Dynamics of cholesteric structures in an electric field

TL;DR

This paper investigates how electric fields influence the movement of cholesteric liquid crystal structures, revealing electrohydrodynamic effects as key factors in their drift and rotation behaviors.

Contribution

It introduces a model explaining cholesteric finger drift and rotation under electric fields through electrohydrodynamic effects like charge separation and flexoelectricity.

Findings

Electrohydrodynamic effects explain cholesteric finger drift.

Lehmann-like rotation phenomena are understood via charge separation.

Electric fields induce predictable drift behaviors.

Abstract

Motivated by Lehmann-like rotation phenomena in cholesteric drops we study the transverse drift of two types of cholesteric fingers, which form rotating spirals in thin layers of cholesteric liquid crystal in an ac or dc electric field. We show that electrohydrodynamic effects induced by Carr-Helfrich charge separation or flexoelectric charge generation can describe the drift of cholesteric fingers. We argue that the observed Lehmann-like phenomena can be understood on the same basis.