Polymer-stabilized reflective fingerprint cholesteric texture grating

This study describes a reflective grating. It is fabricated using a simple process consisting of thermal annealing followed by UV irradiation through a grating photomask. The sample is made from a mixture of cholesteric liquid crystal and prepolymer materials. A cholesteric liquid crystal has a planar texture, which changes under an applied external field, thus forming the electrically switchable reflective grating. The multistability of the grating can be achieved by applying various voltage pulses; the memory effect of the grating's gray-scale persists for two months. The high switching contrast ratio and fast response of the grating are also discussed.