Macroscopic movements of artificial muscles

Summary form only given. A chemomechanical device is a system that can transform chemical energy directly into mechanical work. When the transformation of chemical into mechanical energy is triggered by an electrical signal, we have an electrochemomechanical device. When a conducting polymer film, as polypyrrole, is electrochemically oxidized, positive charges are generated along polymer chains, with inclusion of counterions and solvent. This promotes an increase of volume in conducting polymer. When the polymer is reduced counterions come back from polymer and the volume decreases. We have transformed those molecular movements to macroscopic movements constructing polypyrrole/non conducting polymer multilayers. The change of volume in the conducting film is translated to the non electroactive polymer. An angular movement around the fixed top of the film is described by the bottom of the film during electrochemical redox processes. We report experimental results of electrochemomechanical behaviour of polypyrrole layers in different electrical and chemical conditions. The observed response of the constructed device led to the conclusion that the electrochemomechanical behaviors are essentially controlled by the electrical field and the electrokinetic phenomenon, associated to the movement of ions and solvent in the polymer lattice.