Verification of Beam Models for Ionic Polymer-Metal Composite Actuator

Ionic Polymer-Metal Composite (IPMC) can work as an actuator by applying a few voltages. A thick IPMC actuator, where Nafion-117 membrane was synthesized with polypyrrole/alumina composite filler, was analyzed to verify the equivalent beam and equivalent bimorph beam models. The blocking force and tip displacement of the IPMC actuator were measured with a DC power supply and Young's modulus of the IPMC strip was measured by bending and tensile tests respectively. The calculated maximum tip displacement and the Young's modulus by the equivalent beam model were almost identical to the corresponding measured data. Finite element analysis with thermal analogy technique was utilized in the equivalent bimorph beam model to numerically reproduce the force-displacement relationship of the IPMC actuator. The results by the equivalent bimorph beam model agreed well with the force-displacement relationship acquired by the measured data. It is confirmed that the equivalent beam and equivalent bimorph beam models are practically and effectively suitable for predicting the tip displacement, blocking force and Young's modulus of IPMC actuators with different thickness and different composite of ionic polymer membrane.