Bacterial accumulation mediated by ow compression-expansion

G.L. MIÑO; E. ALTSHULER; A. LINDNER; R. STOCKER; C.A. CONDAT; A.J. BANCHIO; V.I. MARCONI; E. CLEMENT

San Francisco

Congreso; DFD14 Meeting of The American Physical Society; 2014

APS

DFD14-2014-002282 Abstract Submitted for the DFD14 Meeting of The American Physical Society Sorting Category: 4.5 (ET) Bacterial accumulation mediated by flow compressionexpansion GAST´ON L. MI?NO, MIT, ERNESTO ALTSHULER, Physics Faculty-IMRE, University of Havana, Cuba, ANKE LINDNER, PMMH-ESPCI, France, ROMAN STOCKER, MIT, CARLOS A. CONDAT, ADOLFO J. BANCHIO, VERONICA I. MARCONI, IFEGCONICET and FaMAF-Universidad Nacional de Cordoba, Argentina, ERIC CL´EMENT, PMMH-ESPCI, France?Swimming bacteria can be concentrated using a suitable microfluidic device. The combination of flow rate and surface shape can have significant impact on the microorganisms behavior. In those processes rheotaxis, accumulation caused by ratches and even attachment to surfaces leading biofilm formation can be observed. Under these conditions, the transport of the active suspension is deeply modified, and differs significantly from passive suspensions. In this work, we present experimental evidence of Escherichia coli suspension flowing in a straight channel with a funnel-like constriction in the middle. This constriction is characterized by the aperture (wf ) and its angle (f ). We explore how the modification of wf and f affects the accumulation of bacteria in the channel. Concentrations of bacteria passing the constriction were observed for all the cases. However, the range of the flow rate that produced such accumulation varied with the geometry. In order to obtain a better understanding of this phenomenon, experiments are compared with a simple phenomenological model. Prefer Oral Session X Prefer Poster Session Gast´on L. Mi?no glmino@mit.edu MIT Date submitted: 01 Aug 2014 Electronic form version 1.4