A simple and reliable method for measuring the liquid crystal anchoring strength coefficient

Abstract

By measuring the electric Fréedericksz transition threshold in a wedged capacitance cell, we have developed a simple method for determining the anchoring strength coefficient for tilt of the director relative to the substrate normal. This technique requires neither a knowledge of the absolute cell thickness nor a knowledge of the optical birefringence. Moreover, it applies to both the homeotropic orientation for Δχ < 0, and to the planar orientation for Δχ > 0, where Δχ is the dielectric susceptibility anisotropy.