Bistable device using anchoring transition of nematic liquid crystals

The authors have demonstrated a novel bistable memory device writable by a laser beam. The device utilizes the hysteresis of a temperature-driven discontinuous anchoring transition (orientation change) in a dye-doped nematic liquid crystal. The laser light irradiation switches the stable orientation from homeotropic to planar in a liquid crystal on perfluoropolymer surface. The thickness of recorded lines comes down to as low as ∼20 μm. The recorded images were kept at least for a day, i.e., memory effect. We also showed that the temperature range of the hysteresis was lowered down to room temperature using a binary mixture system.