Emergent Soft System Research Team

Principal Investigator

PI Name Takao Someya
Degree Ph. D.
Title Team Leader
Brief Resume
1997 Ph.D., Electronic Engineering, University of Tokyo
1997 Research Associate, University of Tokyo
1998 Lecturer, University of Tokyo
2001 JSPS Postdoctoral Fellowship for Research Abroad (Columbia University)
2002 Associate Professor, University of Tokyo
2009 Professor, University of Tokyo (-present)
2015 Chief Scientist, Thin-film deice lab, RIKEN (-present)
2015 Team Leader, Emergent Soft System Research Team, Supramolecular Chemistry Division, RIKEN Center for Emergent Matter Science (-present)
2020 Dean, School of Engineering, University of Tokyo
2023 Executive Director and Vice President, University of Tokyo (-present)


Electronics is expected to support the foundation of highly develop ICT such as Internet of Things (IoT), artificial intelligence (AI), and robotics. In addition to improve the computing speed and storage capacity, it is required to minimize negative impact of machines on environment and simultaneously to realize the harmony between human and machines. We make full use of the novel soft electronic materials such as novel organic semiconductors in order to fabricate emergent thin-film devices and, subsequently, to realize emergent soft systems that exhibit super-high efficiency and harmonization with humans. The new soft systems have excellent features such as lightweight and large area, which are complimentary to inorganic semiconductors, are expected to open up new eco-friendly applications.

Research Fields

Electronic Engineering, Materials Science


Organic electronics
Organic field-effect transistor
Organic light emitting devices
Organic solar cells
Organic sensors


Ultraflexible, high-performance and stable organic solar cells

One of the requirements of the Internet of Things—referring to a world where devices of all sorts are connected to the Internet—is the development of power sources for a host of devices, including devices that can be worn on the body. These could include sensors that record heartbeats and body temperature, for example, providing early warning of medical problems. In the past, attempts have been made to create photovoltaics that could be incorporated into textiles, but typically they lacked at least one of the important properties—long-term stability in both air and water, energy efficiency, and robustness including resistance to deformation—that are key to successful devices.

We have developed an ultraflexible organic photovoltaic (OPV) that achieves sufficient thermal stability of up to 120 °C and a high power conversion efficiency of 10% with a total thickness of 3 μm. Additionally, our ultraflexible organic solar cells exhibit prolonged device storage lifetime to >2,000 h at room temperature. Our ultraflexible OPVs possessing extraordinary thermal durability allow a facile bonding onto textiles through the hot-melt adhesive technology.

Photographs of organic solar cells

(Left) Ultraflexible organic solar cells manufactured on a 1 μm-thick plastic film.
(Right) Photograph of the washing process for the devices conforming to a dress shirt.


Takao Someya

Team Leader takao.someya[at]riken.jp

Kenjiro Fukuda

Senior Research Scientist

Sunghoon Lee

Research Scientist

Sixing Xiong

Postdoctoral Researcher

Ruiqi Guo

Postdoctoral Researcher

Younguk Cho

Visiting Scientist

Shuxu Wang

Visiting Researcher

Shin Young Lee

Senior Technical Staff

Baocai Du

Student Trainee

Wenqing Wang

Student Trainee

Shumpei Katayama

Junior Research Associate

Karin Iwa

Administrative Part-time Worker II


  1. S. Xiong, K. Fukuda, K. Nakano, S. Lee, Y. Sumi, M. Takakuwa, D. Inoue, D. Hashizume, B. Du, T. Yokota, Y. Zhou, K. Tajima, and T. Someya

    Waterproof and ultraflexible organic photovoltaics with improved interface adhesion

    Nat. Commun. 15, 681 (2024)
  2. Z. Jiang, N. Chen, Z. Yi, J. Zhong, F. Zhang, S. Ji, R. Liao, Y. Wang, H. Li, Z. Liu, Y. Wang, T. Yokota, X. Liu, K. Fukuda, X. Chen, and T. Someya

    A 1.3-micrometre-thick elastic conductor for seamless on-skin and implantable sensors

    Nat. Electron. 5, 784-793 (2022)
  3. Y. Kakei, S. Katayama, S. Lee, M. Takakuwa, K. Furusawa, S. Umezu, H. Sato, K. Fukuda, and T. Someya

    Integration of body-mounted ultrasoft organic solar cell on cyborg insects with intact mobility

    npj Flex. Electron. 6, 78 (2022)
  4. M. Takakuwa, K. Fukuda, T. Yokota, D. Inoue, D. Hashizume, S. Umezu, and T. Someya

    Direct gold bonding for flexible integrated electronics

    Sci. Adv. 7, eabl6228 (2021)
  5. S. Park, S. W. Heo, W. Lee, D. Inoue, Z. Jiang, K. Yu, H. Jinno, D. Hashizume, M. Sekino, T. Yokota, K. Fukuda, K. Tajima, and T. Someya

    Self-powered ultra-flexible electronics via nano-grating-patterned organic photovoltaics

    Nature 561, 516 (2018)



Cooperation Center W405
2-1 Hirosawa, Wako, Saitama 351-0198 Japan