Effects of grating and photoalignment on nematic liquid crystal alignment using azobenzene polymer

Abstract

The effects of groove and molecular interaction on nematic liquid crystal alignment are studied by using photofabricated surface relief grating and photoinduced alignment. The surface structure and the orientation of liquid crystal were investigated by AFM and polarizing microscope, respectively. In lower grating depth till 182 nm, the easy axis of liquid crystal was found to be parallel to the photoaligned direction. However, the easy axis of liquid crystal begins to change around 252 nm and turns to orient to the grating direction with increasing grating depth, suggesting emergence of the groove effect competing with molecular interaction on liquid crystal alignment.