Bending machine using anisotropic polypyrrole films

A method to prepare large-size anisotropic polypyrrole (PPy) film using a slab vessel consisting of PTFE walls as well as its actuation properties bas been reported. The PPy film can be grown along one side of the PTFE walls and has a morphological anisotropy along thickness. A piece of its bends and reverts in a regular direction during a redox cycle without any other processes such as lamination. The actuation characteristics of the anisotropic PPy film strongly depend on the size of cation in the driving electrolyte. The bending of this actuator at the room temperature becomes slower for large cations. The temperature dependence of characteristics of the anisotropic PPy film as actuators has been investigated. The arrival time of actuator becomes shorter in all electrolyte solution with increasing temperature. This can be understood in terms of the thermally activated microscopic movement of polymer chains. It is also found that this actuator can lift an object which weighs more than 25 times of the weight of actuator itself.