Modeling and simulation of electro‐chemomechanical behavior of ionic polymer‐metal composites within the framework of the Theory of Porous Media

Abstract

Ionic polymer-metal composites (IPMCs) serve as electro-mechanical transducers for actuator and sensor applications, see [1]. Typically, they are sandwiched between two impermeable electrodes comprising the polymer network, the liquid, the fixed anions and the mobile cations. The actuation mechanism takes place by applying an electric potential (voltage) and the mobile cations move towards the cathode. Due to the relocation of the cations (electrostatic and ionic forces), a deformation of the IPMC can be observed. In contrast, the sensing mechanism is performed by applying a mechanical load yielding to a concentration redistribution and generating an electrical potential inside the IPMC. In Leichsenring [2], a parametric study has been carried out for the description of an IPMC. Therein, the Theory of Porous Media (TPM) was used, see [3], while the motion of the liquid and the cations were restricted. In the present contribution, the actuation and sensing behavior of an IPMC is presented within the framework of the TPM, see [5].In order to model the actuation and sensing behavior of an IPMC, the Theory of Porous Media is considered. An IPMC consists of the polymer network ϕ P and the fixed anions ϕ − where both constituents describe the solid phase ϕ S . Furthermore, the overall fluid phase ϕ F contains the liquid ϕ L and the mobile cations ϕ + . Considering the extended balance relations by the electrical quantities within the framework of the TPM, one obtains after some rearrangements the following entropy inequality κ α=1