Abstract
Hydrovoltaic nanogenerators, which harness small quantities of water to generate power, are gaining considerable attention for applications in next-generation wearable electronics. Conventional hydrovoltaic nanogenerators are constrained by their limited power density and suboptimal long-term stability. Therefore, a transpiration-driven electrokinetic power generator (TEPG) based on silk yarn coated with poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/divinyl sulfone (DVS) and designed as a wearable hydrovoltaic nanogenerator offering outstanding power generation efficiency and water stability is presented in this study. Given its hydrophilic surface, mechanical durability, and high aspect ratio, silk yarn is used to design a yarn-based TEPG system to achieve high spatial-efficiency and maximize volumetric power density. Furthermore, the covalent crosslinking agent, DVS, is introduced to sustain the long-term, high-power production efficiency of PEDOT:PSS. The devised yarn-type TEPG system generates a maximum power of 112 µW cm(-3) with artificial sweat. A system comprising 25 yarn-type TEPGs arranged in a series-parallel configuration is implemented utilizing the high spatial-efficiency of the sewable yarn-type TEPG. The results demonstrate the potential of wearable hydrovoltaic nanogenerators as next-generation renewable energy systems for wearable applications.