Flow patterns and defect dynamics of active nematics under an electric field

TL;DR

This study numerically explores how electric fields influence flow patterns and defect behaviors in active nematics, revealing anisotropic turbulence, defect localization, and dynamic state transitions.

Contribution

It introduces a detailed numerical analysis of electric field effects on active nematics, highlighting anisotropic turbulence and defect dynamics not previously characterized.

Findings

Electric fields induce anisotropic active turbulence.

Defects become localized with characteristic creation dynamics.

Periodic oscillations occur between laning and turbulent states.

Abstract

The effects of an electric field on the flow patterns and defect dynamics of two-dimensional active nematics are numerically investigated. We found that field-induced director reorientation causes anisotropic active turbulence characterized by enhanced flow perpendicular to the electric field. The average flow speed and its anisotropy are maximized at an intermediate field strength. Topological defects in the anisotropic active turbulence are localized and show characteristic dynamics {with simultaneous creation of} two pairs of defects. A laning state characterized by stripe domains with alternating flow directions is found at a larger field strength near the transition to the uniformly aligned state. We obtained periodic oscillations between the laning state and active turbulence, which resembles an experimental observation of active nematics subject to anisotropic friction.