Activity driven orientational order in active nematic liquid crystals on an anisotropic substrate

Abstract

We investigate the effect of an anisotropic substrate on the turbulent dynamics of a simulated two dimensional active nematic. This is introduced as an anisotropic friction and an effective anisotropic viscosity, with the orientation of the anisotropy being defined by the substrate. In this system we observe the emergence of global nematic order of topological defects that is controlled by the degree of anisotropy in the viscosity and the magnitude of the active stress. No global defect alignment is seen in passive liquid crystals with anisotropic viscosity or friction confirming that ordering is driven by the active stress. We then closely examine the active flow generated by a single defect to show that the kinetic energy of the flow is orientation dependent, resulting in a torque on the defect to align them with the anisotropy in the substrate.

5 pages, 4 figures

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Cited by in corpus (7)

• Active nematics with anisotropic friction: the decisive role of the flow aligning parameter
• Defect Spirograph: Dynamical Behavior of Defects in Spatially Patterned Active Nematics
• Orientational correlations in active and passive nematic defects
• Relations between angular and Cartesian orientational expansions
• Properties of twisted topological defects in 2D nematic liquid crystals
• Defect order in active nematics on a curved surface
• Orientational order parameters for arbitrary quantum systems