Influence of water molecule diffusion resistance force on electro-actuating characteristics of ionic polymer-metal

Based on the mechanism of Tadokoro model, the dynamic electro-mechanical response of Ionic polymer-metal composite (IPMC) has been simulated using finite element method. Generally, the water molecule diffusion force is neglected in the most of the former numerical simulation works. In the present paper, the influence of water diffusion resistance force in the process of the movement of sodium ion has been emphatically explored and compared, by introducing two different governing equations: with and without consideration of water diffusion resistance force. The water diffusion resistance force is described as a non-linear term and the corresponding governing equation is solved by iteration. The numerical results show that the water diffusion force has no obvious effect on the displacement, but significant effect on the sodium ion concentration, effective moisture distribution and internal balance force. In addition, the effect exhibits the area selection, especially at the region close to the anode and cathode. The predicting accuracy will be improved by involving this nonlinear component within the governing equation.