All-electrical switching and electrothermo-optical response of a tristable smectic-A liquid crystal

A unique switching mechanism in the smectic-A (SmA*) phase involving textural change between any two among the planar, homeotropic and focal conic states is investigated. Exploiting the temperature-dependent textural transition characteristics of a SmA* liquid crystal (LC), we proposed a multi-stable switching scheme relying on AC voltage to induce the dielectric effect and pseudo-dielectric heating. This mechanism exhibits desirable properties for LC cells with anti-parallel planar surface treatment. Compared with the electrical operation mode of conventional SmA devices, the optical states enabled by this approach show superior qualities in both transmittance and haze value. The revealed features, including the in-phase switching, tunable operating temperature and excellent optical performance, show great potential for applications in smart glass and other energy-saving devices.