Hydrogel‐Based Motors

Abstract Inspirations from the movements of organisms in nature have motivated a myriad of researchers to develop innovative intelligent soft matter mimicking the body deformation principles of natural systems. Similar to the sensory and control systems of biological organisms, the environment responsiveness and configurable structure of hydrogel make it an ideal candidate to construct biomimetic soft matters. This review highlights the progresses made toward developing hydrogel‐based motors from two aspects: chemically induced autonomous propulsion and external‐stimuli‐induced propulsion. According to the classification based on propulsion mechanisms, the design principles, fabrication methods, and motion characterization are discussed. By reviewing the efforts in the rapidly increasing multidisciplinary field, the framework of designing hydrogel‐based smart soft devices able to operate autonomously is outlined and ongoing research targets to meet the intended purpose are proposed.