Molecular mechanism of ionic electroactive polymer actuators

The movement of ionic electroactive polymer actuators utilizes their anisotropic volume change, which is induced by the applied voltage. The mechanism of the volume change is, however, not well understood, especially at the molecular level. In this paper, we first review the present understanding of the mechanism of the volume change at the molecular level, focusing on the actuators made with carbon materials. Then we discuss the pressure generated in the actuators in response to the applied voltage based on the results of the Monte Carlo simulation. We show that the mechanism of the actuators can be analyzed at the molecular level in terms of the balance between the electrostatic and volume exclusion interactions that act among the electrode materials and the electrolyte ions.