Variable liquid crystal pretilt angle on patterned surface of LC polymer

• Main Authors: Jun An Huang, 黃君安
• Other Authors: Gwo Mei Wu
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/90970147878401149194

碩士 === 長庚大學 === 光電工程研究所 === 96 === In order to avoid the disadvantages brought forth by the OCB mode, we must skip the stage in which crystal molecules experience a transition from splay configuration to bend configuration. To achieve this effect we managed to control the height of pretilt angles. In an experiment we took horizontal alignment PI to go with vertical alignment LCC (liquid crystal conglomerate). On the surface of this material we produced different patterns of protruding bumps, making use of the special property of polymeric liquid crystal. The patterns were square, triangle and honeycomb respectively. With this processing methodology we successfully controlled the pretilt angles. Tests had shown the pretilt angles were 34°with triangle pattern, 31°with square pattern and 24°with honeycomb pattern, suggesting that different surface patterns would result in considerable changes in pretilt angles measured. And then we changed the concentration of LCC to 5%, 10% and 15%.The results of the experiment showed that variation in concentrations would bring significant changes in pretilt angles. The pretilt angles were 24°with concentration 5%, 61°with concentration 10% and 59°with concentration 15%. The principle that pretilt angles will change when LC is acted by external forces, combined with new processing method, can lead to the effective control over pretilt angles, hence the problems brought by the OCB mode are solved. As a result, the power consummation and response time will decrease.