Emergent Structures in an Active Polar Fluid : dynamics of shape, scattering and merger

Abstract

Spatially localised defect structures emerge spontaneously in a hydrodynamic description of an active polar fluid comprising polar 'actin' filaments and 'myosin' motor proteins that (un)bind to filaments and exert active contractile stresses. These emergent defect structures are characterized by distinct textures and can be either static or mobile - we derive effective equations of motion for these 'extended particles' and analyse their shape, kinetics, interactions and scattering. Depending on the impact parameter and propulsion speed, these active defects undergo elastic scattering or merger. Our results are relevant for the dynamics of actomyosin-dense structures at the cell cortex, reconstituted actomyosin complexes and 2D active colloidal gels.

To appear in Phys. Rev. Lett. Movies available on request

References in corpus (12)

• Spontaneous motion in hierarchically assembled active matter
• Topology and Dynamics of Active Nematic Vesicles
• Orientational order of motile defects in active nematics
• Defect dynamics in active nematics
• Dynamic clustering and chemotactic collapse of self-phoretic active particles
• Stabilization of active matter by flow-vortex lattices and defect ordering
• Clustering and pattern formation in chemorepulsive active colloids
• Excitable Patterns in Active Nematics
• Hydrodynamics of isotropic and liquid crystalline active polymer solutions
• Phase segregation of passive advective particles in an active medium
• Shear flow induced isotropic to nematic transition in a suspension of active filaments
• Collision between chemically-driven self-propelled drops

Cited by in corpus (13)

• Pairing, waltzing and scattering of chemotactic active colloids
• Active emulsions in living cell membranes driven by contractile stresses and transbilayer coupling
• Metastability of Constant-Density Flocks
• Coarsening in the two-dimensional incompressible Toner-Tu equation: Signatures of turbulence
• Binding self-propelled topological defects in active turbulence
• Self-organization and shape change by active polarization in nematic droplets
• Active Segregation Dynamics in the Living Cell
• Nucleation and shape dynamics of model nematic tactoids around adhesive colloids
• Active waves from non-reciprocity and cytoplasmic exchange
• Supramolecular assemblies in active motor-filament systems: micelles, bilayers, and foams
• Coarsening of topological defects in 2D polar active matter
• Thermotaxis of Janus Particles
• Spatiotemporal model of cellular mechanotransduction via Rho and YAP