Second Order Elasticity and Critical Thickness of Hybrid Aligned Nematics Strongly Anchored on the Planar Side

Abstract

The second order bulk elastic constants, characterizing the squares of second order derivatives of the director, deeply influence the behavior of weakly anchored nematics. Here the critical thickness of a Hybrid Aligned Nematic cell, strongly anchored on the planar side, is calculated as a function of the anchoring strength at the homeotropic side, of the mixed splay-bend, and of the second order bulk elasticity.