Polymer actuator based on PVA/PAMPS ionic membrane: Optimization of ionic transport properties

Abstract

In this study, a new ionic network membrane based on blends of water soluble poly (vinyl alcohol) (PVA) and highly ionic conductive poly 2-acrylamido-2-methyl-1-propanesulfonic acid (PAMPS) was synthesized to develop electroactive polymer as artificial muscle. The fabricated ionic polymer–metal composites (IPMCs) membrane actuator in cantilever beam geometry showed a large bending movement (>100°) and maintained curl-up under constant voltage. This property is in sharp contrast with that of IPMC made from Nafion ®. A physically crosslinked ionic network was formed when PVA/PAMPS blend membrane was heat treated at high temperatures above 60 °C. The effect of heat treatment temperature, PVA/PAMPS blend ratio and membrane sample dimension on the electrical and mechanical performance of the resulting IPMC actuator was investigated. The water uptake and ionic conductivity of PVA/PAMPS membrane scale linearly with its ion exchange capacity which in turn is determined by the PVA/PAMPS blend ratio. Optimal blend ratio and sample geometry for the IPMC membrane actuator was obtained to give maximum bending movement and generative blocking force. The mechanical performance of the IPMC actuator is correlated with the transport property of its PVA/PAMPS ionic network membrane.