Preparation of Active On-Demand Antibacterial Hydrogel Epidermis Electrodes Based on Flora Balance Strategy for Intelligent Prostheses

Hydrogel epidermis electrodes have demonstrated remarkable potential for stable electrophysiological signal acquisition in the field of intelligent prostheses. However, current hydrogel electrodes face challenges in providing on-demand antibacterial effects due to dynamic skin conditions, such as sweating, which may induce skin inflammation, thus limiting their practical applications. Herein, an active on-demand antibacterial hydrogel electrode is prepared by encapsulating Staphylococcus epidermidis (S. epidermidis) into the hydrogel electrode based on the strategy of flora balance. The encapsulated S. epidermidis metabolizes nutrients from sweat to produce antibacterial substances, achieving an 82% inhibition rate against Staphylococcus aureus over a 24-h period. With on-demand antibacterial properties, low interfacial impedance, and strong adhesion, the hydrogel electrode enables the acquisition of various high-quality electrophysiological signals with a signal-to-noise ratio of 22.2 dB after 12 h of attachment, much higher than that of commercial hydrogel electrodes. When combined with machine learning models to decode electromyographic signals, the electrode system achieves the high gesture recognition accuracy of 95%. Furthermore, the stable signal acquisition enabled by the antibacterial hydrogel electrode facilitates real-time wireless control of robotic hands, providing a robust technical platform for intelligent prosthetic applications.