Statistical Properties of Autonomous Flows in 2D Active Nematics

Abstract

We study the dynamics of a tunable 2D active nematic liquid crystal composed of microtubules and kinesin motors confined to an oil-water interface. Kinesin motors continuously inject mechanical energy into the system through ATP hydrolysis, powering the relative microscopic sliding of adjacent microtubules, which in turn generates macroscale autonomous flows and chaotic dynamics. We use particle image velocimetry to quantify two-dimensional flows of active nematics and extract their statistical properties. In agreement with the hydrodynamic theory, we find that the vortex areas comprising the chaotic flows are exponentially distributed, which allows us to extract the characteristic system length scale. We probe the dependence of this length scale on the ATP concentration, which is the experimental knob that tunes the magnitude of the active stress. Our data suggest a possible mapping between the ATP concentration and the active stress that is based on the Michaelis-Menten kinetics that governs motion of individual kinesin motors.

arXiv comment17 pages, 7 figures

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Cited by in corpus (43)

• Topological active matter
• Active Turbulence
• Self-organized dynamics and the transition to turbulence of confined active nematics
• Universal scaling of active nematic turbulence
• Machine learning active-nematic hydrodynamics
• Hydrodynamics of Active Defects: from order to chaos to defect ordering
• Confinement controlled bend instability of three-dimensional active fluids
• Confinement-induced self-organization in growing bacterial colonies
• Extensile to contractile transition in active microtubule-actin composites generates layered asters with programmable lifetimes
• Active boundary layers
• Wrinkling instability in 3D active nematics
• Data-driven discovery of active nematic hydrodynamics
• Predictive local field theory for interacting active Brownian spheres in two spatial dimensions
• Collective dynamics of active Brownian particles in three spatial dimensions: a predictive field theory
• Multiscale Microtubule Dynamics in Active Nematics
• Mesoscopic Simulations of Active-Nematics
• Active extensile stress promotes 3D director orientations and flows
• Shear-induced gelation of self-yielding active networks
• Hydrodynamic theory of $p-$atic liquid crystals
• Orientational correlations in active and passive nematic defects
• Self-mixing in microtubule-kinesin active fluid from nonuniform to uniform distribution of activity
• Effects of confinement on the dynamics and correlation scales in active fluids
• Emerging mesoscale flows and chaotic advection in dense active matter
• Alignment of a topological defect by an activity gradient
• Crowder and Surface Effects on Self-organization of Microtubules
• Scaling regimes of active turbulence with external dissipation
• Flow around topological defects in active nematic films
• Motor crosslinking augments elasticity in active nematics
• Coexistence of defect morphologies in three dimensional active nematics
• Nonlinear spontaneous flow instability in active nematics
• Flow patterns and defect dynamics of active nematics under an electric field
• Fractal generation in a two-dimensional active-nematic fluid
• Analytical model for the motion and interaction of two-dimensional active nematic defects
• Turbulence to order transitions in activity patterned active nematics
• Defect-mediated dynamics of coherent structures in active nematics
• Memory effects, arches and polar defect ordering at the cross-over from wet to dry active nematics
• Aspect-ratio-dependent void formation in active rhomboidal and elliptical particle systems
• Irreversibility in scalar active turbulence: The role of topological defects
• Defect binding-unbinding transition in active nematic membranes
• Dynamical arrest in active nematic turbulence
• Flow coupling between active and passive fluids across water-oil interfaces
• Machine Learning Forecasting of Active Nematics
• Collective epithelial migration mediated by the unbinding of hexatic defects