Reusable Liquid Metal-Based Hierarchical Hydrogels with Multifunctional Sensing Capability for Electrophysiology Electrode Substitution

Electrophysiological electrode patches are often used to collect surface electrophysiological signals to monitor and evaluate human health. However, commercial Ag/AgCl gels are very susceptible to electrode-skin interface interference during rehabilitation exercises and cannot achieve a stable collection of electrophysiological signals. In order to solve this challenge, this paper designed a liquid metal-based hierarchical hydrogel, which has a series of great performances, including adhesion to various substrates, efficient self-healing ability, excellent stretchability, and conductivity. Due to the hydrogel's unique rheological and adhesive properties, a conformal electrode/skin interface was generated, thus enabling stable electrophysiological signal acquisition during exercise. In addition, the strain sensor assembled based on the conductive hydrogel can sensitively monitor human limb movements in real time and can even be used for remote intelligent gesture recognition. Therefore, this work provides scientific guidance for developing a next generation of intelligent hydrogels with personal health surveillance, rehabilitation training monitoring, and wearable human-machine interaction.