Wireless microactuators provide a broad range of application opportunities. One promising area is biomedical applications, including therapeutic implants and microsurgical tools. In these medical areas, shape-memory-alloy (SMA) actuators offer attractive features such as very large actuation forces, high mechanical robustness with simple structures, and biocompatibility. Stimuli-responsive hydrogels are also promising smart materials that can be used as soft microactuators suitable for many biomedical applications. The ability to control multiple microactuators selectively in a wireless manner will be a key to achieving novel functionalities while enhancing their performance. For implantable drug-delivery devices, for example, this ability may be utilized to enable the controlled and selective delivery of different types of drugs at specific mixtures for use in various clinical applications including pain control methods  as well as diabetic  and glaucoma treatments .