Emergent self-propulsion at low Reynolds number

TL;DR

This paper reports the experimental creation of inanimate micro-swimmer complexes that exhibit emergent self-propulsion at very low Reynolds numbers in colloidal systems, demonstrating collective motion without individual propulsion.

Contribution

It introduces a novel experimental realization of self-organized micro-swimmers that move collectively at low Reynolds numbers, a phenomenon not observed in individual constituents.

Findings

Self-propulsion observed for up to 25 minutes

Velocities of 1-3 μm/s achieved

No individual constituent shows self-propulsion

Abstract

We here demonstrate the experimental realization of inanimate micro-swimmer complexes showing emergent self-propulsion at low Reynolds number Re < 10^(-4) in quasi 2D colloidal systems. Guided by the substrate, self-organized propulsion occurs for up to 25min with typical velocities of 1-3 \mu m/s, while none of the involved constituents shows self-propulsion on its own.