Investigation on Novel Polymer Micro/Nanostructured Alignment Thin Films and Their Liquid Crystal Electro-Optical Characteristics

The pretilt angles for the optically compensated bend (OCB) mode liquid crystals have been improved using novel polymer micro- and nano-patterned dual alignment thin film structures in this project. The transition from the splay configuration to the bend configuration can be effectively reduced. The first dual alignment design consisted of a horizontal alignment polyimide (PI) and a patterned vertical alignment liquid crystal polymer (LCP). Three patterning masks have been designed for the photolithography process. The pretilt angles were demonstrated to be increased to 34° for the triangle lattice array-patterned cells, 31° for the square lattice array-patterned cells, and 24° for the honeycomb lattice array-patterned cells The effective control over the pretilt angle could improve the response time to 2 ms when the voltage was ramped up to 5.5 V for the OCB mode liquid crystal devices. In this project, we will continue to increase the nucleation sites and control the pretilt angles by the novel polymer micro- and nano-pattemed alignment structures. A. To study the advanced technologies to increase nucleation sites and the corresponding theoretical mechanisms. B. To design novel polymer micro- and nano-pattemed alignment structures, using excimer laser, plasma, ion beam energy, etc for increasing nucleation sites. C. To assembly unique liquid crystal cells for material structure study, surface analysis, liquid crystal pretilt angle, display evaluation, response time, and electro-optical responses. D. To establish advanced pretilt angle control research analysis, and to propose suitable alignment structures, liquid crystals, and liquid crystal polymers. E. To develop new type multiple layer alignment technologies, or with micro- and nano-stmctures, for stable pretilt angle principles. F. To complete the software simulation of liquid crystal for the novel processes and experimental samples, and to investigate the liquid crystal orientation in microscopic scale.

Project ID:PB9807-2069
External Project ID:NSC98-2221-E182-001