Programmable magnetic hydrogel robots with drug delivery and physiological sensing capabilities

Magnetic hydrogels are promising materials for the construction of magnetic soft robots applied in robotic systems and implantable devices. However, programming geometric shapes and magnetization profiles of magnetic hydrogel robots (MHRs), as well as integrating functional modules into robotic systems, remain challenging. Here, we report an assembly strategy for MHRs with programmable magnetization profiles and geometries, constructed from discrete integration of magnetized hydrogels and a patterned elastomer membrane based on covalent crosslinking. The resulting robots exhibit sophisticated deformations under varying magnetic fields, enabling effective carrying and delivery of solid drugs. Moreover, the proposed fabrication method preserves the highly porous and hydrophilic microstructures of the hydrogels, facilitating loading, adhesion, and transport of liquid drugs in combination with magnetic properties. Besides, integrating ultrathin and multifunctional microfabricated electronics into the MHRs is also achieved for physiological sensing and simulation, which has negligible effects on their intrinsic mechanics and deformability. The introduction of these magnetic materials and fabrication methods can shed new insights for the development of advanced biomedical tools and robotic systems.