An Ionic Hydrogel-Based Antifreezing Triboelectric\nNanogenerator

Abstract

The rapid development of stretchable\nelectronics and soft robotics\nrequires a sustainable power source that can match their mechanical\nstretchability in various working environments. Ionic hydrogel-based\nsoft triboelectric nanogenerators (TENGs) show great promise for those\napplication scenarios. However, ionic hydrogel-based TENGs suffer\nfrom the freezing issue under subzero temperatures. In this study,\na low-cost, highly stretchable, and antifreezing ionic triboelectric\nnanogenerator (iTENG) is designed to involve a dielectric elastomer\nand a freeze-tolerant ionic hydrogel as the electrification layer\nand the electrode, respectively. The iTENG design achieves a unique\ncombination of merits such as robust hydrogel–elastomer bonding,\nhigh stretchability (300%), and excellent tolerance of extremely low\ntemperature (down to −53 °C). Because of the reliable\ninterfacial bonding, the iTENG shows a good mechanical durability\nunder different stretching conditions. The iTENG can harvest mechanical\nenergies from various human motions and can also serve as a self-powered\nwearable sensor in both regular and extremely cold environments. The\nstretchable iTENG overcomes the strain-induced performance degradation\nof existing stretchable materials with percolated conductive fillers\nand the water freezing-induced degradation of conductive ionic hydrogels,\nproviding a feasible design of stretchable and sustainable power sources\nfor stretchable electronics and soft robotics operating in harsh environments.