Surface induced structures in nematic liquid crystal colloids

TL;DR

This paper theoretically predicts the formation of surface-induced colloidal structures in nematic liquid crystal cells, showing how boundary conditions lead to ordered bulk arrangements like square lattices of quadrupole particles.

Contribution

It introduces a new class of surface-induced colloidal structures in nematic liquid crystals caused by patterned boundary conditions, expanding understanding of director distortions.

Findings

Quadrupole particles form square lattices in NLC cells

Surface patterns induce specific bulk colloidal arrangements

Boundary conditions critically influence colloidal structure formation

Abstract

We predict theoretically the existence of a class of colloidal structures in nematic liquid crystal (NLC) cells, which are induced by surface patterns on the plates of the cell (like cells with UV-irradiated polyimide surfaces using micron size masks). These bulk structures arise from non-zero boundary conditions for the director distortions at the confining surfaces. In particular, we demonstrate that quadrupole spherical particles (like spheres with boojums or Saturn-ring director configurations) form a square lattice inside a planar NLC cell, which has checkerboard patterns on both its plates.