Researcher basic information

• https://researchmap.jp/yijun?lang=en

• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=202601018896745200
• https://orcid.org/0009-0007-1633-3917

• 91038728

• https://orcid.org/0009-0007-1633-3917

• 202601018896745200

Research activity information

• Reduction of appearance artifacts in wearable on-skin electronics
  Yijun Liu; Soutaro Ito; Takeo Kato; Liren Wang; Yicheng Zhu; Séverine De Mulatier; Hiroshi Arao; Shugo Suwazono; Hirotoshi Asano; Yuanyuan Zhou; Hinata Mitomo; Huimin Gong; Ohga Nomura; Gakuto Kagawa; Natsumi Watanabe; Mohammad H. Behfar; Yoshinori Kuroiwa; Tetsu Tatsuma; Yusuke Sugano; Hidetoshi Takahashi; Makoto Asai; Jiheong Kang; Naoji Matsuhisa
  Science Advances, 12, 29, American Association for the Advancement of Science (AAAS), 17 Jul. 2026, [Lead author]
  Scientific journal, Facial electrophysiological signals are crucial to human-machine interfaces and health care monitoring. Soft and skin-conformable electrodes enabled long-term and comfortable signal monitoring. However, the appearance of the electrodes affects the wearer’s social interactions and self-identity, making daily usage difficult and leaving appearance artifacts. Here, we developed fully invisible and unperceivable on-skin electrodes free from appearance artifacts. Neither the wearer nor observers can detect the visual and tactile presence of the electrodes on the skin. The unperceivable property was confirmed with sensory experiments and physical characterizations of the film on skin. Furthermore, our invisible electrodes did not affect the psychological conditions of the wearers, which confirms the feasibility of artifact-free monitoring in daily lives. Last, we demonstrated the functionality of our electrode with successful monitoring of various facial electrophysiological signals, including electrooculogram (EOG), electromyogram (EMG), and electroencephalogram (EEG). Our fully invisible electrodes provide a promising direction in developing on-skin bioelectronics, seamlessly integrating health monitoring and human-computer interaction technologies into people’s daily lives.
• Skin‐Like Tri‐Modal Sensors Based on Soft Piezoelectric and Ionic Composites
  Liren Wang; Peter Zalar; Vishva Bhate; Takeo Furukawa; Hidekazu Kodama; Yijun Liu; Yuanyuan Zhou; Chuang Hou; Siyuan Liu; Naoji Matsuhisa
  Advanced Materials Technologies, Wiley, 10 Mar. 2026
  Scientific journal, ABSTRACT
  
  Human skin perceives complex external stimuli through the coordinated detection of temperature, static strain, and dynamic strain. However, current skin‐like multimodal sensors are typically limited to dual‐mode sensing or suffer from signal interference and excessive wirings. In this study, a soft, skin‐like tri‐modal sensor capable of independent and simultaneous detection of temperature, static strain, and dynamic strain is reported. The sensor consists of a single, skin‐inspired sensing layer of a soft, piezoelectric and ionic composite film that is sandwiched between stretchable electrodes. It uses distinct frequency‐domain responses: charge relaxation time for temperature, normalized capacitance for static strain, and piezoelectric charge output for dynamic strain—to fully decouple signals without the need for separate sensors. Practical demonstrations include simultaneous detection of skin temperature and pulse waves at the wrist, localized mapping of strain and temperature under shear stress, and texture recognition through dynamic force sensing. This work provides a compact and scalable platform for fully decoupled tri‐modal sensing, paving the way for intelligent prosthetics, on‐skin electronics, and interactive robotics.
• Abrasion-resistant on-skin electrodes by high-toughness and skin-conformable elastomeric substrates
  Yijun Liu; Yicheng Zhu; Huimin Gong; Liren Wang; Jooyeun Chong; Jiheong Kang; Naoji Matsuhisa
  Applied Physics Express, 19, 3, 031001, 031001, IOP Publishing, 01 Mar. 2026, [Lead author]
  Scientific journal, Abstract
  
  Ultrathin, skin-conformal electrodes provide a secure, comfortable fit and enable continuous electrophysiological monitoring in daily lives. However, friction-induced damage from contact with skin or clothing made daily use difficult. Here, we demonstrate a facile fabrication of ultrathin on-skin electrodes robust against repeated mechanical friction. We identified that the mechanical toughness and skin-comformability are the key to realizing the high abrasion resistance to accommodate repeated deformation and redistribute frictional stresses. The abrasion-resistant skin-electrode was fabricated with a stretchable gold layer, and the feasibility was confirmed by the reliable acquisition of various electrophysiological signals.
• Fully invisible and unperceivable skin electrodes for facial physiological monitoring free from appearance artifacts
  Yijun Liu; Soutaro Ito; Takeo Kato; Liren Wang; Yicheng Zhu; Séverine De Mulatier; Hiroshi Arao; Shugo Suwazono; Hirotoshi Asano; Yuanyuan Zhou; Hinata Mitomo; Huimin Gong; Ohga Nomura; Gakuto Kagawa; Natsumi Watanabe; Mohammad H. Behfar; Yusuke Sugano; Hidetoshi Takahashi; Makoto Asai; Jiheong Kang; Naoji Matsuhisa
  American Chemical Society (ACS), 21 Aug. 2025, [Lead author]
• Unperceivable Designs of Wearable Electronics
  Yijun Liu; Séverine De Mulatier; Naoji Matsuhisa
  Advanced Materials, 37, 49, Wiley, 02 May 2025, [Lead author]
  Scientific journal, Abstract
  
  Wearable smart electronics are taking an increasing part of the consumer electronics market, with applications in advanced healthcare systems, entertainment, and Internet of Things. The advanced development of flexible, stretchable, and breathable electronic materials has paved the way to comfortable and long‐term wearables. However, these devices can affect the wearer's appearance and draw attention during use, which may impact the wearer's confidence and social interactions, making them difficult to wear on a daily basis. Apart from comfort, one key condition for user acceptance is that these new technologies seamlessly integrate into our daily lives, remaining unperceivable to others. In this review, strategies to minimize the visual impact of wearable devices and make them more suitable for daily use are discussed. These new devices focus on being unperceivable when worn and comfortable enough that users almost forget their presence, reducing psychological discomfort while maintaining accuracy in signal collection. Materials selection is crucial for developing long‐term and unperceivable wearable devices. Recent developments in these unperceivable electronic devices are also covered, including sensors, transistors, and displays, and mechanisms to achieve unperceivability are discussed. Finally, the potential applications are summarized and the remaining challenges and prospects are discussed.
• Intermediate State between MoSe₂ and Janus MoSeS during Atomic Substitution Process
  Hiroo Suzuki; Yijun Liu; Masaaki Misawa; Chiyu Nakano; Yingzhe Wang; Ryo Nakano; Kentaro Ishimura; Kenji Tsuruta; Yasuhiko Hayashi
  Nano Letters, 23, 10, 4533, 4540, American Chemical Society (ACS), 08 May 2023, [Lead author]
  Scientific journal
• Self-Limiting Growth of Monolayer Tungsten Disulfide Nanoribbons on Tungsten Oxide Nanowires
  Hiroo Suzuki; Misaki Kishibuchi; Masaaki Misawa; Kazuma Shimogami; Soya Ochiai; Takahiro Kokura; Yijun Liu; Ryoki Hashimoto; Zheng Liu; Kenji Tsuruta; Yasumitsu Miyata; Yasuhiko Hayashi
  ACS Nano, 17, 10, 9455, 9467, American Chemical Society (ACS), 01 May 2023
  Scientific journal
• Surface Diffusion-Limited Growth of Large and High-Quality Monolayer Transition Metal Dichalcogenides in Confined Space of Microreactor
  Hiroo Suzuki; Ryoki Hashimoto; Masaaki Misawa; Yijun Liu; Misaki Kishibuchi; Kentaro Ishimura; Kenji Tsuruta; Yasumitsu Miyata; Yasuhiko Hayashi
  ACS Nano, 16, 7, 11360, 11373, American Chemical Society (ACS), 06 Jul. 2022
  Scientific journal