Electrode of ionic polymer-metal composite sensors: Modeling and experimental investigation

In this study, we theoretically model and experimentally investigate the electrode electrical properties and the mechano-electrical properties of the ionic polymer-metal composite (IPMC) sensor. A physics-based model of the electrode was developed. In addition, based on the Poisson-Nernst-Planck system of equations, the current in the polymer membrane was modeled. By combining the physics of the polymer membrane and the electrode, the model of the surface electrical potential of the IPMC sensor was proposed. Experiments were conducted to test the electrical characteristics of the electrode and validate the model. The results demonstrate that the model can well describe the resistance, capacitance, and surface electrical potential of the IPMC electrode under external oscillation. Based on the model, a parametric study was done to investigate the impact of the parameters on the IPMC electrode properties. The results show that by changing the parameters of the electrode, such as the particle diameter, the electrode thickness, and microstructure, the electrical properties of the electrode can be changed accordingly. The current method of examining the electrode properties may also be applied to the study of electrodes for other smart materials.