Recent Advances in Stimuli-Responsive Conductive Hydrogels for Smart Sensing and Actuation: Properties, Design Strategies, and Applications

Conductive hydrogels are a class of multifunctional composites constructed by introducing conductive components into a three-dimensional polymer network, combining the high water-content, stretchability, and biocompatibility of traditional hydrogels. In recent years, researchers have developed stimuli-responsive conductive hydrogels (SRCHs) through molecular functionalization design, which can respond to external stimuli such as mechanical stress, temperature, pH, light, electric field, etc., and realize electrical signal output or mechanical behavior modulation, so as to satisfy the requirements of smart devices for dynamic sensing and active response of materials. Thanks to the synergistic effect of active environmental responsiveness and electrical conductivity, SRCHs show a broad application prospect in smart sensing and actuation. However, due to the complexity of the environment, it is still difficult to utilize SRCHs materials to construct sophisticated smart devices. This paper systematically reviews the progress of SRCHs in material design and smart sensing and actuation applications in the past five years, focuses on their stimuli-responsive mechanisms and performance optimization strategies, and summarizes the current challenges and future development directions, with a view to providing theoretical references and technological inspirations for the development of next-generation smart materials.