In order to successfully fabricate a commercial Liquid Crystal Display, uniform orientation of the liquid crystal (LC) molecules is required. Traditionally this molecular alignment of liquid crystal is achieved by physically or chemically treating the surface. A simple method used to achieve preferred orientation is rubbing but this may produce dust, static charging and mechanical damage which deteriorates the production yield.
One of the more attractive alternatives to rubbing is the generation of a surface anisotropy of an alignment film by photochemical reaction called “photoinduced alignment”. In general, photoinduced alignment is achieved by exposing with both unpolarized and polarized ultraviolet (UV) light on a photoalignment polymer film.
In this study published under AZojomo*, by Thet Naing Oo, Tetsuya Iwata, Munehiro Kimura and Tadashi Akahane from Nagaoka University of Technology and Core System Co. Ltd, investigated of the surface alignment of liquid crystal multilayers evaporated on a photoaligned polyimide vertical alignment (PI–VA) film was carried out by means of a novel three–dimensional (3–D) surface profiler.
The photoinduced anisotropy of the partially UV–exposed PI–VA film can be visualized as a topological image of LC multilayers. It seems that the topology of LC multilayers indicates the orientational distribution of LC molecules on the treated film. Moreover, it was shown that the surface profiler can be used to produce non–contact images with high vertical resolution (~ 0.01 nm).
It is anticipated that this work will be a considerable aid to the manufacturers of liquid crystal displays (LCDs) across the range of LCD production from televisions to computer screens.
The article is available to view at https://www.azom.com/Details.asp?ArticleID=3058
*AZojomo publishes high quality articles and papers on all aspects of materials science and related technologies. All the contributions are reviewed by a world class panel of editors who are experts in a wide spectrum of materials science. [See https://www.azom.com/Journal%20Editorial%20Board.asp]
AZojomo is based on the patented OARS (Open Access Rewards System) publishing protocol. The OARS protocol represents a unique development in the field of scientific publishing – the distribution of online scientific journal revenue between the authors, peer reviewers and site operators with no publication charges, just totally free to access high quality, peer reviewed materials science. [See https://www.azom.com/azojomo.asp and https://www.azom.com/oars.asp]