Process Design and Fabrication of Sample for Non-contact Liquid Crystal Alignment with High Yield

• Published in: Journal of electrical engineering & technology Vol. 15; no. 1; pp. 79 - 83
• Main Authors: Seo, Min-kyu, Han, Jeong-min, Shon, Jin-geun
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 2020; 대한전기학회
• Subjects: Electrical Engineering; Electrical Machines and Networks; Electronics and Microelectronics; Engineering; Instrumentation; Original Article; Power Electronics; 전기공학; Non-contact liquid crystal alignment process; Atomic force microscopy; Alignment film; Liquid crystal
• ISSN: 1975-0102; 2093-7423
• DOI: 10.1007/s42835-019-00270-2

In this study, we report the results of an experiment for aligning liquid crystals (LCs) by irradiating ultraviolet rays that are not polarized to an alignment layer, and a simulation result on the alignment principle. In the case of irradiating un-polarized ultraviolet rays to the substrate coated with the alignment film, there have been many experimental reports on the alignment mechanism of the LC due to the anisotropy generated in the substrate, but the theoretical approach is somewhat lacking. As a result of the experiment, the best orientation was observed at around 45°. As a result of the simulation, it was found that the maximum difference between the p-polarization and the s-polarization was within the range of similar angles there was. The theoretical approach to the alignment mechanism of LC was possible. And we have experimentally confirmed that the mechanism of liquid crystal alignment by conventional Groove theory is possible by irradiation of unpolarized UV light. The AFM analysis confirmed that the surface anisotropy that causes this orientation principle actually occurs in the unpolarized UV light. It is expected that this non-contact orientation method can realize higher production yield than the conventional contact type rubbing method, and the result of this study could contribute to the improvement of the yield.