The behavior of ionic polymer–metal composites in a multi-layer configuration

It has been observed that an ionic polymer-metal composite (IPMC) is both inherently resistive and capacitive. This allows for the material to be modeled using an equivalent RC circuit to describe the charging/discharging behavior associated with the IPMC. Typically, the model includes two resistors and two capacitors, which will primarily account for the effective electrodes on the surface of the IPMC (top and bottom). There will also be a resistor placed between the two RC circuits to account for material between the electrodes and the resistance due to ion migration through the polymer matrix. In this paper we report our recent effort to extend such a model to accommodate a multi-layer IPMC as well as inter-digitated electrodes. As expected, the observed electric characteristics of an IPMC subjected to an electric field are highly non-linear. This is believed to be due primarily to the particle electrodes on the IPMC surface, which is inherently both capacitive and resistive due to particle separation and density. The advantage of using such a model is to realize the capacitive and resistive effects and use them for a multi-layer configuration. We also present typical experimental data.