Collective dynamics of densely confined active polar disks with self- and mutual alignment

Abstract

We study the emerging collective states in a simple mechanical model of a dense group of self-propelled polar disks with off-centered rotation, confined within a circular arena. Each disk presents self-alignment towards the sum of contact forces acting on it, resulting from disk-substrate interactions, while also displaying mutual alignment with neighbors due to having its center of rotation located a distance R behind its centroid so that central contact forces can also introduce torques. The effect of both alignment mechanisms produces a variety of collective states that combine high-frequency localized circular oscillations with low-frequency milling around the center of the arena, in fluid or solid regimes. We consider cases with small/large R values, isotropic/anisotropic disk-substrate damping, smooth/rough arena boundaries, different densities, and multiple systems sizes, showing that the emergent collective states that we identify are robust, generic, and potentially observable in real-world natural or artificial systems.

arXiv comment13 pages, 9 figures

References in corpus (19)

• Novel type of phase transition in a system of self-driven particles
• Collective motion
• Interaction Ruling Animal Collective Behaviour Depends on Topological rather than Metric Distance: Evidence from a Field Study
• The Mechanics and Statistics of Active Matter
• Active Brownian Particles. From Individual to Collective Stochastic Dynamics
• Statistical mechanics for natural flocks of birds
• Collective Motion of Vibrated Polar Disks
• Phase transition in the collective migration of tissue cells: experiment and model
• Non-equilibrium clustering of self-propelled rods
• Active Jamming: Self-propelled soft particles at high density
• Collective motion and nonequilibrium cluster formation in colonies of gliding bacteria
• Collective Motion due to escape and pursuit response
• Selective and Collective Actuation in Active Solids
• Geometry-driven collective ordering of bacterial vortices
• Morphological computation and decentralized learning in a swarm of sterically interacting robots
• Self-Aligning Polar Active Matter
• Autonomous waves and global motion modes in living active solids
• Polar order, shear banding, and clustering in confined active matter
• A Mechanical Route for Cooperative Transport in Autonomous Robotic Swarms