Periodic reverse-twist nematic domains obtained by microrubbing patterns

A method for forming periodic 90° reverse-twist domains using a microscale rubbing pattern has been proposed; that is, an isolated 90° twist domain is surrounded by a 45° twist domain. Since liquid crystal (LC) materials exhibit elastic nature, the twist sense of the inner 90° twist domain prefers to be the same as that of the surrounding 45° twist domain. Two factors are investigated to obtain periodic 90° reverse-twist domains; (i) the injection process of LC material (isotropic or nematic phase) and (ii) the ratio of the area of the surrounding 45° twist domain and the whole area (the normalized area of the 45° twist domain). In the case of the injection in isotropic phase, it is revealed that periodic 90° reverse-twist domains can be obtained only when the area of the 45° twist domain is sufficiently large. On the other hand, in the case of injection in nematic phase, periodic 90° reverse-twist domains can successfully obtained regardless of the area of the 45° twist domain. Thus, the injection rocess...