Liquid-state optoelectronics

• Project/Area Number: 19K21942
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 20:Mechanical dynamics, robotics, and related fields
• Research Institution: Yokohama National University
• Principal Investigator: Ota Hiroki 横浜国立大学, 大学院工学研究院, 准教授 (30528435)
• Co-Investigator(Kenkyū-buntansha): 上野 和英 横浜国立大学, 大学院工学研究院, 准教授 (30637377)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000); Fiscal Year 2020: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2019: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
• Keywords: 液体金属 / 光エレクトロニクス / ストレッチャブルデバイス

Outline of Research at the Start

先進フレキシブル・ストレッチャブル(伸縮可能な)センサの一つとして液体金属とセンシングのためのイオン液体をからなるリキッドステート(Liquid state:LS)デバイスが提案されている。これは、従来のストレッチャブルセンサの欠点である感度と大変形の両立するデバイスである。しかし、これらセンサからシステムに昇華されるために必要な光エレクトロニクスに関するLSデバイスは実現していない。そこで本研究は光センサ・メモリに電気化学という新たな方法論を提案し、LS光デバイスを実現する。

Outline of Final Research Achievements

Liquid-state electronics utilizing functional liquids confined in soft templates as the sensing and actuating component present the ideal platform for enabling conformal coverage of electronic systems on curved and soft surfaces. However, to date, optoelectronic devices based on functional liquid materials as represented by photodetectors and optical memories still have not been proposed; this advancement is crucial to scaling up current liquid-state devices to a system level. Here, this study proposes optoelectronic devices based on liquid metal and photo-switchable ionic liquid with liquid-liquid heterojunction technology. The sensing and memory schemes we present are generic for different liquid-state devices, enabling different functionality to be added to the liquid-state electronics. As a proof of concept, we demonstrate a light sensor composed of the ionic liquid, and an optical memory using a composite of the ionic liquid and polypropylene glycol.

Academic Significance and Societal Importance of the Research Achievements

本研究の光エレクトロニクスは、従来の半導体材料に代わり液体材料を用いて電気化学的手法で実現する。本研究は新次元の柔軟性をもつ液体エレクトロニクスをシステムレベルまで昇華させるために重要な要素技術である。ゆえに当該分野の研究発展に大きな貢献をすることは明白である。特に、ウェアラブルデバイス、ロボティクスなど他分野でも液体金属デバイスの特性・高柔軟性を利用できる。学術的には液体エレクトロニクスに”光”という新たな物理対象を加えることができる。例えば液体金属表面にある極薄の酸化膜は自己修復機能を有する。そのため光制御を行うことで自己修復材料分野への学術的波及効果を期待することができる

Research Products

• [Journal Article] Transformable Electrocardiograph Using Robust Liquid?Solid Heteroconnector (2021)
  • Author(s): Takaya Maika、Matsuda Ryosuke、Inamori Go、Kamoto Umihiro、Isoda Yutaka、Tachibana Daiki、Nakamura Fumika、Fuchiwaki Ohmi、Okubo Yusuke、Ota Hiroki
  • Journal Title: ACS Sensors Volume: 6 Issue: 1 Pages: 212-219
  • DOI: 10.1021/acssensors.0c02135
  • Peer Reviewed / Open Access
• [Journal Article] Hydrogel Actuator with a Built-In Stimulator Using Liquid Metal for Local Control (2020)
  • Author(s): Ken Matsubara, Daiki Tachibana, Ryosuke Matsuda, Hiroaki Onoe, Ohmi Fuchiwaki, and Hiroki Ota
  • Journal Title: Advanced Intelligent Systems Volume: NA Issue: 5 Pages: 2000008-2000008
  • DOI: 10.1002/aisy.202000008
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Highly stretchable sensing array for independent detection of pressure and strain exploiting structural and resistive control (2020)
  • Author(s): Matsuda Ryosuke、Mizuguchi Satoru、Nakamura Fumika、Endo Takuma、Isoda Yutaka、Inamori Go、Ota Hiroki
  • Journal Title: Scientific Reports Volume: 10 Issue: 1 Pages: 1-9
  • DOI: 10.1038/s41598-020-69689-2
  • Peer Reviewed / Open Access
• [Journal Article] Liquid-State Optoelectronics Using Liquid Metal (2020)
  • Author(s): Takashi Kozaki, Satoshi Saito, Yota Otsuki, Ryosuke Matsuda, Yutaka Isoda, Takuma Endo, Fumika Nakamura, Takuto Araki, Taichi Furukawa, Shoji Maruo, Masayoshi Watanabe, Kazuhide Ueno, and Hiroki Ota
  • Journal Title: Advanced Electronic Materials Volume: NA Issue: 3 Pages: 1901135-1901135
  • DOI: 10.1002/aelm.201901135
  • Peer Reviewed / Int'l Joint Research
• [Presentation] Stretchable array of resistive pressure sensors ignoring the effect of strain-induced deformation. (2020)
  • Author(s): R. Matsuda, S. Mizuguchi, F. Nakamura, T. Endo, G. Inamori, Y. Isoda, H Ota
  • Organizer: 2020 IEEE 33nd International Conference on Micro Electro Mechanical Systems (MEMS)
  • Int'l Joint Research
• [Presentation] Highly deformable optoelectronics using liquid metal. (2020)
  • Author(s): T. Kozaki, S. Saito, Y. Otsuki, R. Matsuda, Y. Isoda, T. Endo, F. Nakamura, T. Araki, T. Furukawa, S. Maruo, M. Watanabe, K. Ueno, H. Ota
  • Organizer: 2020 IEEE 33nd International Conference on Micro Electro Mechanical Systems (MEMS)
  • Int'l Joint Research
• [Presentation] Electrically controlled gel actuator using liquid metal electrode. (2020)
  • Author(s): K. Matsubara, Y. Tanaka, O. Fuchiwaki, H. Ota
  • Organizer: 2020 IEEE 33nd International Conference on Micro Electro Mechanical Systems (MEMS)
  • Int'l Joint Research
• [Presentation] 誘導法に応じて変形するウェアラブル心電計の開発 (2020)
  • Author(s): 鷹屋 舞香, 稲森 豪, 磯田 豊, 中村 史香, 松田 涼介, 橘 大毅, 太田 裕貴
  • Organizer: 第11回マイクロ・ナノ工学シンポジウム
• [Presentation] 全方位計測可能な液体材料傾斜センサの作成 (2020)
  • Author(s): 松田 涼佑, 宋 子豪, 沖崎 章夫, 太田 裕貴
  • Organizer: 第11回マイクロ・ナノ工学シンポジウム
• [Presentation] Wearable Devices for Vital Sensing with Advanced Organic and Liquid Materials.” (2019)
  • Author(s): H. Ota
  • Organizer: 2019 IEEE International Symposium on Micro-NanoMechatronics and Human Science
  • Int'l Joint Research / Invited