Moisture-driven fabric-based generator for powering wearable electronics

Moist-electric generators (MEGs) can continuously harvest electricity through asymmetric ion movement under a moisture gradient. Herein, we developed a self-gradient structure, in which a functional polyelectrolyte (polyvinyl alcohol) matrix is vertically and non-uniformly distributed by gravity in a knitted fabric as a framework, which constructs a moisture gradient in an open environment. Interestingly, a conjugated fabric stacked on the moist-electric fabric with a self-gradient structure not only accelerates the evaporation of water, boosting the moisture gradient, but creates an asymmetric hygroscopic structure, generating a streaming potential effect. Based on the above structure, an all-fabric MEG (F-MEG) is created, which achieves energy conversion via a self-moisture gradient in an open environment while offering permeability and comfort for dress requirements. The material we have demonstrated in this study advances current research in sustainable energy generated from the body surface microclimate. This opens the potential for F-MEG garments to power continuously portable electronics.