Oscillation patterns in active emulsion networks

TL;DR

This paper investigates water-in-oil emulsion droplets with chemical oscillations that can self-propel and synchronize, revealing how network topology influences their collective dynamics and motion in active matter systems.

Contribution

It introduces a new active matter system of chemically oscillating droplets capable of synchronization and explores how network structure affects their collective behavior.

Findings

Droplets exhibit synchronized chemical oscillations depending on network topology.

Chemical oscillations can be coupled via exchange of reaction intermediates.

Droplet motion can synchronize with internal chemical oscillations.

Abstract

We study water-in-oil emulsion droplets, running the Belousov-Zhabotinsky reaction, that form a new type of active matter unit. These droplets, stabilised by surfactants dispersed in the oil medium, are capable of internal chemical oscillations and also self-propulsion due to dynamic interfacial instabilities that result from the chemical reactions. The chemical oscillations can couple via the exchange of activator and inhibitor type of reaction intermediates across the droplets under precise conditions of surfactant bilayer formation between the droplets. Here we present the synchronization behaviour of networks of such chemical oscillators and show that the resulting dynamics depend on the network topology. Further, we demonstrate that the motion of droplets can be synchronized with the chemical oscillations inside the droplets, leading to exciting possibilities in future studies of active matter.