Abstract
A polypyrrole (PPy) film electrochemically grown in a thin slab vessel consisting of poly(tetrafluoroethylene) (PTFE) walls, exhibits a notable anisotropy along the thickness. This anisotropy allows it to bend in a regular direction upon electrochemical undoping and reverts upon doping. In this paper, the size effect, i.e., the length dependence of reduction current, of the actuator has been studied. The length was changed by trimming the tip of the actuator which was initially soaked for 12 mm in the electrolyte. It has been clarified that the current saturates when the actuator exceeds a certain length. This may reflect the reduction of conductivity of PPy upon undoping, which makes the tip of actuator almost be insulated from the power source. It is also found that the width of actuator and the electrolyte do not influence on the size effect.
