Development of ionic polymer metal composite actuator by EB graft-polymerization

Ionic polymer-metal composites (IPMC) actuators were fabricated by applying ionic exchange groups such as sulfonic acids and carboxylic acids using EB graft-polymerization to two types of fluorine-based copolymers (Poly (tetrafluoroethylene-co-hexafluoropropylene): FEP and Poly (ethylene-co-tetrafluoroethylene): ETFE) as base materials, and then forming electrodes with Pt-Pd by sputtering. The physical properties of the obtained graft membrane and the evaluation as an actuator were performed. It was suggested that the acrylic acid graft membrane is preferable for PEM as components of IPMC actuator, because the ion conduction mechanism is a vehicle mechanism in which oxonium ions pass through formed hydrated clusters in PEM. In the case of operation at 10 V, IPMC actuator based on the acrylic acid-grafted FEP and ETFE showed similar or larger displacement than that based on conventional membrane. The grafted ETFE, which has high mechanical properties, is superior to the grafted FEP used in the actuators. Therefore, it was found that the ETFE grafted with acrylic acid is preferable for the IPMC actuator.