Rubbed Polyimide Thin Films for Zigzag Free Surface Stabilized Ferroelectric Liquid Crystal

Abstract

We investigate the effects of rubbing on the surface free energies of polyimide thin films, and how the surface energetic properties influence the molecular alignment of ferroelectric liquid crystals and the formation of zigzag defects. Rubbing breaks the uniformity in free energy at the surface of polyimide thin film. By properly rubbing the polymer, a diminishment of the difference between the polar part of the surface energies along and against the rubbing direction, respectively, can be achieved, and will favour the formation of zigzag free ferroelectric liquid crystal layer.

Keywords:

• chevron structure
• ferroelectric liquid crystal
• liquid crystal alignment
• rubbed polyimide
• zigzag lines

Acknowledgments

The authors acknowledge the financial support from NSC of Taiwan through project NSC962221E110042 and the “Aim for Top Universities Plan” funded by NEC of Taiwan.