Large-scale dynamics in visual quorum sensing chiral suspensions

TL;DR

This paper demonstrates how simple visual quorum sensing rules in active particle suspensions induce programmable collective behaviors, including phase separation, hyper-uniformity, and large-scale circulation, even without steric interactions.

Contribution

It introduces a novel quorum sensing mechanism based on visual perception that controls collective dynamics in active matter, enabling programmable phase transitions and circulation.

Findings

Tuning visual cone triggers transitions from disorder to phase separation to hyper-uniformity.

Phase separation induces persistent large-scale circulation and edge currents.

Only 5% quorum-sensing particles induce collective circulation in active-passive mixtures.

Abstract

Motility induced phase separation is an efficient aggregation mechanism of active matter, yet biological systems exhibit richer organization through communication among constituents. We investigate suspensions of active particles that change chirality when neighbor density within their visual cone exceeds a threshold, a communication based non-reciprocal interaction akin to quorum sensing. Tuning the visual cone triggers programmable transitions: from disorder to phase separation to hyper-uniformity. Notably, phase separation triggers large-scale circulation, with robust edge currents persistently flowing around dense clusters, while particle distributions inside become effectively hyper-uniform. These are genuine non-reciprocal effects which occur even in the absence of steric interactions. Remarkably, in active-passive mixtures, only 5% quorum-sensing chiral particles suffice to induce collective circulation. Thus, simple perception-based rules can generate life-like order, offering design principles for programmable active materials and micro-robotic swarms.