Unidirectional Homogenous Alignment of Smectic Liquid Crystal under Shear Stress

Homogenous alignment of smectic liquid crystal is demonstrated by applying bidirectional shear with controlled amplitude and frequency. For shear amplitudes smaller than 10 μm and at the frequency of 100Hz, the smectic layer was found to align in the direction of shear. The quality of alignment was evaluated from the contrast ratio obtained when the sample was placed between crossed polarizers and set at 0° and 45° to the transmission axes. A monotonic increase in the alignment quality was found with increasing shear amplitude.