title: Swimming in circles: motion of bacteria near solid boundaries.
abstract: Near a solid boundary, Escherichia coli swims in clockwise circular motion. We provide a hydrodynamic model for this behavior. We show that circular trajectories are natural consequences of force-free and torque-free swimming and the hydrodynamic interactions with the boundary, which also leads to a hydrodynamic trapping of the cells close to the surface. We compare the results of the model with experimental data and obtain reasonable agreement. In particular, the radius of curvature of the trajectory is observed to increase with the length of the bacterium body.
authors.affiliation: Division of Engineering and Applied Sciences, and Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02139, USA. lauga@mit.edu
authors.forename: Eric
authors.initials: E
authors.lastname: Lauga
authors.forename: Willow R
authors.initials: WR
authors.lastname: DiLuzio
authors.forename: George M
authors.initials: GM
authors.lastname: Whitesides
authors.forename: Howard A
authors.initials: HA
authors.lastname: Stone
mesh_terms: D000465:Algorithms; D001419:Bacteria / Q000378:metabolism; D001422:Bacterial Adhesion; D018407:Bacterial Physiological Phenomena; D001703:Biophysics / Q000379:methods*; D002465:Cell Movement; D002633:Chemotaxis; D003198:Computer Simulation; D004926:Escherichia coli / Q000378:metabolism; D005407:Flagella / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D008858:Microscopy, Phase-Contrast; D018715:Microscopy, Video; D008954:Models, Biological; D015233:Models, Statistical; D008962:Models, Theoretical; D009038:Motion; D009068:Movement