Conducting polymer soft actuators based on polypyrrole films

Electrochemomechanical deformation (ECMD) of a conducting polymer, polypyrrole (PPy) has been studied to attain better performance as soft actuators. The PPy films were electrochemically prepared from methyl benzoate solution of tetra butyl ammonium (TBA) trifluoromethansulfonate, TBACF(3)SO(3) and TBA bis(perfluoroalkylsufonil)imid, TBA(CnF2n+1SO2)(2) N) (n = 1 - 4). The PPy films prepared from TBACF3SO3 are tough and flexible with the conductivity of more than 100 S/cm, and characterized as large force muscle with maximum stress of 49MPa. On the other hand, the PPy films obtained from TBA(CnF2+1SO2)(2) N were porous and gel in wet, and characterized as large contraction ratio muscle with the strain of 39% at the maximum. The maximum contraction ratio and force are more than those of natural muscles. The energy conversion efficiency of the electrical input to mechanical output has been estimated under the application of load. It has been found that during contraction of the film 0.2-0.25% of input electrical energy was utilized for the mechanical work as the output.