Gelatin-Based Conductive Hydrogel Wearable Sensor with Breathability and Adhesion

Conductive hydrogels have gained increasing attention due to their applications in flexible electronic devices and biosensors. Here, a gelatin-poly(vinyl alcohol) and LiCl composite conductive hydrogel (GP-Glu@LiCl) with good permeability and controllable adhesiveness was prepared by using gelatin and poly(vinyl alcohol) (PVA) as the gel matrix, 1-ethyl-(3-(dimethylamino)propyl) carbamoyldiimide (EDC) and N-hydroxybutanediimide (NHS) as cross-linking agents, and microbial fermentation as a pore making method. It is notable that the GP-Glu@LiCl hydrogel has adjustable pore size (139.99–315.52 μm), high permeability, high extensibility (with a tensile strain reaching 347.48%), good conductivity (1.78 S/m), and excellent adhesion strength. Moreover, the flexible sensor made of GP-Glu@LiCl hydrogel has high sensitivity and excellent strain sensing performance, which can be applied to the detection of human electrophysiological signals and the monitoring of changes in human movements. Through electromyogram (EMG) sensing, it enables the c ontrol of robotic arms and simple games. It has broad application prospects in wearable sensors and flexible electronic devices.