Electrochemical muscles: Micromachining fingers and corkscrews

Millimeter‐scale polymer “fingers” are reported, in which the volume changes of the conjugated polymer polypyrrole that occur in response to electrochemical reduction or oxidation are used to create electrically controlled mechanical actuators. The short bilayer gold and polypyrrole fingers in the Figure can be made to curl by reducing the polypyrrole. The primitive fabrication technique used to make these fingers points the way to the microminiaturization of these artificial muscles. magnified image