Long‐Lasting and High‐Power‐Density Yarn‐Based Moisture‐Enabled Electric Generator for Self‐powered Electronic Textiles

Abstract 1D moisture‐enabled electric generators (MEGs) hold great promise for powering electronic textiles, but their current limitations in power output and operational duration restrict their application in wearable technology. This study introduces a high‐performance yarn‐based moisture‐enabled electric generator (YMEG), which comprises a carbon‐fiber core, a cotton yarn active layer with a radial gradient of poly(4‐styrensulfonic acid) and poly(vinyl alcohol) (PSSA/PVA), and an aluminum wire as the outer electrode. The unique design maintains a persistent moisture gradient between the interior and exterior electrodes, enhancing performance through the continuous proton diffusion from PSSA and Al 3 ⁺ ions from the aluminum wire. The optimized 5‐cm‐long YMEG delivers an open‐circuit voltage of 1.35 V and a short‐circuit current density of 460 µA cm −2 , sustaining over 300 µA cm −2 for more than 5 h. When woven into a 1 m long yarn containing 95 YMEGs, it generates 101.0 V at 60% relative humidity. Additionally, a configuration of 420 YMEGs connected in series and parallel can power a 1 W LED and a 40 mW motor. This innovative YMEG design paves the way for self‐powered electronic textiles such as warning vests and headbands, capable of harnessing insensible sweat for energy.