Preparation of gold-solid polymer electrolyte composites as electric stimuli-responsive materials

The construction of an electromechanical. actuator with large displacement, with fast time response, and without electrolytic gas evolution in pure wa ter or saline is described. Improvement in the previously reported platinum -polymer electrolyte membrane composite was made by switching to gold, depo sited by the "impregnation-reduction method", using cationic gold complexes and reducing agents. The gold-composite actuator showed larger displacemen ts than the platinum composite at the same voltage and at lower loading. In addition, no gas evolution occurred up to the maximum applied voltage [>2. 0 V], due to the much higher overvoltage for hydrogen and oxygen evolution on gold.