title: Scattering and nonlinear bound states of hydrodynamically coupled particles in a narrow channel.
abstract: We model a pair of hydrodynamically interacting particles confined in a channel with thin rectangular cross section. We find that the particles have a finite region of attraction, which arises from the screening of dipolar hydrodynamic interactions by the side walls. Outside this region, the two particles break apart and scatter; inside, they oscillate together as an effectively free quasiparticle. We demonstrate that modulation of channel geometry provides a means to irreversibly manipulate bound pairs.
authors.affiliation: Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: William E
authors.initials: WE
authors.lastname: Uspal
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Doyle
mesh_terms: D057446:Hydrodynamics; D008956:Models, Chemical; D017711:Nonlinear Dynamics; D014783:Viscosity