Performance enhancement of an ionic polymer metal composite actuator using a microcellular foaming process

Recently, the study of electroactive polymers that can be operated by electrical energy has attracted a great deal of attention. One type of electroactive polymer consisting of ionic polymer metal composites (IPMCs) is important because of its low driving voltage and fast response time, but the driving force gives limitations to the characteristics of IPMCs. In this research, we developed a high-performance IPMC using a new manufacturing process through a microcellular foaming process. Nafion (ionic polymer) films, foamed using a microcellular foaming batch process, and un-foamed Nafion films had a uniform thickness of platinum (Pt) deposited on them by electroless plating. To evaluate performance of the fabricated IPMCs, we tested changes in blocked force and free bending displacement of an IPMC actuator according to changes in applied voltage, water content and thickness of the sample. The foamed IPMC (fIPMC) actuator demonstrated 50% increased free bending displacement and twice larger blocked force than the normal (non-foamed) IPMC actuator. This result shows that the feasibility of attaining the same performance as a non-foamed IPMC with a lower applied voltage and of developing higher-performance IPMC actuators. Thus, we show the possibility of high-performance fIPMC actuators that may be useful in various fields.