Highly Conductive Cellulose Strain Sensor with Excellent Negative Resistance Variation and Joule Heating Property
Guichun Hu, Hong Zhao, Na Zhong, Heng Zhao, Hongguang Zhang, Aimei Zang, Fangong Kong, Jinguang Hu
Abstract
The rational design of a wearable strain sensor with heating property has attracted great interest. In this study, a flexible conductivity hierarchical cellulose strain sensor (MX@Ag@CY) with heating property was fabricated via in situ formation of silver nanoparticles (Ags) on cotton yarn (CY) and subsequent dip-coating with MXene (MX). Ags coupled with MX coating endowed the cotton yarn with a high conductivity, where the resistance of the optimized composite MX@Ag 0.47 @CY was about 22 Ω/cm. Compared with the previously reported strain sensors, the woven MX@Ag 0.47 @CY fabric strain sensor showed a distinctive negative resistance variation, wherein it showed an enhanced conductivity with the increased strain owing to its unique architecture. The woven MX@Ag 0.47 @CY fabric strain sensor exhibited a repeatable response and displayed long-term stability in the strain range of 0–55%. In addition, the strain sensor demonstrated great detectability on large-scale human movements when directly attached to the elbow, wrist, or knee. Furthermore, when MX@Ag 0.47 @CY served as a heater (at an applied DC voltage of 6 V), it presented high heating temperature (92.4 °C), homogeneous temperature distribution, low operation voltage (1–6 V), and excellent thermal stability even under strain.