Memory effects, arches and polar defect ordering at the cross-over from wet to dry active nematics
arXiv:2010.04200 · doi:10.1039/D0SM01794A
Abstract
We use analytic arguments and numerical solutions of the continuum, active nematohydrodynamic equations to study how friction alters the behaviour of active nematics. Concentrating on the case where there is nematic ordering in the passive limit, we show that, as the friction is increased, memory effects become more prominent and topological defects leave increasingly persistent trails in the director field as they pass. The trails are preferential sites for defect formation and they tend to impose polar order on any new defects. In the absence of noise and for high friction, it becomes very difficult to create defects, but trails formed by any defects present at the beginning of the simulations persist and organise into parallel arch-like patterns in the director field. We show aligned arches of equal width are approximate steady state solutions of the equations of motion which co-exist with the nematic state. We compare our results to other models in the literature, in particular dry systems with no hydrodynamics, where trails, arches and polar defect ordering have also been observed.
References in corpus (36)
- The Mechanics and Statistics of Active Matter
- Spontaneous motion in hierarchically assembled active matter
- Meso-scale turbulence in living fluids
- Hydrodynamic fluctuations and instabilities in ordered suspensions of self-propelled particles
- How far from equilibrium is active matter?
- Topology and Dynamics of Active Nematic Vesicles
- Fluid dynamics of bacterial turbulence
- Pressure is not a state function for generic active fluids
- Direct measurement of the flow field around swimming microorganisms
- Fluid Flows Created by Swimming Bacteria Drive Self-Organization in Confined Suspensions
- Pressure and Phase Equilibria in Interacting Active Brownian Spheres
- Defect annihilation and proliferation in active nematics
- Active nematics on a substrate: giant number fluctuations and long-time tails
- Orientational order of motile defects in active nematics
- Flocking at a distance in active granular matter
- Adaptive locomotion of artificial microswimmers
- Phototaxis of synthetic microswimmers in optical landscapes
- Defect dynamics in active nematics
- Patterning active materials with addressable soft interfaces
- Turbulent dynamics of epithelial cell cultures
- Stabilization of active matter by flow-vortex lattices and defect ordering
- Taming active turbulence with patterned soft interfaces
- Active Particles Bound by Information Flows
- Defect unbinding in active nematics
- Active vs. Passive Hard Disks Against a Membrane : Mechanical Pressure and Instability
- Statistical Properties of Autonomous Flows in 2D Active Nematics
- Entropy Production Rate is Maximized in Non-Contractile Actomyosin
- Relating microswimmer synthesis to rheotactic tunability
- Spontaneous mirror-symmetry breaking induces inverse energy cascade in 3D active fluids
- Actively crosslinked microtubule networks: mechanics, dynamics and filament sliding
- Negative stiffness and modulated states in active nematics
- Antipolar ordering of topological defects in active liquid crystals
- Understanding dense active nematics from microscopic models
- Active nematics with anisotropic friction: the decisive role of the flow aligning parameter
- Pair creation, motion, and annihilation of topological defects in 2D nematics
- Maximal fluctuations of confined actomyosin gels: dynamics of the cell nucleus