A Stretchable and Tough Small-Scale Magnetic Actuator for Biomedical Applications

A stretchable, tough, small-scale magnetic actuator capable of multimodal locomotion under magnetic fields is proposed. The actuator consists of a silicone elastomer (Ecoflex 00-10) embedded with neodymium-iron-boron (NdFeB) particles and coated with a poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) triple network hydrogel layer. The hydrogel layer is biocompatible and decreases the surface friction of the actuator. Mechanically, the actuator is highly stretchable, tough, and fatigue-resistant. The application of the actuator in drug delivery is demonstrated.