A highly flexible fabric-based hydrovoltaic generator with a core-sheath structure for wearable applications

Abstract

Flexible hydrovoltaic generators, which sustainably convert abundant water resources in nature into electrical energy, have attracted significant attention in the field of wearable electronics. However, owing to the low surface charge density and poor charge transfer capability of the current active materials in hydrovoltaic generators, challenges remain in realizing high power output, large-scale integration, and wearable practical applications. In this work, a novel approach is proposed using a self-assembly and in situ growth method to fabricate a hydrovoltaic device based on a core-sheath structure composed of negatively charged Ti₃C₂T_X MXene (MXene) as the matrix material and positively charged conductive polypyrrole (PPy). This design simultaneously achieves high conductivity and surface charge density and has been successfully applied to wearable hydroelectric energy conversion. The resulting device exhibits a peak current of 4.07 mA and a maximum power output of 215 μW, outperforming most existing hydrovoltaic generators. The cotton fabric-based hydrovoltaic generator with a continuous core-sheath structure developed in this study not only enhances electricity generation under water diffusion but also demonstrates sensitive sensing signals in response to solution fluctuations (1283.08 μA M⁻¹), creating new possibilities for flexible self-powered wearable hydrovoltaic electronic devices.