Capillary surfers: wave-driven particles at a vibrating fluid interface

TL;DR

This paper introduces capillary surfers, wave-driven particles at a vibrating fluid interface, demonstrating tunable self-propulsion and interactions that lead to diverse collective behaviors, bridging dissipation and inertia regimes.

Contribution

It presents the first experimental investigation of capillary surfers, revealing their wave-mediated interactions and multistable modes, expanding understanding of active matter at fluid interfaces.

Findings

Surfers' speed can be tuned via particle, fluid, and vibration parameters.

Wave interactions enable multistability of interaction modes.

Potential for novel collective behaviors in active fluid systems.

Abstract

We present an experimental study of capillary surfers, a new fluid-mediated active system that bridges the gap between dissipation- and inertia-dominated regimes. Surfers are wave-driven particles that self-propel and interact on a fluid interface via an extended field of surface waves. A surfer's speed and interaction with its environment can be tuned broadly through the particle, fluid, and vibration parameters. The wave nature of interactions among surfers allows for multistability of interaction modes and promises a number of novel collective behaviors.