title: Photo-configurable embossed liquid crystal alignment layer with high azimuthal anchoring strength.
abstract: Herein we describe a photo-alignment layer of improved azimuthal anchoring energy comparable to conventional rubbing method. In order to address the inherent low anchoring stability of photo-alignment layer, we applied embossing technique to conventional photosensitive polymer film, based on the cinnamoyl photoreactive groups, to introduce physical micro-groove effect for additional anchoring energy. From this, 2.5 × 10⁻⁴ J/m² of azimuthal anchoring energy was achieved, which is considered as synergistic effect from both photoinduced chemical interaction and physical microgroove alignment. In this study, we conducted systematic study on change in anchoring energy as a function of both aspect ratio of embossed pattern and UV exposure dose. We also demonstrated fabrication of sophisticated multi-domain structure of LC cells and discussed theoretical interpretation through LC simulation.
authors.affiliation: Department of Chemical and Biomolecular Engineering, KAIST, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701, South Korea.
authors.forename: Dowon
authors.initials: D
authors.lastname: Ahn
authors.forename: Yong-Cheol
authors.initials: YC
authors.lastname: Jeong
authors.forename: Manhee
authors.initials: M
authors.lastname: Han
authors.forename: Kuk Young
authors.initials: KY
authors.lastname: Cho
authors.forename: Seungsup
authors.initials: S
authors.lastname: Lee
authors.forename: Jung-Ki
authors.initials: JK
authors.lastname: Park
mesh_terms: D016880:Anisotropy; D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D008027:Light; D050866:Liquid Crystals / Q000737:chemistry* / Q000528:radiation effects*; D008420:Manufactured Materials; D008422:Materials Testing; D008956:Models, Chemical