Enhanced ionic polymer–metal composite actuator with pore size–controlled porous Nafion membrane using silica sol–gel process

Abstract

We fabricated a pore size–controlled porous Nafion membrane using a silica sol–gel process and hydrofluoric acid etching and we developed an enhanced ionic polymer–metal composite actuator using the porous Nafion membrane through the electroless plating and ion exchange procedure. As the pore size of the proposed porous Nafion membrane decreased, the porosity, the water uptake, and the ion exchange capacity increased. Compared with conventional Nafion-based ionic polymer–metal composite actuator, the proposed ionic polymer–metal composite actuator using the porous Nafion membrane with the smallest pore size showed the increased electrical conductivity and displacements of about 122% at the alternating current input (1 V, 0.5 Hz, and 1 Hz) and of about 128% at the direct current input (1 V), as well as an increased blocking force of about 138% at direct current input. The ionic polymer–metal composite actuator that was fabricated by the porous Nafion membrane with the smaller pore size showed better actuation performances.