Emergent comet-like swarming of optically driven thermally active colloids

TL;DR

This paper introduces a system of optically driven, thermally active colloids that self-organize into a dynamic, comet-like swarm exhibiting complex behaviors such as circulation, shape fluctuations, and ejection of hot particles, controlled by light intensity.

Contribution

It demonstrates a novel self-organizing behavior in thermally active colloids driven by optical heating, with detailed characterization of swarm dynamics and responses.

Findings

Formation of a self-organized comet-like swarm

Swarm exhibits circulation, shape, and density fluctuations

Hot colloid ejection from swarm tip

Abstract

We propose a simple system of optically driven colloids that convert light into heat and move in response to self- and collectively- generated thermal gradients. We show that the system exhibits self-organization into a moving comet-like swarm and characterize the structure and response of the swarm to a light intensity dependent external tuning parameter. We observe many interesting features in this nonequilibrium system including circulation and evaporation, intensity-dependent shape, density and temperature fluctuations, and ejection of hot colloids from the swarm tip.