The fabrication of liquid crystal devices requires a reproducible and accurate method of aligning the LC on the surface of the electrodes. Rubbed polyimide surfaces have been successfully employed but suffer disadvantages. Recent developments in technology have seen new methods based on ion and plasma bombardment, UV exposure and electron irradiation. In addition, there has been much activity in achieving LC alignment through doping of the LC itself with suitable agents. Here, we review the recent developments in LC alignment technology and the patent literature in this area.
Keywords: Liquid crystal, homeotropic, nematic, vertical alignment, pre-tilt angle