Annelid Skin Inspired Microstructure Strain Sensor Based on Conductive Polymer Hydrogel for Human Motion Monitoring and Gesture Recognition

Flexible conductive hydrogel strain sensors have attracted much attention in the fields of wearable electronics and medical treatment because of their excellent deformability and fabricability. However, these sensors still have limitations in achieving both high sensitivity and stability. Herein, inspired by the skin of annelids, we present a highly sensitive hydrogel based on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/poly(vinyl alcohol)/glycerol (PEDOT:PSS/PVA/GL) with a ridge-shape structure on the surface constructed by direct ink writing (DIW) printing technology. Our sensor exhibits high stretching sensitivity with a gauge factor of 5.1 (R2 = 0.99), excellent stretchability (300%), and good stability (>200 cycles). Based on the excellent performance, the strain sensor was successfully used to monitor various human motions, including bending of different joints and gesture recognition. Therefore, the conductive hydrogel-based strain sensor with bioinspired microstructure has promising applications in soft robots, electronic skin, and personal healthcare.