Novel Bistable Device Using Anchoring Transition and Command Surface

A light-driven bistable device was fabricated using nematic liquid crystal (NLC) cells with bare glass and perfluoro-polymer (CYTOP) surfaces. The CYTOP surface induces a discontinuous anchoring transition, when a particular NLC (CCN-47) is introduced into the cells. By doping CCN-47 with a small amount of photoisomerizable azo-dendrimer molecules, the bare glass surface serves as a command surface, since the azo-dendrimer is spontaneously adsorbed on the surface. Using hybrid cells with such different surfaces, a homeotropic orientation was successfully converted to a hybrid orientation by very weak ultraviolet-light irradiation. Because of the bistability at a CYTOP surface, the hybrid orientation is retained.