Trapping and sorting active particles: motility-induced condensation & smectic defects

Abstract

We present an experimental realization of the collective trapping phase transition [Kaiser et al., PRL 108, 268307 (2012)], using motile polar granular rods in the presence of a V-shaped obstacle. We offer a theory of this transition based on the interplay of motility-induced condensation and liquid-crystalline ordering and show that trapping occurs when persistent influx overcomes the collective expulsion of smectic defect structures. In agreement with the theory, our experiments find that a trap fills to the brim when the trap angle $\theta$ is below a threshold ${\theta }_c$, while all particles escape for $\theta >{\theta }_c$. Our simulations support a further prediction, that ${\theta }_c$ goes down with increasing rotational noise. We exploit the sensitivity of trapping to the persistence of directed motion to sort particles based on the statistical properties of their activity

arXiv comment6 pages, 5 figures, for supplementary mpg files, see "https://www.dropbox.com/sh/3cmswfoysdn0sb6/AACpEp-G3768B6Y62nDFj_Hea?dl=0". This paper supersedes our earlier version arXiv:1603.08535 and contains substantial new results including revised theoretical treatment

References in corpus (17)

• The Mechanics and Statistics of Active Matter
• Motility-Induced Phase Separation
• Spontaneous motion in hierarchically assembled active matter
• Physics of Microswimmers - Single Particle Motion and Collective Behavior
• Athermal Phase Separation of Self-Propelled Particles with no Alignment
• Statistical Mechanics of Interacting Run-and-Tumble Bacteria
• Long-lived Giant Number Fluctuations in a Swarming Granular Nematic
• Collective Motion of Vibrated Polar Disks
• Swarming and swirling in self-propelled polar granular rods
• Flocking at a distance in active granular matter
• How to capture active particles
• Sorting of Chiral Microswimmers
• Upstream swimming in microbiological flows
• Symmetry properties of the large-deviation function of the velocity of a self-propelled polar particle
• Motility-sorting of self-propelled particles in micro-channels
• Dynamics of Gas-Fluidized Granular Rods
• Anisotropic Isometric Fluctuation Relations in experiment and theory on a self-propelled rod

Cited by in corpus (28)

• Statistical Mechanics of Active Ornstein Uhlenbeck Particles
• Design of nematic liquid crystals to control microscale dynamics
• Active nonreciprocal attraction between motile particles in an elastic medium
• Role of rotational inertia for collective phenomena in active matter
• Activity-controlled clogging and unclogging of micro-channels
• Time-dependent properties of interacting active matter: dynamical behavior of one-dimensional systems of self-propelled particles
• Collective mechano-response dynamically tunes cell-size distributions in growing bacterial colonies
• Narrow-escape time and sorting of active particles in circular domains
• Morphological transitions of active Brownian particle aggregates on porous walls
• Programming tunable active dynamics in a self-propelled robot
• The escape problem for active particles confined to a disc
• Vorticity Determines the Force on Bodies Immersed in Active Fluids
• Aggregate morphology of active Brownian particles on porous, circular walls
• Motile dissenters disrupt the flocking of active granular matter
• Motor crosslinking augments elasticity in active nematics
• Controlling the transport of active matter in disorderd lattices of asymmetrical obstacles
• Defect dynamics in active smectics induced by confining geometry and topology
• Catapulting of topological defects through elasticity bands in active nematics
• Collective dynamics of active dumbbells near a circular obstacle
• Bulk condensation by an active interface
• Phases and correlations in active nematic granular systems
• Emergent short-range repulsion for attractively coupled active particles
• Sorting of binary active-passive mixtures in designed microchannels
• Spontaneous Emergence of Run-and-Tumble-Like Dynamics in a Robotic Analog of \textit{Chlamydomonas}: Experiment and Theory
• Dynamical Boundary Following and Corner Trapping of Undulating Worms
• Topology of orientational defects in confined smectic liquid crystals
• Confinement-induced collective motion in suspensions of run-and-tumble particles
• From Attraction to Repulsion: Emergent Interactions in Harmonically Coupled Active Binary System