Competition of elasticity and flexoelectricity for bistable alignment of nematic liquid crystals on patterned substrates

摘要

We show that patterned surfaces can promote bistable configurations of nematics for reasons other than thensymmetry of the surface. Numerical and analytical calculations reveal that a nematic liquid crystal in contactnwith a striped surface is subject to the competing aligning influences of elastic anisotropy, differing energy costnof various types of deformation, and flexoelectricity, curvature-induced spontaneous polarization. These effectsnfavor opposing ground states where the azimuthal alignment is, respectively, parallel or perpendicular to thenstripes. Material parameters for which the effect might be observed lie within the range measured for bent-corennematogens.