Confined active particles: wall accumulation and correspondence between active and fluid systems

Abstract

Active Brownian particles (ABPs) are a generic model for synthetic active matter systems, such as active colloids, characterized by their ability to self-propel while also exhibiting Brownian motion. Under confinement, ABPs display propulsion-induced wall accumulation, a behavior that can be harnessed for microfluidic and lab-on-a-chip applications. We investigate ABPs confined in slit pores using overdamped Langevin dynamics and study their wall accumulation as a function of particle activity and slit width, at both gas and liquid densities. Furthermore, we examine the correspondence between confined ABPs and their equilibrium counterparts, confined fluid particles capable of completely wetting the slit walls.