Shaping Boundaries to Control and Transport Topological Defects in Colloidal Nematic Liquid Crystals

TL;DR

This paper demonstrates how boundary topography can be used to control and manipulate topological defects in colloidal nematic liquid crystals, enabling defect transport and potential information storage applications.

Contribution

It introduces a novel method of controlling defect states in colloidal nematics through boundary patterning and dynamic shape-shifting, extending control beyond molecular systems.

Findings

Topographical boundary patterning controls defect configurations.

Dynamic boundary shaping enables defect transformation and transport.

Boundary design facilitates liquid crystal-based information storage.

Abstract

Anisotropic rod-like particles form liquid crystalline phases with varying degrees of orientational and translational order. When confined geometrically, these phases can give rise to topological defects, which can be selected and controlled by tuning how the rods align near boundaries, known as anchoring. While anchoring in molecular liquid crystals can be controlled through surface functionalization, this approach is not easily applicable to microscale colloidal systems, which have so far been limited to planar anchoring. Here, using particle-based simulations, Landau-de Gennes theory, and experiments on colloidal rods, we demonstrate that topographical patterning of the boundary can effectively control the anchoring type and, in turn, the defect state in two-dimensional confined nematics. Building on this, we show that dynamically shape-shifting the boundaries can transform and transport topological defects, enabling the design of liquid crystal analogs for binary information storage.