Wearable fiberform hygroelectric generator

It is of great significance to develop the power generator that can proactively produce energy and apply it into next-generation wearable and self-powered electronics. Here, we fabricate a novel graphene oxide (GO)-based coaxial fiber-shaped hygroelectric generator (FHEG). The electricity generation under humidity variation results from the directional movement of charged hydrogen ions from GO. Under 70% humidity change, the FHEG can provide a high power density of ~ 0.21 µW cm⁻¹. The energy output can be easily enhanced by simple connection in series/parallel manner. Moreover, FHEG exhibits the outstanding shaping engineering characteristic, which can be transferred into diverse shapes and architectures on demand. Its excellent compatibility with woven fabrics enables the form-factor of electronic devices to be wearable and portable. Impressively, the integrated FHEG device can power many practical devices, indicating its widespread application in self-powered electronics and systems.