Screened hydrodynamic interaction in a narrow channel

Cui, Bianxiao; Diamant, Haim; Lin, Binhua

Screened hydrodynamic interaction in a narrow channel

Authors

Cui, Bianxiao

Diamant, Haim

Lin, Binhua

Description

We study experimentally and theoretically the hydrodynamic coupling between Brownian colloidal particles diffusing along a linear channel. The quasi-one-dimensional confinement, unlike other constrained geometries, leads to a sharply screened interaction. Consequently, particles move in concert only when their mutual distance is smaller than the channel width, and two-body interactions remain dominant up to high particle densities. The coupling in a cylindrical channel is predicted to reverse sign at a certain distance, yet this unusual effect is too small to be currently detectable.
4 pages, 4 figures