Controlling motile disclinations in a thick nematogenic material with an electric field

TL;DR

This study explores how electric fields influence the behavior of topological disclinations in nematic materials, revealing methods to control defect networks for designing advanced materials.

Contribution

It introduces the concept of fluctuating electronematics to control disclination kinetics and topology in nematic materials using electric fields, advancing defect engineering.

Findings

Electric flux lines are highly non-uniform below the Fréedericksz threshold.

Electric field slows down disclination line kinetics.

Dielectric anisotropy influences disclination filtering and asymmetry.

Abstract

Manipulating topological disclination networks that arise in a symmetry-breaking phase transfor- mation in widely varied systems including anisotropic materials can potentially lead to the design of novel materials like conductive microwires, self-assembled resonators, and active anisotropic matter. However, progress in this direction is hindered by a lack of control of the kinetics and microstructure due to inherent complexity arising from competing energy and topology. We have studied thermal and electrokinetic effects on disclinations in a three-dimensional nonabsorbing nematic material with a positive and negative sign of the dielectric anisotropy. The electric flux lines are highly non-uniform in uniaxial media after an electric field below the Fr\'eedericksz threshold is switched on, and the kinetics of the disclination lines is slowed down. In biaxial media, depending on the sign of the dielectric anisotropy, apart from the slowing down of the disclination kinetics, a non-uniform electric field filters out disclinations of different topology by inducing a kinetic asymmetry. These results enhance the current understanding of forced disclination networks and establish the pre- sented method, which we call fluctuating electronematics, as a potentially useful tool for designing materials with novel properties in silico.