Anisotropic actuation of mechanically textured polypyrrole films

Free-standing polypyrrole films have been stretched or cold rolled to produce uniaxially and biaxially textured films. The oriented films show an increase in conductivity up to 3× when compared to unprocessed films, due to polymer chain alignment. Highly anisotropic active stress and strain are observed for the textured films, with up to 7× larger active strains transverse to the orientation direction. This anisotropy results in a 100% increase in active stress and 70% increase in active strain when compared to unprocessed films, and active strains over 10% (when cycled at 0.1 V/s) have been achieved with this method.