title: Free-surface molecular command systems for photoalignment of liquid crystalline materials.
abstract: The orientation of liquid crystal molecules is very sensitive towards contacting surfaces, and this phenomenon is critical during the fabrication of liquid crystal display panels, as well as optical and memory devices. To date, research has focused on designing and modifying solid surfaces. Here we report an approach to control the orientation of liquid crystals from the free (air) surface side: a skin layer at the free surface was prepared using a non-photoresponsive liquid crystalline polymer film by surface segregation or inkjet printing an azobenzene-containing liquid crystalline block copolymer. Both planar-planar and homoeotropic-planar mode patterns were readily generated. This strategy is applicable to various substrate systems, including inorganic substrates and flexible polymer films. These versatile processes require no modification of the substrate surface and are therefore expected to provide new opportunities for the fabrication of optical and mechanical devices based on liquid crystal alignment.
authors.affiliation: Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Fukuhara
authors.affiliation: Nagoya University Venture Business Laboratory, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603, Japan.
authors.forename: Shusaku
authors.initials: S
authors.lastname: Nagano
authors.affiliation: Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Hara
authors.affiliation: Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Seki