title: Liquid crystal orientation transition on microtextured substrates.
abstract: A uniform alignment of liquid crystal (LC) with finite pretilt was observed on microtextured substrates that were lithographically fabricated with alternating horizontal and vertical corrugations. As the period of alternation was decreased toward 0.8 microm, the nematic LC alignment on these substrates changed from inhomogeneous in plane, copying the substrate corrugations, to a uniform configuration with a large pretilt of approximately 40 degrees. This transition is pertinent to a frustrated boundary wherein a lowering in the LC elastic energy due to spatial variation in the LC orientation compromises an increase in the surface anchoring energy. A model based on this idea demonstrates good agreement with the experiment. This result may open up a new arena for tailoring substrate characteristics for LC alignment.
authors.affiliation: Department of Physics and Institute of Nano Science and Technology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Baoshe
authors.initials: B
authors.lastname: Zhang
authors.forename: Fuk Kay
authors.initials: FK
authors.lastname: Lee
authors.forename: Ophelia K C
authors.initials: OK
authors.lastname: Tsui
authors.forename: Ping
authors.initials: P
authors.lastname: Sheng