Ultrathin, Antibacterial, and Environmentally Resilient Fiber-Reinforced Organohydrogels for High-Fidelity Epidermal Bioelectronics

Abstract

The development of ultrathin, mechanically robust, and multifunctional ion-conducting hydrogels is paramount for next-generation wearable bioelectronics, yet achieving a synergy between high toughness, environmental resilience, and long-term antibacterial activity remains a formidable challenge. Herein, an ultrathin polyacrylamide/phytic acid-thermoplastic polyurethane/poly(ethylene oxide) (PAM/PA-TO) fiber-based organohydrogel composite membrane is fabricated by infiltrating an electrospun nanofiber framework into an ionic polymer network. The integrated TO fiber skeleton, combined with synergistic hydrogen bonding and chain entanglements, endows the composite membrane with exceptional mechanical properties, including a high tensile strength of 2479 kPa, a large fracture strain of 674%, and a phenomenal toughness of 12866.7 kJ/m3. Notably, the incorporation of PA provides intrinsic antibacterial activity (inhibitory zones of 22–27 mm) and sustained antimicrobial efficacy for over 14 days, effectively preventing bacterial colonization and biofilm-induced performance degradation. Benefiting from a glycerol/water binary solvent system, the organohydrogel exhibits excellent antifreezing flexibility at −20 °C and outstanding water retention (70.6% mass retention after 5 days). As a flexible strain sensor, the membrane demonstrates high sensitivity (Gauge factormax = 5.88), rapid response (160 ms), and remarkable durability over 7000 cycles. Furthermore, its ultrathin profile and conformal tissue adhesion enable high-fidelity monitoring of subtle electromyography (EMG) and electrocardiogram (ECG) signals with superior signal-to-noise ratios compared to commercial electrodes. This work provides a viable strategy for designing resilient and antibacterial epidermal electronics targeting personalized healthcare and motion perception.