Emergence of lanes and turbulent-like motion in active spinner fluid

• Published in: Communications physics Vol. 4; no. 1; pp. 1 - 9
• Main Authors: Reeves, Cody J., Aranson, Igor S., Vlahovska, Petia M.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 10.05.2021; Nature Publishing Group; Springer Nature; Nature Portfolio
• Subjects: 639/301/923/916; 639/705/1041; active spinners; applied mathematics; Chirality; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; colloids; Computational fluid dynamics; Continuum modeling; Equations of motion; Fluid flow; Fluid inertia; Granulation; MATERIALS SCIENCE; Phase separation; Physics; Physics and Astronomy; Reynolds number; Rotating fluids; Rotation; self-assembly; Spinners
• ISSN: 2399-3650; 2399-3650
• DOI: 10.1038/s42005-021-00596-2

Assemblies of self-rotating particles are gaining interest as a novel realization of active matter with unique collective behaviors such as edge currents and non-trivial dynamic states. Here, we develop a continuum model for a system of fluid-embedded spinners by coarse-graining the equations of motion of the discrete particles. We apply the model to explore mixtures of clockwise and counterclockwise rotating spinners. We find that the dynamics is sensitive to fluid inertia; in the inertialess system, after transient turbulent-like motion the spinners segregate and form steady traffic lanes. At small but finite Reynolds number instead, the turbulent-like motion persists and the system exhibits a chirality breaking transition leading to a single rotation sense state. Our results shed light on the dynamic behavior of non-equilibrium materials exemplified by active spinners. Emergent collective behaviour has recently been addressed in systems of self-rotating particles, where motion, in particular, is an emergent phenomenon rather than a basic ingredient. Here, the authors derive a continuum model for mixtures of clockwise and counterclockwise Quincke spinners, demonstrating the emergence of same-spin phase separation, traffic lanes, sustained turbulent-like motion, and a chirality breaking transition depending on the fluid inertia of the system.