Lignin-Based Surface Adhesion Engineering Enables Tough Hydrogel for Flexible Epidermal Array Sensing

, demonstrating 9.4- and 18.6-fold enhancements over unmodified hydrogels. Accordingly, a hydrogel-elastomer hybrid bioelectrode is developed for physiological signal monitoring, showing a higher electromyography (EMG) signal-to-noise ratio (SNR) than commercial electrodes. Furthermore, a 6 × 4 electrode array is constructed and can maintain stable electrode-tissue interaction and 100% signal retention during intense contraction of biceps. This strategy provides new insight into the design of biomimetic adhesive hydrogels and promotes their application in wearable electronics.