Degradable and stretchable bio-based strain sensor for human motion detection

Shifeng Zhang; Hongqiang Li; Zhipeng Yang; Baodeng Chen; Kunquan Li; Xuejun Lai; Xingrong Zeng

doi:10.1016/j.jcis.2022.06.171

Degradable and stretchable bio-based strain sensor for human motion detection

J Colloid Interface Sci. 2022 Nov 15:626:554-563. doi: 10.1016/j.jcis.2022.06.171. Epub 2022 Jun 30.

Authors

Shifeng Zhang¹, Hongqiang Li², Zhipeng Yang¹, Baodeng Chen¹, Kunquan Li³, Xuejun Lai¹, Xingrong Zeng⁴

Affiliations

¹ School of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Polymer Materials, South China University of Technology, Guangzhou 510640, China.
² School of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Polymer Materials, South China University of Technology, Guangzhou 510640, China. Electronic address: lihq@scut.edu.cn.
³ School of Materials Science and Engineering, Dongguan University of Technology, Dongguan 523808, China. Electronic address: kqli@dgut.edu.cn.
⁴ School of Materials Science and Engineering, Key Lab of Guangdong Province for High Property and Functional Polymer Materials, South China University of Technology, Guangzhou 510640, China. Electronic address: psxrzeng@gmail.com.

PMID: 35809444
DOI: 10.1016/j.jcis.2022.06.171

Abstract

In recent years, flexible strain sensors have attracted considerable attention for the great application potential in the emerging fields of wearable devices, electronic skin and health monitoring. However, most of flexible strain sensors are nondegradable, and the produced numerous electronic wastes after uselessness will seriously threaten environment and ecology. Herein, we propose a new strategy to fabricate degradable and stretchable bio-based strain sensor using candle soot (CS) particles to construct conductive pathways and chitosan, potato starch (PS), and polyvinyl alcohol (PVA) to form stretchable matrix in the presence of Fe³⁺ ions. Owing to the formation of multiple hydrogen bonding constructed by chitosan, PS and PVA as well as coordination bonding by Fe³⁺ ions, the obtained strain sensor showed high elongation at break up to 200% and good fatigue resistance. Furthermore, the firm embedding of the CS particles into the surface of the stretchable matrix endowed the strain sensor with steady sensitivity (gauge factors of 1.49 at 0-60% strain and 2.71 at 60-100% strain), fast response (0.22 s) and good repeatability even after 1000 stretching-releasing cycles. In addition, the strain sensor was successfully applied to detect various human motions including finger and wrist bending, swallowing and pronunciation. Interestingly, after connecting to an Arduino microcontroller circuit with a Bluetooth module, the strain sensor was able to wirelessly detect real-time movements of index finger joints. Different from most previously reported sensors, the prepared strain sensor in this work was completely degraded in 2 wt% CH₃COOH solution at 90 °C only within 10 min, thus effectively avoiding the production of electrical waste after the updating and upgrading of the sensors. The findings conceivably stand out as a new methodology to prepare environmental-friendly sensors in the field of flexible electronics, which is very beneficial for the sustainable development of environment and society.

Keywords: Chitosan; Degradable; Human motion detection; Potato starch; Strain sensor; Wireless sensing.

MeSH terms

Chitosan*
Humans
Ions
Motion
Movement
Wearable Electronic Devices*

Substances

Ions
Chitosan