Generation of pretilt angles in a nematic liquid crystal by transcription alignment on polyimide surfaces

Pretilt angle generation in a nematic liquid crystal (NLC) by a transcription alignment technique, as used for non-rubbed polyimide (PI) surfaces with side chain, has been investigated. Monodomain alignment of the NLC in cells fabricated by transcription alignment on a PI surface was observed. The generated pretilt angle of the NLC is about 3.7 degrees; it decreases with increasing rubbing time of the original substrate. It is considered that the generation of the NLC pretilt angle may be attributed to steric interaction due to the polymer side chain. It is also suggested that the LC alignment produced by the transcription alignment technique is attributable to a memory effect of the NLC on the PI surfaces.