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Jan et al. Soft Sci 2024;4:10 Soft Science
DOI: 10.20517/ss.2023.54

Research Article Open Access

A skin-wearable and self-powered laminated

pressure sensor based on triboelectric
nanogenerator for monitoring human motion

Agha Aamir Jan # , Seungbeom Kim # , Seok Kim *

Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of
Korea.
#
Authors contributed equally.
* Correspondence to: Prof. Seok Kim, Department of Mechanical Engineering, Pohang University of Science and Technology
(POSTECH), 77 Cheongam-Ro, Pohang 37673, Republic of Korea. E-mail: seok.kim@postech.ac.kr

How to cite this article: Jan AA, Kim S, Kim S. A skin-wearable and self-powered laminated pressure sensor based on
triboelectric nanogenerator for monitoring human motion. Soft Sci 2024;4:10. https://dx.doi.org/10.20517/ss.2023.54

Received: 24 Nov 2023 First Decision: 8 Dec 2023 Revised: 11 Dec 2023 Accepted: 22 Dec 2023 Published: 26 Jan 2024

Academic Editor: Zhifeng Ren Copy Editor: Pei-Yun Wang Production Editor: Pei-Yun Wang

Abstract
Flexible and skin-wearable triboelectric nanogenerators (TENGs) have emerged as promising candidates for self-
powered tactile and pressure sensors and mechanical energy harvesters due to their compatible design and ability
to operate at low frequencies. Most research has focused on improving tribo-negative materials for flexible TENGs,
given the limited options for tribo-positive materials. Achieving biocompatibility while maintaining the sensitivity
and capability of energy harvesting is another critical issue for wearable sensors. Here, we report a TENG-based
biocompatible and self-powered pressure sensor by simple fabrication of layer-by-layer deposition methods. The
Laminated Flexible-TENG comprises polytetrafluoroethylene (PTFE) and polymethyl methacrylate (PMMA) films
embedded within a flexible and biocompatible polydimethylsiloxane (PDMS) matrix. A nanostructured PDMS
surface obtained by oxygen plasma facilitated the sputter deposition of a layered indium tin oxide copper electrode
and a tribo-positive PMMA thin layer on top. The addition of the indium tin oxide layer to copper significantly
improved the quality and performance of the indium tin oxide-copper electrode. Self-powered Laminated Flexible-
TENGs demonstrated impressive pressure-sensing capabilities, featuring dual sensitivity of 7.287 V/kPa for low
pressure and 0.663 V/kPa for higher pressure. Moreover, the PDMS-encapsulated TENG sensor effectively traced
the physiological motions, such as wrist and finger bending, and efficiently harnessed the waste energy from
everyday physical activities, such as walking and jogging. The maximum peak-to-peak voltages of 18.3 and 57.4 V
were recorded during these motions. Encapsulated TENGs have broad potential in wearable technology, including
healthcare, human-machine interfaces, and energizing microelectronics.

Keywords: Self-powered, biocompatible, wearable sensor, triboelectric nanogenerator (TENG), energy harvesting,
human motion monitoring

© The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0
International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, sharing,
adaptation, distribution and reproduction in any medium or format, for any purpose, even commercially, as
long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and
indicate if changes were made.

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