Modeling of IPMC Cantilever's Displacements and Blocking Forces

The motion of an Ionic Polymer Metal Composite (IPMC) cantilever under a periodic voltage control is modeled. In our finite element 3D model, we follow both the free tip-displacements and the blocking forces for various thicknesses and elastic constants of the ionomer membrane. It turns out that the maximum displacement of the free tip strongly depends on the value of the Young's modulus of the electrodes. Furthermore, the maximum blocking force, F-max, increases with the thickness of the ionomer membrane. At constant values of Young's moduli of the electrodes and ionomer membrane thickness, if the Young's modulus of the ionomer membrane varies within the range from 0.2 MPa to 1 GPa, the change of F-max is less than 10 %. The simulated maximal displacements, blocking forces and electrical currents are compared with the corresponding sets of experimental data, respectively. Qualitative agreement between the simulated and the respective measured data profiles is obtained. Furthermore, it is found that the assumption of electrostatic interactions in the cation depleted region of the ionomer membrane has a negligible effect. The advantage of the model consists in its simplicity.