Dynamical patterns in active nematics on a sphere

Abstract

Using agent-based simulations of self-propelled particles subject to short-range repulsion and nematic alignment we explore the dynamical phases of a dense active material confined to the surface of a sphere. We map the dynamical phase diagram as a function of curvature, alignment strength and activity and reproduce phases seen in recent experiments on active microtubules moving on the surfaces of vesicles. At low driving, we recover the equilibrium nematic ground state with four +1/2 defects. As the driving is increased, geodesic forces drive the transition to a band of polar matter wrapping around an equator, with large bald spots corresponding to two +1 defects at the poles. Finally, bands fold onto themselves, followed by the system moving into a turbulent state marked by active proliferation of pairs of topological defects. We highlight the role of nematic persistence length and time for pattern formation in these confined systems with finite curvature.

10 pages, 9 figures, includes SI

References in corpus (16)

• Novel type of phase transition in a system of self-driven particles
• Motility-Induced Phase Separation
• Spontaneous motion in hierarchically assembled active matter
• Topology and Dynamics of Active Nematic Vesicles
• Phase transition in the collective migration of tissue cells: experiment and model
• Topological defect launches 3D mound in the active nematic sheet of neural progenitors
• Minimal model for active nematics: quasi-long-range order and giant fluctuations
• Topological Defects in Spherical Nematics
• Topological Sound and Flocking on Curved Surfaces
• Correlation lengths in hydrodynamic models of active nematics
• Dynamically Generated Patterns in Dense Suspensions of Active Filaments
• Active swarms on a sphere
• Probing the shear viscosity of an active nematic
• Aging and rejuvenation of active matter under topological constraints
• Vortex formation and dynamics of defects in shells of active nematics
• Curvature-controlled defect dynamics in active systems

Cited by in corpus (27)

• Topology and morphology of self-deforming active shells
• Self-Aligning Polar Active Matter
• Three-Dimensional Active Defect Loops
• Active crystals on a sphere
• Vesicle shape transformations driven by confined active filaments
• Topology of three-dimensional active nematic turbulence confined to droplets
• Active motion on curved surfaces
• Newton-Cartan Submanifolds and Fluid Membranes
• Dynamics of active nematic defects on the surface of a sphere
• Optimal navigation of microswimmers in complex and noisy environments
• Optimal navigation strategies for microswimmers on curved manifolds
• Vortex Flows and Streamline Topology in Curved Biological Membranes
• Linearly forced fluid flow on a rotating sphere
• Alignment interactions drive structural transitions in biological tissues
• Tuneable defect-curvature coupling and topological transitions in active shells
• Multicomponent Flow on Curved Surfaces: A Vielbein Lattice Boltzmann Approach
• Effects of local curvature on epithelia tissue -- coordinated rotational movement and other spatiotemporal arrangements
• Effect of Confinement and Topology: 2-TIPS vs MIPS
• Rototaxis: localization of active motion under rotation
• Fractional and scaled Brownian motion on the sphere: The effects of long-time correlations on navigation strategies
• Active Filaments on Curved Surfaces: From Single Filaments to Dilute Suspensions
• Active smectics on a sphere
• Axisymmetric flows on the torus geometry
• A geometric framework for curvature-dependent collective behavior of polar active agents on curved surfaces
• Vielbein Lattice Boltzmann approach for fluid flows on spherical surfaces
• Paramagnetism in spherically confined charged active matter
• Individual particle persistence antagonizes global ordering in populations of nematically-aligning self-propelled particles