Director configurations of a nematic microdroplet in a ferroelectric medium

Abstract

Micron-scale droplets of nematic liquid crystal, embedded in a solid polymer matrix, are the active conponents of polymer dispersed liquid crystal (PDLC) shutters. An electric field is used to orient the director fields in PDLC droplets and thereby control the transmission of light through the film. We have calculated the director configurations of PDLC droplets dispersed in a ferroelectric matrix, which could be used to stabilize the oriented state. Our approach is based on the Landau-de Gennes model free energy and determines the stable configuration by numerical solution of the Euler-Lagrange equations for the director field. Unlike earlier work on this subject, we take into explicit account the effects of spatial variations in the electric field that arise due to the liquid crystal's anisotropic polarizability. We find that these inhomogeneities are significant in determining the stable director configuration, and predict a greater range of stability for the radial phase than that obtained using the uniform-field approximation.