High-Performance Conductive and Antibacterial Zwitterionic Hydrogel for the Design of Flexible Motion Sensor

To address the challenge of optimizing biocompatibility, mechanical robustness, and antibacterial efficacy in flexible electronic skin materials, a high-performance conductive and antibacterial zwitterionic hydrogel (ASCC) was developed utilizing sulfobetaine methacrylate (SBMA) and carboxymethyl chitosan (CMCS). By copolymerizing SBMA with acrylamide (AAm) to form dynamic ionic channels and integrating CMCS-driven multiple physical cross-linking networks (including hydrogen bonds, electrostatic interactions, and hydrophobic effects), the hydrogel demonstrated remarkable mechanical properties─namely a maximum tensile strain of 1113.44% and toughness of 741.02 kJ·m –3 . It also exhibited high ionic conductivity (1.48 S/m) and sustained stability, maintaining performance after 3000 cycles. Exploiting the bioinert nature of SBMA alongside the antimicrobial properties of CMCS, the ASCC hydrogel showed exceptional biocompatibility (cell viability >90%) and broad-spectrum antibacterial efficacy (>93% inhibition against Escherichia coli and Bacillus subtilis ). Moreover, its significant transparency (>90% visible-light transmittance) and rapid response capability (50 ms response time) facilitated real-time monitoring of multiscale human movements, such as joint bending, vocalization, and facial microexpressions, while sustaining a stable linear resistance-strain relationship (GF = 5.11). This study introduces an innovative strategy for designing flexible electronic skins with integrated biosafety, mechanical durability, and multifunctional sensing capabilities.