Characterization of the electromechanical properties of ionomeric polymer-metal composite (IPMC)

IPMC is an electroactive polymer (EAP) that has been the subject of research and development since 1992. The advantages of IPMC in requiring low activation voltage and the induced large bending strain led to its consideration for various potential applications. However, before the benefits of IPMC can be effectively exploited for practical use, the electromechanical behavior of this group of EAP materials must be properly understood and quantified. An experimental setup was developed for data acquisition from IPMC strips that are subjected to various tip mass load levels. This data acquisition setup was used to measure the displacement and curvature of IPMC as a function of the input signal. Sample strips were immersed in water to minimize the effect of moisture content. In order to avoid electrolysis, the samples were subjected to 1-V square wave with either positive or negative polarity. Experiments have shown that IPMC has history dependence and the characteristics response is dominated by the backbone (e.g., Nafion, Flemion, etc.) and ionic content (e.g., Na+, Li+, etc.).