Recent Progress in Bioinspired Design Strategies for Freeze Resistant Hydrogel Platforms toward Flexible Electronics

Hydrogel-based flexible electronics have attracted great attention due to their excellent mechanical properties, high conductivity, sensitivity to electric signals, etc. Yet it is extremely challenging to create a freeze-resistant hydrogel for desired signal stability due to inevitable water crystallization at low temperature. Inspired by the inherent freezing tolerance of many biological organisms, researchers have devoted extensive efforts to developing advanced hydrogel materials with freeze-tolerant attributes and have made considerable progress. Herein, we present a comprehensive analysis of the cutting-edge developments in freeze-resistant hydrogels, underpinned by insights from nature and the frontiers of material engineering. We commence by delineating the intrinsic freeze-tolerance mechanisms inherent in organisms adapted to frigid environments. Following this, we collate the engineering methodologies tailored to develop antifreeze hydrogels. Subsequent sections illuminate the pioneering strides in applying these materials to diverse technological arenas, including flexible sensors, smart actuators and robotics, energy storage devices, and energy harvesters. Finally, the perspectives on future challenges and the avenues steering the accelerated evolution of such bioinspired materials are discussed. This review sheds light on the strides made in material innovation and structural design of freeze resistant hydrogels, anticipating the facilitation of the operation adaptation of soft electronic devices in extreme environments.