Shape-Controlled Colloidal Interactions in Nematic Liquid Crystals

Abstract

Hairy Polygon Solution: The packing of rods on the surface of a sphere leads to packing defects at the opposite poles. It is, however, possible to flat-pack rods onto a torus. This topological problem is well known as the hairy ball theorem, and arises when you place spherical particles inside a nematic liquid crystal. Lapointe et al. (p. 1083 ) considered the packing of liquid crystal molecules onto lithographically fabricated polygons and found that the number of dipoles that formed depended upon whether the polygon had an odd or even number of sides. The defect structures were attracted to each other, such that the liquid crystal could pull together the particles in a form of controlled self-assembly.