Susumu Hara

TFSI-doped polypyrrole actuator with 26% strain

A polypyrrole film, prepared electrochemically from a methyl benzoate solution of tetra-n-butylammonium bis(trifluoromethanesulfonyl)imide (TBATFSI), showed 26.5% strain and 6.7 MPa stress induced electrochemically in aqueous LiTFSI solution.

Enhancement in electrochemical strain of a polypyrrole–metal composite film actuator

A polypyrrole (PPy)–zigzag metal wire composite film actuator, prepared electrochemically from a methyl benzoate solution of tetrabutylammonium trifluoromethanesulfonate (TBACF3SO3), showed up to 21.4% electrochemical strain, much larger than that (12.8%) of the corresponding PPy–CF3SO3−, driven in aqueous NaPF6 solution.

Fast Response Polypyrrole Actuators with Auxiliary Electrodes

Electrochemical polypyrrole (PPy) actuators, prepared electrochemically from a methyl benzoate solution of tetra-n-butylammonium trifluoromethanesulfonate (TBACF3SO3), have been studied to improve the response rate by two methods; 1) a PPy film attached with plural auxiliary electrodes of thin Au coils, 2) a PPy film equipped with a compliant Au electrode on one side of the film. With increasing the number of auxiliary electrodes for the first method, the film responded faster as if it were a shorter film. These results are due to the decrease in the IR voltage drop along the film from the electrodes and also due to the increased current to the whole film via plural electrodes. The PPy film with the Au thin layer (the second method) exhibited up to 8.8%/s strain rate, which was much faster than that (0.5%/s) without the auxiliary electrodes, keeping the maximum strain of 12–13%. The auxiliary electrodes improved not only the response speed of the PPy actuators but also the durability upon cycling electrochemically.