Switchable optical polarizer based on electrochromism in stretch-aligned polyaniline

We report on the polarizing electrochromic (EC) effect of a conjugated polymer. This has been achieved in a planar flexible electrochemical device cell comprised of a patterned stretch-aligned thin film of polyaniline and an electrolyte, all made on a polyethylene foil substrate. The resulting device exhibits polarized absorption characteristics, of a dichroic ratio of 4, that can be controlled by the voltage applied. Also, thin flexible EC polarizers have been realized by combining two stretch-aligned polyaniline films with orthogonal stretching direction. In the resulting EC polarizer the orientation of the polarized absorption can be switched between two orthogonal directions, depending on the voltage applied. (C) 2003 American Institute of Physics.