Surface nematic bistability at nanoimprinted topography

The azimuthal nematic bistability was realized by frustration between two azimuthally orthogonal anchoring axes induced by a nanoimprinted groove pattern and mechanical rubbing. The nematic bistability can be explained by the revised Berreman model of groove-induced surface anchoring, recently introduced by Fukuda et al. [Phys. Rev. Lett. 98, 187803 (2007)]. The azimuthal bistability can be tuned in arbitrary direction by changing the groove pitch and rubbing conditions. This simple combinatorial scheme may be considered as a practical candidate for bistable displays with tailored bistable directions required in various liquid crystal device modes.