Controlled local organization of lyotropic liquid crystalline polymer thin films with electric fields

Abstract

The ability of electric fields to induce the controlled alignment of lyotropic liquid crystalline polymer thin films on microfabricated substrates is demonstrated. These devices allow for variations in electric field geometry on the polymer alignment to be examined systematically. The polymers studied included poly(hexyl isocyanate) (PHIC) and poly(benzyl l-glutamate). The polymers were oriented by the electric field while in solution and solidified into a stable, oriented structure by solvent evaporation. Optical microscopy and transmission electron microscopy experiments make it possible to directly image the disclinations that mediate molecular alignment. The defect type and density in the solidified films are a function of the electric field geometry.