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Zhao et al. Soft Sci. 2025, 5, 10 Soft Science
DOI: 10.20517/ss.2024.61

Research Article Open Access

Printed graphene/CNTs/TPU-fabric wearable strain

sensor for healthcare monitoring

1
1,*
1
1
1
2
Weikai Zhao , Pei He , Kai Ling , Chen Gao , Kaifeng Wang , Lin Wu , Junliang Yang 2,3,*
1
School of Electronic Information, Central South University, Changsha 410083, Hunan, China.
2
Hunan Key Laboratory for Super-microstructure and Ultrafast Process, School of Physics, Central South University, Changsha
410083, Hunan, China.
3
FuRong Laboratory, Changsha 410078, Hunan, China.
* Correspondence to: Dr. Pei He, School of Electronic Information, Central South University, 932 Lushan South Road, Changsha
410083, Hunan, China. E-mail: pei.he@csu.edu.cn; Prof. Junliang Yang, Hunan Key Laboratory for Super-microstructure and
Ultrafast Process, School of Physics, Central South University, 932 Lushan South Road, Changsha 410083, Hunan, China. E-mail:
junliang.yang@csu.edu.cn
How to cite this article: Zhao, W.; He, P.; Ling, K.; Gao, C.; Wang, K.; Wu, L.; Yang, J. Printed graphene/CNTs/TPU-fabric
wearable strain sensor for healthcare monitoring. Soft Sci. 2025, 5, 10. https://dx.doi.org/10.20517/ss.2024.61
Received: 31 Oct 2024 First Decision: 25 Nov 2024 Revised: 1 Jan 2025 Accepted: 2 Jan 2025 Published: 6 Feb 2025
Academic Editors: Seung Hwan Ko, Carlo Massaroni Copy Editor: Ting-Ting Hu Production Editor: Ting-Ting Hu

Abstract
Wearable strain sensors hold immense promise in monitoring human motion activities due to their low cost,
lightweight design, and excellent biocompatibility. For example, continuous real-time monitoring of neck activity
can effectively prevent the onset of acute torticollis. However, current approaches to monitoring sleep neck
posture primarily depend on technologies such as computer vision, which are characterized by limited wearability
and portability issues. Herein, this work introduces a cost-effective, highly sensitive carbon-based strain sensor
fabricated on a fabric substrate with a printing technique, which is eco-friendly and biocompatible. The proposed
sensor displays a broad sensing range of 112%, high sensitivity (gauge factor > 210), low sensing limit (~ 0.1 ‰), and
outstanding long-term stability over 3,000 cycles. The sensor’s utilization in monitoring joint motion, vocal cord
activity, pulse, and electrocardiogram (ECG) is illustrated. Moreover, a portable system for monitoring neck activity
and ECG signals while sleeping has been engineered, capable of detecting neck movements and ECG signals during
sleeping hours. The composite materials design strategy combined with printing techniques provides a potential
route for high-performance and low-cost wearable strain sensors in health monitoring.

Keywords: Strain sensors, sleep posture monitoring, multimodal monitoring, wearable system

© The Author(s) 2025. 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
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