Narrow-escape time and sorting of active particles in circular domains

TL;DR

This paper investigates how motility parameters influence the escape time of active particles from circular domains, revealing a crossover behavior that can be exploited for particle sorting.

Contribution

It introduces a numerical analysis of the impact of motility on escape times, highlighting a crossover regime useful for sorting active particles based on their motility.

Findings

Escape time exhibits a crossover between two regimes.

The crossover depends on the ratio of persistence length to domain size.

Potential application in sorting particles by motility parameters.

Abstract

It is now well established that microswimmers can be sorted or segregated fabricating suitable microfluidic devices or using external fields. A natural question is how these techniques can be employed for dividing swimmers of different motility. In this paper, using numerical simulations in the dilute limit, we investigate how motility parameters (time of persistence and velocity) impacts the narrow-escape time of active particles from circular domains. We show that the escape time undergoes a crossover between two asymptotic regimes. The control parameters of the crossover is the ratio between persistence length of the active motion and the typical length scale of the circular domain. We explore the possibility of taking advantage of this finding for sorting active particles by motility parameters.