Liquid Crystal Alignment on Polymer Films

Abstract

The rubbed polyimide (PI) and PI LB films were fabricated and treated to align the nematic liquid crystal (LC) 5CB. The rubbed polyimide (PI) films aligned LC cell shows a higher LC pretilt angle than the cell aligned by PI LB films. Atomic force microscope (AFM) observations indicate that the rubbed PI films have a needle-like structure, while PI LB films have a groovy structure. We think that the needle-like structure plays a major role in producing the higher LC pretilt angle.