Bioinspired electrically conductive hydrogels: Rational engineering for next-generation flexible mechanosensors

Biological tissues, especially human skin, exhibit remarkable abilities to sense, adapt, and interface with surrounding environments, driving a significantly increasing interest in creating synthetic materials that can mimic these functions. Electrically conductive hydrogels (ECHs) represent a promising class of bioinspired materials poised to reshape the landscape of flexible mechanosensing technologies. Their intrinsic softness, biocompatibility, and tunable electrical conductivity enable them to serve as skin-like interfaces, translating mechanical stimuli (e.g., strain or pressure) into electronic signals. Despite the rapid development of ECHs, there still lacks a comprehensive understanding of the rational design principles, key functionalization strategies, and novel engineering methods, for achieving advanced mechanosensors. New applications in health monitoring, soft robotics, human-machine interactions, and plant monitoring also increasingly demand better sensitivity, durability, multifunctionality, and environmental stability of mechanosensors. This review consolidates the latest advances in ECH-based flexible mechanosensors, systematically analyzes the materials chemistry and mechanics that underpin their performance, and highlights the state-of-the-art fabrication approaches that expand their potential. By examining the principles and progress of this rapidly evolving field, we provide insights not only as a current benchmark for ECH-based sensor technologies but also as a strategic guide, illuminating pathways for future breakthroughs that can address pressing practical challenges.