Polypyrrole films with anisotropy for artificial muscles and examination of bending behavior

The novel features of electrochemical actuators fabricated from a cylindric al polypyrrole (PPy) pipe prepared by the electrochemical polymerization te chnique have been described. This cylindrical PPy pipe was cut into a recta ngular film and its electrochemical and electrical properties were measured . When the inner surface of the PPy film (surface in contact with electroly te when PPy was polymerized) was insulated and redux was carried out, the P Py film bent toward the outer surface (surface in contact with a slender Te flon pipe when PPy was polymerized) upon reduction and returned to its orig inal shape upon oxidation. However, the bending was not completely accompli shed by redox when rhc outer wall side of the PPy film was insulated. Altho ugh such an anomalous bending in the PPy-film actuator cannot be explained satisfactorily at this stage, we speculate that the bending phenomena are d ue to the difficulty of dopant transfer between inner and outer surfaces.