Sensing–Actuation Integrated Hydrogels: Redefining Intelligent Soft Robotics

ABSTRACT Organisms achieve adaptive survival through highly integrated closed‐loop systems of perception, feedback, and execution. This highly coordinated structure–function collaboration mode provides important inspiration for the design of soft robots. However, current intelligent soft robots are typically based on modular integration of discrete sensing and actuation units, making it difficult to achieve organism‐like highly coordinated full‐surface sensing–actuation coupling. As functionally tunable intelligent materials with high water content, softness, biocompatibility, and stimulus‐responsive behavior, hydrogels can integrate sensing and actuation into one material structure, which lays a material foundation for the development of next‐generation intelligent soft robotic systems. In this review, we comprehensively discuss the design requirements for hydrogels used in soft robots across different application fields in terms of material properties, sensing capabilities, and actuation functions. Based on the diverse functionalities of hydrogels, we emphasize the importance of integrating sensing and actuation, with particular attention to the evolutionary trajectory from the integration of discrete functional modules to structure–function integration and ultimately to closed‐loop feedback intelligent systems. Finally, we provide insightful perspectives on the current challenges and prospects in the field. This review aims to provide a systematic reference for the design and development of highly integrated, adaptive, and autonomous soft robotic systems.