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dc.contributor.authorSpagnolie, Saverio E
dc.contributor.authorMoreno-Flores, Gregorio R
dc.contributor.authorBartolo, Denis
dc.contributor.authorLauga, Eric
dc.date.accessioned2015-07-07T14:05:09Z
dc.date.available2015-07-07T14:05:09Z
dc.date.issued2015-05-07
dc.identifier.citationSoft Matter, 2015,11, 3396-3411 DOI: 10.1039/C4SM02785J
dc.identifier.issn1744-683X
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/248847
dc.description.abstractMotivated by recent experiments, we consider the hydrodynamic capture of a microswimmer near a stationary spherical obstacle. Simulations of model equations show that a swimmer approaching a small spherical colloid is simply scattered. In contrast, when the colloid is larger than a critical size it acts as a passive trap: the swimmer is hydrodynamically captured along closed trajectories and endlessly orbits around the colloidal sphere. In order to gain physical insight into this hydrodynamic scattering problem, we address it analytically. We provide expressions for the critical trapping radius, the depth of the "basin of attraction," and the scattering angle, which show excellent agreement with our numerical findings. We also demonstrate and rationalize the strong impact of swimming-flow symmetries on the trapping efficiency. Finally, we give the swimmer an opportunity to escape the colloidal traps by considering the effects of Brownian, or active, diffusion. We show that in some cases the trapping time is governed by an Ornstein-Uhlenbeck process, which results in a trapping time distribution that is well-approximated as inverse-Gaussian. The predictions again compare very favorably with the numerical simulations. We envision applications of the theory to bioremediation, microorganism sorting techniques, and the study of bacterial populations in heterogeneous or porous environments.
dc.description.sponsorshipG.R. Moreno-Flores acknowledges funding by Fondecyt grant 1130280 and Inicitativa Cientifica Milenio NC130062; and E. Lauga acknowledges from the European Union through a Marie Curie CIG Grant.
dc.languageEnglish
dc.language.isoen
dc.publisherRoyal Society of Chemistry (RSC)
dc.titleGeometric capture and escape of a microswimmer colliding with an obstacle.
dc.typeArticle
dc.description.versionThis is the accepted manuscipt. The final version is available at http://pubs.rsc.org/en/Content/ArticleLanding/2015/SM/C4SM02785J#!divAbstract.
prism.endingPage3411
prism.publicationDate2015
prism.publicationNameSoft Matter
prism.startingPage3396
prism.volume11
dc.rioxxterms.funderEU
rioxxterms.versionofrecord10.1039/c4sm02785j
rioxxterms.licenseref.urihttp://www.rioxx.net/licenses/all-rights-reserved
rioxxterms.licenseref.startdate2015-03-09
dc.contributor.orcidLauga, Eric Lauga [0000-0002-8916-2545]
dc.identifier.eissn1744-6848
rioxxterms.typeJournal Article/Review
cam.issuedOnline2015
rioxxterms.freetoread.startdate2016-03-09


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