title: Reconfigurable Photonic Capsules Containing Cholesteric Liquid Crystals with Planar Alignment.
abstract: Cholesteric liquid crystals (CLCs) reflect selected wavelengths of light owing to their periodic helical structures. The encapsulation of CLCs leads to photonic devices that can be easily processed and might be used as stand-alone microsensors. However, when CLCs are enclosed by polymeric membranes, they usually lose their planar alignment, leading to a deterioration of the optical performance. A microfluidics approach was employed to integrate an ultrathin alignment layer into microcapsules to separate the CLC core and the elastomeric solid membrane using triple-emulsion drops as the templates. The thinness of the alignment layer provides high lubrication resistance, preserving the layer integrity during elastic deformation of the membrane. The CLCs in the microcapsules can thus maintain their planar alignment, rendering the shape and optical properties highly reconfigurable.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 (Korea).
authors.forename: Sang Seok
authors.initials: SS
authors.lastname: Lee
authors.affiliation: Center for Advanced Functional Polymers, Korea Research Institute of Chemical Technology, Daejeon, 305-600 (Korea).
authors.forename: Su Kyung
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Center for Advanced Functional Polymers, Korea Research Institute of Chemical Technology, Daejeon, 305-600 (Korea).
authors.forename: Jong Chan
authors.initials: JC
authors.lastname: Won
authors.affiliation: Center for Advanced Functional Polymers, Korea Research Institute of Chemical Technology, Daejeon, 305-600 (Korea).
authors.forename: Yun Ho
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 (Korea). kim.sh@kaist.ac.kr.
authors.forename: Shin-Hyun
authors.initials: SH
authors.lastname: Kim
keywords: emulsions; liquid crystals; microcapsules; microfluidics; photonic devices