Surmounting Barriers: The Benefit of Hydrodynamic Interactions

TL;DR

This paper explores how hydrodynamic interactions influence the collective motion of colloidal particles, revealing a limit cycle and a novel caterpillar-like movement that helps particles overcome potential barriers.

Contribution

It introduces a combined experimental and theoretical study showing how hydrodynamic interactions induce new collective behaviors and barrier surmounting in colloidal particles.

Findings

Hydrodynamic interactions create a limit cycle in particle motion.

A novel caterpillar-like motional sequence is observed.

Hydrodynamic interactions facilitate overcoming potential barriers.

Abstract

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.