Motility-induced phase separation and coarsening in active matter
arXiv:1502.02229 · doi:10.1016/j.crhy.2015.05.001
Abstract
Active systems, or active matter, are self-driven systems which live, or function, far from equilibrium - a paradigmatic example which we focus on here is provided by a suspension of self-motile particles. Active systems are far from equilibrium because their microscopic constituents constantly consume energy from the environment in order to do work, for instance to propel themselves. The nonequilibrium nature of active matter leads to a variety of non-trivial intriguing phenomena. An important one which has recently been the subject of intense interest among biological and soft matter physicists is that of the so-called "motility-induced phase separation", whereby self-propelled particles accumulate into clusters in the absence of any explicit attractive interactions between them. Here we review the physics of motility-induced phase separation, and discuss this phenomenon within the framework of the classic physics of phase separation and coarsening. We also discuss theories for bacterial colonies where coarsening may be arrested. Most of this work will focus on the case of run-and-tumble and active Brownian particles in the absence of solvent-mediated hydrodynamic interactions - we will briefly discuss at the end their role, which is not currently fully understood in this context.
Contribution to the special issue "Coarsening dynamics", Comptes Rendus de Physique, see https://sites.google.com/site/ppoliti/crp-special-issue
References in corpus (30)
- Novel type of phase transition in a system of self-driven particles
- The hydrodynamics of swimming microorganisms
- Self-motile colloidal particles: from directed propulsion to random walk
- Motility-Induced Phase Separation
- Physics of Microswimmers - Single Particle Motion and Collective Behavior
- Meso-scale turbulence in living fluids
- Statistical Mechanics of Interacting Run-and-Tumble Bacteria
- Hydrodynamic attraction of swimming microorganisms by surfaces
- Collective motion of self-propelled particles interacting without cohesion
- Designing phoretic micro- and nano-swimmers
- When are active Brownian particles and run-and-tumble particles equivalent? Consequences for motility-induced phase separation
- Diffusive transport without detailed balance in motile bacteria: Does microbiology need statistical physics?
- Non-equilibrium clustering of self-propelled rods
- Collective motion and nonequilibrium cluster formation in colonies of gliding bacteria
- Sedimentation, trapping, and rectification of dilute bacteria
- Pattern formation in self-propelled particles with density-dependent motility
- From Phase to Micro-Phase Separation in Flocking Models: The Essential Role of Non-Equilibrium Fluctuations
- Colloidal motility and pattern formation under rectified diffusiophoresis
- Swarm behavior of self-propelled rods and swimming flagella
- Shearing active gels close to the isotropic-nematic transition
- Self-Propelled Rods near Surfaces
- Fluctuations and Rheology in Active Bacterial Suspensions
- Clustering and heterogeneous dynamics in a kinetic Monte-Carlo model of self-propelled hard disks
- Orientational order in concentrated suspensions of spherical microswimmers
- Complex Spontaneous Flows and Concentration Banding in Active Polar Films
- Spontaneous aggregation and global polar ordering in squirmer suspensions
- Rheology of Active Filament Solutions
- Dynamics of a homogeneous active dumbbell system
- Activity-induced clustering in model dumbbell swimmers: The role of hydrodynamic interactions
- Stirring by swimmers in confined microenvironments