Electrotransport and deformation model of ion exchange membrane based actuators

A continuum mechanical model of Nafion based metal-polymer actuators is presented. Global integral postulates are written for the conservation of mass, momentum: energy, and charge, Gauss' law, and the second law of thermodynamics. The global equations are then localized in the volume and on the material surfaces bounding the polymer. A finite element formulation is used to predict the evolution of the counter ion concentration, "free" water content, electric potential, and stress/strain during actuation. The model includes stress relaxation phenomena due to water how governed by Darcy's law.