IPMC frequency dependent multiphysics model considering electrodes high surface and fractional effects

Ionic Polymer Metal Composites (IPMCs) are electroactive polymers which can be used both as sensors and as actuators. The IPMC white box modelling requires several parameters, not always accessible via theoretical approaches or experimentation. This work addresses such an issue by exploiting a frequency domain model optimization procedure which integrates Nelder-Mead simplex method with the COMSOL Multiphysics^® models. It uses experimental data and fitting model simulations for microscopic parameters´ identification. The proposed model integrates the effect of the high surface area electrodes by including a varying-along-the-thickness relative permittivity ε_R. Moreover, as an original contribute to IPMC studies, a fractional order dynamics has been identified in the white-box model, confirming previous studies on IPMC grey box model and on electro-active polymeric devices. The model shows adherence with recorded data, identifying the second order-like dynamics in the frequency response.