Milling and meandering: Flocking dynamics of stochastically interacting agents with a field of view

Spontaneous stable rotation of flocking flexible active matter

In this paper we present an n-node flexible active matter model to study the collective motion due to the flocking of individual achiral agents on a two-dimensional surface. By introducing a measure of the direction detectability of the agents to tune their body direction towards the food source, we find that a spontaneous stable cluster rotation emerges with increasing direction detectability. The spontaneous rotation is synchronized with the chirality produced by the alignment of their bodies under the impetus of the active force. A linear relationship between the normalized angular velocity and chirality is observed and the numerical simulation agrees well with the analytical derivation. The conclusions explain well the spontaneous stable rotation of clusters that exists in many flexible active matter systems, like worms or dogs, when they flock to the same single source.

Swirling Due to Misaligned Perception-Dependent Motility

A system of particles with motility variable in terms of a vision-type of perception is investigated by a combination of Langevin dynamics simulations in two-dimensional systems and an analytical approach based on conservation law principles. Persistent swirling with predetermined direction is here induced by differentiating the self-propulsion direction and the perception cone axis. Clusters can have a fluidlike center with a rotating outer layer or display a solidlike rotation driven by the outer layer activity. Discontinuous motility with misaligned perception might therefore serve as a powerful self-organization strategy in microrobots.