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Emergent vortices in populations of colloidal rollers.

ABSTRACT: Coherent vortical motion has been reported in a wide variety of populations including living organisms (bacteria, fishes, human crowds) and synthetic active matter (shaken grains, mixtures of biopolymers), yet a unified description of the formation and structure of this pattern remains lacking. Here we report the self-organization of motile colloids into a macroscopic steadily rotating vortex. Combining physical experiments and numerical simulations, we elucidate this collective behaviour. We demonstrate that the emergent-vortex structure lives on the verge of a phase separation, and single out the very constituents responsible for this state of polar active matter. Building on this observation, we establish a continuum theory and lay out a strong foundation for the description of vortical collective motion in a broad class of motile populations constrained by geometrical boundaries.

SUBMITTER: Bricard A

PROVIDER: S-EPMC4557359 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature

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Emergent vortices in populations of colloidal rollers.

Bricard Antoine A Caussin Jean-Baptiste JB Das Debasish D Savoie Charles C Chikkadi Vijayakumar V Shitara Kyohei K Chepizhko Oleksandr O Peruani Fernando F Saintillan David D Bartolo Denis D

Nature communications 20150619

Coherent vortical motion has been reported in a wide variety of populations including living organisms (bacteria, fishes, human crowds) and synthetic active matter (shaken grains, mixtures of biopolymers), yet a unified description of the formation and structure of this pattern remains lacking. Here we report the self-organization of motile colloids into a macroscopic steadily rotating vortex. Combining physical experiments and numerical simulations, we elucidate this collective behaviour. We de ...[more]

PMID: 26088835

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