Multi-scale modeling of ion transport in high-strain ionomers with conducting powder electrodes

Ionomeric polymer transducers exhibit electromechanical coupling capabilities. The ion transport due to electric stimulus is the primary mechanism of actuation for a class of polymeric active materials known as ionomeric polymer transducers. In this article, a two-dimensional Monte Carlo simulation of ion hopping has been developed to describe ion transport in materials that have fixed and mobile charge similar to the structure of the ionic polymer transducer. Such Monte Carlo simulations were performed to study the influence of conducting powder electrodes on stationary ion distribution in actuation. Ion accumulation around the powder sphere at the cathode is clearly observed in simulation results. Moreover, based on the unique property of stationary charge density of ionomeric polymer transducers in actuation, this article proposed a novel multi-scale model connecting Monte Carlo simulation for the material boundaries and a continuum model for the central part. To validate this multi-scale model, the simulation results are compared with experimental measurements. Both transient and steady-state responses from the experiments show reasonable agreement with those from the multi-scale model.