Ionic polymer-metal composites - Fundamentals and phenomenological modeling

In this paper we present an extended summary of the fundamental properties and characteristics of Ionic Polymeric-Metal Composites (IPMC's) as biomimetic sensors, actuators and artificial muscles. Also, the phenomenological modeling of the underlying sensing and actuation mechanisms in IPMC's is presented based on linear irreversible thermodynamics with two driving forces; an electric field and a solvent pressure gradient and two fluxes, electric current and solvent flux. The importance of capacitors which arise from the nanoparticles residing at the surface/subsurface of IPMCs is also discussed. We also present some quantitative experimental results on the Onsager coefficients.