Artificial life of an active droplets system: a quantitative lifecycle analysis

TL;DR

This paper investigates the lifecycle and collective behavior of active oil droplets, providing quantitative analysis and tools that advance the understanding and design of synthetic life-like active matter systems.

Contribution

It introduces a comprehensive quantitative lifecycle analysis of active droplets and develops tracking tools to study their emergent behaviors, aiding future synthetic active matter research.

Findings

Identification of a life-to-death cycle in droplet dynamics

Demonstration of complex interplay between individual and collective behavior

Development of a tracking pipeline for long-duration droplet trajectories

Abstract

The study of synthetic active matter systems holds the promise for designing smart materials and devices with emergent characteristics akin to those of living organisms, eventually opening the doors to the realization of artificial life. Such an investigation, however, is challenged by the difficulty inherent in identifying the relationship between the features of the elementary constituents and the emergent properties of the whole; to this end, a key step consists in the accurate quantification of the system's observed behavior. Here, we report the study of 50 self-propelled oil droplets floating on the surface of an aqueous solution. 25 droplets are stained with a red dye, and the other 25 are stained blue: the colorants affect the droplets' interfacial tension properties differently, consequently influencing their collective dynamics. Droplet trajectories extending for up to 5 hours are extracted from video recordings with a tracking pipeline developed ad hoc. The structural and dynamical analysis of the system reveals a ``life-to-death'' cycle unfolding in qualitatively distinct stages, showcasing a complex interplay between individual droplet mobility and collective organization. The tools developed and the results obtained in our work pave the way to the in silico modelling as well as the experimental design of synthetic active matter systems displaying life-like and programmable behavior.