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. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]