Antibacterial and Multiresponsive Electronic Skins from Silk Fibroin Triple-Network Hydrogels

Silk fibroin (SF) is an attractive matrix for flexible bioelectronics owing to its biocompatibility and chemical tunability, yet its limited mechanical robustness, lack of antibacterial function, and unstable electrical performance constrain its broader application. Here, we report a triple-network ionic hydrogel engineered from methacrylated SF (SFMA), acrylate-terminated silicone (SilMA), and the cationic monomer METAC. The SFMA/SilMA/METAC (SSM) hydrogel forms a uniform interpenetrating network that markedly strengthens mechanical properties, suppresses swelling and component leaching, and achieves >99% antibacterial efficacy against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), while preserving excellent cytocompatibility. As a resistive iontronic e-skin, the SSM hydrogel exhibits high pressure sensitivity (2.14 kPa^-1), rapid response/recovery (6/12 ms), a low detection limit of 20 Pa, and long-term stability over 1500 cycles at 20 kPa with <2.3% signal decay. In addition, the hydrogel enables reversible pH sensing across pH 4.00-9.18 with a sensitivity of 21 pH^-1, representing the first demonstration of dual-mode pressure and pH sensing in an SF-based ionic hydrogel. These combined features allow precise monitoring of human motion and underscore the potential of SSM hydrogels for intelligent wound care and implantable bioelectronic interfaces.