Turning moisture into a benefit: Chitosan-reinforced pSBMA/pAAc hydrogel for wear-resistant, humidity-enhanced and anti-biofouling TENG

Triboelectric nanogenerators (TENGs) suffer from charge leakage under humid environments. In particular, marine/biomedical interfaces indicate that biofouling may present a critical challenge such as protein adsorption and microbial adhesion that distort interfacial electrostatics, accelerate charge dissipation and trigger progressive failure of output performance. To address these coupled challenges, we developed a chitosan-reinforced poly(sulfobetaine methacrylate- co -acrylic acid) (pSBMA/pAAc) hydrogel that integrates anti-biofouling ability, wear resistance, and humidity-enhanced electrical output. The interpenetrating polymer network (IPN) couples a pSBMA/pAAc copolymer that forms a tightly bound hydration layer with a crosslinked chitosan network that reinforces mechanical strength, suppresses swelling, and provides strong interfacial adhesion. The resulting hydrogel exhibits ultralow protein adsorption (4.9 μg/cm 2 ), high adhesion strength (325 kPa), and superior wear resistance. Additionally, TENG device fabricated from the hydrogel (tribo-positive layer) and FEP (tribo-negative layer) delivers a humidity-enhanced output voltage increasing from 16 V to 30 V as relative humidity (RH) increases from 28% to 80%. The proposed hydrogel transforms moisture from a detrimental factor into an active performance enhancer. Finally, density functional theory (DFT) calculations reveal the microscopic origin of this humidity-enhanced behavior of the TENG device. Hence, this materials-level strategy integrates passive anti-biofouling with humidity-enhanced charge transfer, enabling robust TENG operation for energy harvesting and sensing in moist and biofouling-prone environments. • Chitosan-reinforced pSBMA/pAAc hydrogel coating with anti-biofouling and humidity-enhanced TENG output. • Shows ultralow protein adsorption (4.9 μg/cm 2 ) and strong adhesion (325 kPa). • Delivers voltage increase from 16 V to 30 V as RH rises (28–80%). • DFT confirms bound-water-mediated charge stabilization under humid conditions.