Isaac Newton Institute for Mathematical Sciences

Donuts and twist: Cholesteric liquid crystals confined in toroidal droplets

Presenter: Ana Fialho (Centro de Física Teórica e Computacional, Departamento de Física, Universidade de Lisboa)

Co-authors: Nuno M. Silvestre (Centro de Física Teórica e Computacional, Departamento de Física, Universidade de Lisboa), Nelson R. Bernardino (Centro de Física Teórica e Computacional, Departamento de Física, Universidade de Lisboa)

Abstract

We study the director field textures of a cholesteric liquid crystal confined by a toroidal surface. When a liquid crystal is enclosed into droplets, its ground state is a result of the competition between elasticity and the geometrical, and topological, constraints imposed by the confinement. The behaviour of a liquid crystal encapsulated by spherical surfaces is already well documented, and uniform-to-twisted orientational transitions have been observed for 8CB droplets. New experimental techniques allow the generation of higher genus domains, such as torus. For nematic toroidal droplets, the interplay between the elastic anisotropy, the geometry and the topology of the domains promotes a twisted configuration with no defects. Here, we study how the chirality affects the orientational configuration of cholesteric toroidal drops, and how it relates to the geometry and topology of the domains.