(27b) Particle-Wavy Wall Interactions in a Nematic Liquid Crystal

We are developing strategies for directed assembly for particles in nematic liquid crystals (NLCs), in which elastic energy fields and topological constraints provide a rich landscape for structure formation. NLCs are comprised of elongated molecules that co-align to minimize their free energy; deviations from this co-alignment are costly. Thus, these systems are sensitive to boundary topography and colloidal inclusions. By confining a NLC near a wavy wall with homeotropic (perpendicular) anchoring and a given wavelength, we distort the NLC director field, and impose well defined zones of bend and splay that decay over distances comparable to the wavelength. A colloid with well-defined anchoring, placed within this director field, migrates and docks in preferred locations that depend on the nature of the colloid’s anchoring, and its defect structure. We examine several aspects of the particle wall interaction for colloids, including metastable and stable states. Strategies to harness this landscape for preferred docking sites, structure formation and control are discussed.