Trapping flocking particles with asymmetric obstacles

TL;DR

This paper demonstrates how asymmetric funnel obstacles can selectively trap flocking particles following the Vicsek model, revealing new ways to control collective motion in microfluidic environments.

Contribution

It introduces the concept of trapping flocking particles with asymmetric obstacles, showing collective trapping and dynamical behaviors not observed in run-and-tumbling particles.

Findings

Flocking particles can be completely trapped by funnel walls.

Distinct trapping regimes depend on particle interactions and obstacle design.

Potential applications in microfluidic device design for active matter control.

Abstract

Asymmetric obstacles can be exploited to direct the motion and induce sorting of run-and-tumbling particles. In this work, we show that flocking particles which follow the Vicsek model aligning rules experience a collective trapping in the presence of a wall of funnels made of chevrons, concentrating at the opposite side of a wall of funnels than run-and-tumbling particles. Flocking particles can be completely trapped or exhibit a dynamical trapping behaviour; these two regimes open the door to the design of a system with two perpendicular flows of active particles. This systematic study broaden our understanding about the emergence of collective motion of microorganisms in confined environments and direct the design of new microfluidics devices able to controlthese collective behaviours.