Bistable cholesteric-blue phase liquid crystal using thermal hysteresis

Abstract The study investigates the thermal hysteresis in the phase transition between the cholesteric liquid crystal and the blue phase of liquid crystal. Both the CLC phase and the blue phase can stably exist at room temperature and be switched to each other using temperature-controlled processes. Two sets of bistable conditions are demonstrated using various surface treatments. In a homogeneous aligned sample, two stable states, CLC with a planar alignment and blue phase with a uniform lattice distribution, reflect light of wavelengths 480–510 nm and 630 nm, respectively, as determined by the corresponding Bragg’s reflection conditions. In the untreated sample, the CLC phase with a focal conic texture can scatter light and the blue phase with a non-uniform lattice distribution provides high isotropic optical transparency.