Polypyrrole Actuator Operating Characteristicsin Electrolyte Solution Mixed with Methanol

Abstract

In this work, a PPy actuator was fabricated by galvanostatic electropolymerization. The electrochemical deformation behaviors of the PPy actuator were investigated in aqueous solutions of an electrolyte, lithium bis(trifluoromethanesulphonyl)imide (LiTFSI), containing different concentrations of methanol. Marked improvement of the actuating strain of approximately 9% was achieved when the actuator was driven by a potential between –1 and 1 V in the LiTFSI electrolyte containing 40 to 50% of methanol under a load stress of 0. 3 MPa. On the other hand, the actuator functioned in the electrolyte solutions containing more than 60% of methanol showed rapid decrease of the actuating strain and the electrochemical creep after repeated actuations. Possible mechanisms for these behaviors were discussed.