title: Clustering and Pattern Formation in Chemorepulsive Active Colloids.
abstract: We demonstrate that migration away from self-produced chemicals (chemorepulsion) generates a generic route to clustering and pattern formation among self-propelled colloids. The clustering instability can be caused either by anisotropic chemical production, or by a delayed orientational response to changes of the chemical environment. In each case, chemorepulsion creates clusters of a self-limiting area which grows linearly with self-propulsion speed. This agrees with recent observations of dynamic clusters in Janus colloids (albeit not yet known to be chemorepulsive). More generally, our results could inform design principles for the self-assembly of chemorepulsive synthetic swimmers and/or bacteria into nonequilibrium patterns.
authors.affiliation: SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom.
authors.forename: Benno
authors.initials: B
authors.lastname: Liebchen
authors.affiliation: SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom.
authors.forename: Davide
authors.initials: D
authors.lastname: Marenduzzo
authors.affiliation: Departament de Física Fonamental, Universitat de Barcelona-Carrer Martí i Franquès 1, 08028-Barcelona, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Pagonabarraga
authors.affiliation: DAMTP, Centre for Mathematical Sciences, University of Cambridge, Cambridge CB3 0WA, United Kingdom.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Cates
mesh_terms: D001419:Bacteria / Q000166:cytology; D018407:Bacterial Physiological Phenomena; D002630:Chemotactic Factors / Q000737:chemistry; D003102:Colloids / Q000737:chemistry*; D008954:Models, Biological; D013550:Swimming
chemical_list: D002630:Chemotactic Factors; D003102:Colloids