを変位検出センサとして活用し,独創的なステージシステム構成とする.これにより,与圧機構等を必要としないコンパクトな形態での2軸フィードバック制御を可能とし,同サイズ従来品の10倍以上であるXY各軸方向ストローク1 mmを,位置決め分解能10 nmを維持したまま実現する.更に,2軸XYマイクロステージに新たにZ軸移動機構を付与した,3軸XYZマイクロステージの開発を試み,その有効性を実証するとともに,本提案手法のメカトロニクス技術への波及効果を狙う.
  • 2015年04月 - 2015年04月  次世代ナノ位置決めステージを実現する超精密姿勢計測センサの開発 
    本研究では,受光素子アクティブ制御を適用したレーザー角度センサによる,超高分解能(0.001"以上)・広測定レンジ(±1000")実現を目指す.受光素子アクティブ制御機構を含む1軸角度測定用プロトタイプ光学系を構築し,その有効性を実証する.
  • 2012年10月 - 2012年10月  超精密加工用ダイヤモンド工具刃先のナノ・マイクロ摩耗定量評価技術の開発 
    シングルポイントダイヤモンド切削工具による超精密加工について,更なる加工精度の向上を目指し,mmオーダの広いスケールに渡る,nmオーダ分解能の高速工具輪郭形状定量評価技術の確立に向けた研究開発に取り組む.


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