An Ionic polymer metal composites (IPMC) actuated 3D swimming microrobot is presented first. Inspired by biologic fins, passive plastic fin is attached to the IPMC strip to increase the thrust. Infrared sensors are equipped for wireless control and autonomous navigation. Then propulsive efficiency analyses are carried out. From the water electrolysis influence analysis of the IPMC, the best working voltage is confirmed. Finally, a two parts IPMC actuator is presented to improve the propulsive efficiency of the microrobot after the analysis of propulsive efficiency of caudal fin.