Matsuhisa, Naoji



Faculty of Science and Technology, Department of Electronics and Electrical Engineering (Yagami)


Assistant Professor/Senior Assistant Professor

E-mail Address

E-mail address

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Profile 【 Display / hide

  • Please find the latest publications in Google scholar.

Career 【 Display / hide

  • 2017.04

    The University of Tokyo, Electrical Engineering and Information Systems, Research scholar

  • 2017.05

    Nanyang Technological University, Materials Science and Engineering, Research scholar

  • 2017.08

    Stanford University, Chemical Engineering, Visiting scholar

  • 2019.04

    Stanford University, Chemical Engineering, Postdoctoral scholar

  • 2019.04

    Japan Society for the Promotion of Science, Overseas Research Fellow

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Academic Background 【 Display / hide

  • 2008.04

    The University of Tokyo, School of Engineering, Electrical and Electronic Engineering

    Japan, University, Graduated

  • 2012.04

    The University of Tokyo, Graduate School of Engineering, Electrical Engineering and Information Systems

    Japan, Graduate School, Completed, Master's course

  • 2014.04

    The University of Tokyo, Graduate School of Engineering, Electrical Engineering and Information Systems

    Japan, Graduate School, Completed, Doctoral course

Academic Degrees 【 Display / hide

  • Ph.D. in Engineering, Department of Electrical Engineering and Information Systems, Graduate School of Engineering, The University of Tokyo, Coursework, 2017.03


Research Areas 【 Display / hide

  • Electron device/Electronic equipment (Stretchable electronics)

  • Electronic materials/Electric materials (Soft materials)


Papers 【 Display / hide

  • High-frequency and intrinsically stretchable polymer diodes

    N Matsuhisa, S Niu, SJK O’Neill, J Kang, Y Ochiai, T Katsumata, HC Wu, ...

    Nature 600 (7888), 246-252 (Nature)  600 ( 7888 ) 246 - 252 2021

    Research paper (scientific journal),  ISSN  0028-0836

     View Summary

    Skin-like intrinsically stretchable soft electronic devices are essential to realize next-generation remote and preventative medicine for advanced personal healthcare1–4. The recent development of intrinsically stretchable conductors and semiconductors has enabled highly mechanically robust and skin-conformable electronic circuits or optoelectronic devices2,5–10. However, their operating frequencies have been limited to less than 100 hertz, which is much lower than that required for many applications. Here we report intrinsically stretchable diodes—based on stretchable organic and nanomaterials—capable of operating at a frequency as high as 13.56 megahertz. This operating frequency is high enough for the wireless operation of soft sensors and electrochromic display pixels using radiofrequency identification in which the base-carrier frequency is 6.78 megahertz or 13.56 megahertz. This was achieved through a combination of rational material design and device engineering. Specifically, we developed a stretchable anode, cathode, semiconductor and current collector that can satisfy the strict requirements for high-frequency operation. Finally, we show the operational feasibility of our diode by integrating it with a stretchable sensor, electrochromic display pixel and antenna to realize a stretchable wireless tag. This work is an important step towards enabling enhanced functionalities and capabilities for skin-like wearable electronics.

  • Strain-insensitive intrinsically stretchable transistors and circuits

    W Wang, S Wang, R Rastak, Y Ochiai, S Niu, Y Jiang, PK Arunachala, ...

    Nature Electronics 4 (2), 143-150 (Nature Electronics)  4 ( 2 ) 143 - 150 2021

    Research paper (scientific journal),  ISSN  2520-1131

     View Summary

    Intrinsically stretchable electronics can form intimate interfaces with the human body, creating devices that could be used to monitor physiological signals without constraining movement. However, mechanical strain invariably leads to the degradation of the electronic properties of the devices. Here we show that strain-insensitive intrinsically stretchable transistor arrays can be created using an all-elastomer strain engineering approach, in which the patterned elastomer layers with tunable stiffnesses are incorporated into the transistor structure. By varying the cross-linking density of the elastomers, areas of increased local stiffness are introduced, reducing strain on the active regions of the devices. This approach can be readily incorporated into existing fabrication processes, and we use it to create arrays with a device density of 340 transistors cm–2 and a strain insensitivity of less than 5% performance variation when stretched to 100% strain. We also show that it can be used to fabricate strain-insensitive circuit elements, including NOR gates, ring oscillators and high-gain amplifiers for the stable monitoring of electrophysiological signals.

  • Skin-like sensor systems by intrinsically stretchable electronic materials

    N Matsuhisa

    2021 28th International Workshop on Active-Matrix Flatpanel Displays and …    49 - 50 2021

    Research paper (scientific journal)

  • Metal–Ligand Based Mechanophores Enhance Both Mechanical Robustness and Electronic Performance of Polymer Semiconductors

    HC Wu, F Lissel, GJN Wang, DM Koshy, S Nikzad, H Yan, J Xu, S Luo, ...

    Advanced Functional Materials 31 (11), 2009201 (Advanced Functional Materials)  31 ( 11 )  2021

    Research paper (scientific journal),  ISSN  1616301X

     View Summary

    The backbone of diketopyrrolopyrrole-thiophene-vinylene-thiophene-based polymer semiconductors (PSCs) is modified with pyridine (Py) or bipyridine ligands to complex Fe(II) metal centers, allowing the metal–ligand complexes to act as mechanophores and dynamically crosslink the polymer chains. Mono- and bi-dentate ligands are observed to exhibit different degrees of bond strengths, which subsequently affect the mechanical properties of these Wolf-type-II metallopolymers. The counter ion also plays a crucial role, as it is observed that Py-Fe mechanophores with non-coordinating BPh4– counter ions (Py-FeB) exhibit better thin film ductility with lower elastic modulus, as compared to the coordinating chloro ligands (Py-FeC). Interestingly, besides mechanical robustness, the electrical charge carrier mobility can also be enhanced concurrently when incorporating Py-FeB mechanophores in PSCs. This is a unique observation among stretchable PSCs, especially that most reports to date describe a decreased mobility when the stretchability is improved. Next, it is determined that improvements to both mobility and stretchability are correlated to the solid-state molecular ordering and dynamics of coordination bonds under strain, as elucidated via techniques of grazing-incidence X-ray diffraction and X-ray absorption spectroscopy techniques, respectively. This study provides a viable approach to enhance both the mechanical and the electronic performance of polymer-based soft devices.

  • disp2ppg: Pulse Wave Generation to PPG Sensor using Display

    A Fujii, K Murao, N Matsuhisa

    2021 International Symposium on Wearable Computers, 119-123 (Proceedings - International Symposium on Wearable Computers, ISWC)     119 - 123 2021

    Research paper (scientific journal),  ISSN  9781450384629

     View Summary

    Wearable devices are often used to record the user's biometric information. Among biometric data, pulse data has been used in methods such as heart rate monitoring and emotion estimation. The most common type of pulse sensor is the photoplethysmogram (PPG), which irradiates a green LED on the skin and measures pulse data from changes in the light reflected through the blood vessels. PPG sensors have been implemented in commercially available wearable devices such as smartwatches. When a smartwatch is worn on an artificial body such as a prosthetic hand or a robotic arm, correct data cannot be acquired because there is no blood flow. In this study, we propose a method that enables the PPG sensor to measure arbitrary pulse data using a display. If this method is successful, it will be possible to input pulse data measured at the junction of the live body and the prosthetic hand to the display, and have the smartwatch attached to the prosthetic hand read the same pulse data. In this paper, we focus on the heart rate and report the results of an experiment in which a target heart rate was input and the display was controlled to determine whether the target heart rate could be obtained by a smartwatch. We implemented a display drawing program and conducted the evaluation using five kinds of smartwatches and four kinds of displays. Results showed that the error between the target heart rate and the heart rate acquired by the smartwatch was within ± 3 beats per minute in many cases.

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Awards 【 Display / hide

  • 井上研究奨励賞

    2019.02, 井上科学振興財団

    Type of Award: International Academic Awards

  • Student Poster Award

    2016.09, 2016 International Conference on Flexible and Printed Electronics (ICFPE)

    Type of Award: Awards of International Conference, Council and Symposium

  • Innovative Technologies 2015審査員特別賞”Human”(ダブル受賞)

    2015.10, 経済産業省

    Type of Award: Other Awards

  • Innovative Technologies 2015審査員特別賞”Industry”(ダブル受賞)

    2015.10, 経済産業省

    Type of Award: Other Awards


Courses Taught 【 Display / hide











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