Combining Soft and Hard Properties: Synergistic Innovation of Magnetic Hydrogel Microrobots in Precision Medicine

Currently, untethered soft robots represent a rapidly advancing research direction. Among various advanced flexible materials, magnetic hydrogels have attracted significant attention due to their unique properties, and research on microrobots based on this material has become increasingly in-depth. Compared with traditional wired soft robots, magnetic microrobots (MMBs) possess the advantages of non-invasive operation and remote, precise control, enabling spatiotemporal integrated control. This review systematically elaborates on the latest progress in magnetic hydrogel microrobots (MHMs), focusing on the dual design of materials and functions, innovations in bionic structures, breakthroughs in driving mechanisms, and exploration of cutting-edge applications. The article specifically analyzes the material optimization strategies and functional integration designs for microrobots, provides a detailed explanation of their multimodal driving mechanisms (such as magneto-optical/magneto-acoustic synergistic drive, etc.), and thoroughly elaborates the implementation of bionic inspiration in structural design. Such robots demonstrate remarkable potential in biomedical fields, including targeted cancer therapy, precise drug delivery, and diagnosis and treatment of gastrointestinal diseases, as well as in environmental management. Finally, the opportunities (e.g., swarm control) and challenges (e.g., poor deformation) are innovatively summarized, providing forward-looking insights for the technological breakthroughs and widespread applications of magnetic soft microrobots.