Surmounting barriers: The benefit of hydrodynamic interactionsC. Lutz1, M. Reichert2, H. Stark2, 3 and C. Bechinger1
1 2. Physikalisches Institut, Universität Stuttgart - Pfaffenwaldring 57 D-70550 Stuttgart, Germany
2 Universität Konstanz, Fachbereich Physik - D-78457 Konstanz, Germany
3 Max-Planck Institute for Dynamics and Self-Organization - Bunsenstr. 10 D-37073 Göttingen, Germany
received 10 January 2006; accepted in final form 9 March 2006
published online 7 April 2006
We experimentally and theoretically investigate the collective behavior of three colloidal particles that are driven by a constant force along a toroidal trap. Due to hydrodynamic interactions, a characteristic limit cycle is observed. When we additionally apply a periodic sawtooth potential, we find a novel caterpillar-like motional sequence that is dominated by hydrodynamic interactions and promotes the surmounting of potential barriers by the particles.
82.70.Dd - Colloids.
67.40.Hf - Hydrodynamics in specific geometries, flow in narrow channels.
83.80.Hj - Suspensions, dispersions, pastes, slurries, colloids.
© EDP Sciences 2006