title: Hydrodynamic coupling of two brownian spheres to a planar surface.
abstract: We describe direct imaging measurements of the collective and relative diffusion of two colloidal spheres near a flat plate. The bounding surface modifies the spheres' dynamics, even at separations of tens of radii. This behavior is captured by a stokeslet analysis of fluid flow driven by the spheres' and wall's no-slip boundary conditions. In particular, this analysis reveals surprising asymmetry in the normal modes for pair diffusion near a flat surface.
authors.affiliation: Department of Physics, James Franck Institute, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: E R
authors.initials: ER
authors.lastname: Dufresne
authors.forename: T M
authors.initials: TM
authors.lastname: Squires
authors.forename: M P
authors.initials: MP
authors.lastname: Brenner
authors.forename: D G
authors.initials: DG
authors.lastname: Grier
mesh_terms: D003102:Colloids / Q000737:chemistry*; D004058:Diffusion; D008956:Models, Chemical; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties
chemical_list: D003102:Colloids; D012822:Silicon Dioxide