Researchers solve humidity problem that ruins energy-harvesting devices
Scientists have engineered a hydrogel coating that fixes a critical flaw in triboelectric nanogenerators—devices that convert motion into electricity. The material maintains power output even in wet conditions and resists bacterial buildup, making it viable for marine and medical applications where current technology fails.
Originaltitel: 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.