Actuating and electrochemical behaviors of nafion-based electrode were strongly dependent on the interfacial area between the electrode and the polymer electrolyte. A replication method was utilized to manufacture a large surface-area composite actuator. Measurement of double layer charging and scanning electron microscopy indicated that the interfacial area could be greatly increased by replication method. Larger interfacial area induced a better bending performance of ionic polymer metal composite (IPMC) (the magnitude of IPMC increased about 50% at 3 V). The surface resistance of IMPC and the effects of cations on IPMC were investigated with constant current experiment. cyclic voltammetry and electrochemical impedance spectroscopy (EIS).