Free-standing polypyrrole actuators with response rate of 10.8% s-1

A free-standing polypyrrole (PPy) film actuator without any additional electrode or metal backing, prepared electrochemically from an aromatic ester solution of tetra-n-butylammonium bis(trifluoromethanesulfonyl)imide (TBATFSI), exhibited up to 29% electrochemical strain, and a peak response rate of 10.8% s(-1) in an H2O/propylene carbonate (PC) solution of LiTFSI. This is the very first time both large electrochemical strains and fast response rates were achieved in the conducting polymer actuators. The large and fast electrochemical deformation resulted from the fact that the PPy film doped with large TFSI anions swelled in PC such that TFSI can insert and expel the PPy film easily, and that a high ionic conductivity in H2O/PC solution enabled to move TFSI quickly. (c) 2005 Elsevier B.V. All rights reserved.