Collective behavior of active molecules: dynamic clusters, holes and active fractalytes

TL;DR

This paper models active colloidal molecules, predicting dynamic clusters and a novel state called 'active fractalytes'—motile, fractal-structured crystallites with internal holes, opening new avenues for designing active materials.

Contribution

It introduces the concept of active fractalytes, a new state of active matter with fractal internal structures, expanding understanding of active colloidal systems.

Findings

Prediction of dynamic clusters in active molecules

Discovery of active fractalytes with fractal internal structure

Potential for designing active materials with tailored properties

Abstract

Recent experiments have led to active colloidal molecules which aggregate from non-motile building blocks and acquire self-propulsion through their non-reciprocal interactions. Here, we model the collective behavior of such active molecules and predict, besides dynamic clusters, the existence of a so-far unknown state of active matter made of 'active fractalytes' which are motile crystallites featuring internal holes, gaps and a fractal dimension. These structures could serve as a starting point for the creation of active materials with a low density and mechanical properties that can be designed through their fractal internal structure.