Inertial effects on rectification and diffusion of active Brownian particles in an asymmetric channel

Abstract

Micro- and nano-swimmers moving in a fluid solvent confined by structures that produce entropic barriers are often described by overdamped active Brownian particle dynamics, where viscous effects are large and inertia plays no role. However, inertial effects should be considered for confined swimmers moving in media where viscous effects are no longer dominant. Here, we study how inertia affects the rectification and diffusion of self-propelled particles in a two-dimensional asymmetric channel. We show that most of the particles accumulate at the channel walls as the masses of the particles increase. Furthermore, the average particle velocity has a maximum as a function of the mass, indicating that particles with an optimal mass $M_{\mathrm{op}}^{\ast }$ can be sorted from a mixture with particles of other masses. In particular, we find that the effective diffusion coefficient exhibits an enhanced diffusion peak as a function of the mass, which is a signature of the accumulation of most of the particles at the channel walls. The dependence of $M_{\mathrm{op}}^{\ast }$ on the rotational diffusion rate, self-propulsion force, aspect ratio of the channel, and active torque is also determined. The results of this study could stimulate the development of strategies for controlling the diffusion of self-propelled particles in entropic ratchet systems.

arXiv comment7 pages, 7 figures

References in corpus (37)

• Active Particles in Complex and Crowded Environments
• The hydrodynamics of swimming microorganisms
• The Mechanics and Statistics of Active Matter
• Physics of Microswimmers - Single Particle Motion and Collective Behavior
• Athermal Phase Separation of Self-Propelled Particles with no Alignment
• Active Brownian Particles. From Individual to Collective Stochastic Dynamics
• The 2019 Motile Active Matter Roadmap
• Diffusive transport without detailed balance in motile bacteria: Does microbiology need statistical physics?
• Kinetic Equations for Diffusion in the Presence of Entropic Barriers
• Emergent behavior in active colloids
• Self-propelled Janus particles in a ratchet: Numerical simulations
• Inertial effects of self-propelled particles: from active Brownian to active Langevin motion
• 'Fuelled' motion: phoretic motility and collective behaviour of active colloids
• Inertial delay of self-propelled particles
• Minimal model of active colloids highlights the role of mechanical interactions in controlling the emergent behavior of active matter
• A Classical Density-Functional Theory for Describing Water Interfaces
• Motility-induced temperature difference in coexisting phases
• Odd Diffusivity of Chiral Random Motion
• Active Brownian motion in a narrow channel
• Tunable mass separation via negative mobility
• Time-dependent inertia of self-propelled particles: the Langevin rocket
• Model microswimmers in channels with varying cross section
• Role of rotational inertia for collective phenomena in active matter
• Fluctuating chemohydrodynamics and the stochastic motion of self-diffusiophoretic particles
• Entropic Ratchet transport of interacting active Brownian particles
• Activity-controlled clogging and unclogging of micro-channels
• Transport of active particles in an open-wedge channel
• Thermodynamics and statistical mechanics of chemically-powered synthetic nanomotors
• Active matter, microreversibility, and thermodynamics
• Diffusion of interacting particles in a channel with reflection boundary conditions
• Diffusion of chiral active particles in a Poiseuille flow
• Molecular theory of Langevin dynamics for active self-diffusiophoretic colloids
• Rectification of Twitching bacteria through narrow channels: A numerical simulations study
• Confined diffusion in a random Lorentz gas environment
• Interacting Brownian particles exhibiting enhanced rectification in an asymmetric channel
• Active aerosols
• Mass separation in an asymmetric channel

Cited by in corpus (3)

• Engineering Ratchet-Based Particle Separation via Shortcuts to Isothermality
• Diffusion of gravitactic chiral active Brownian particles in an asymmetric channel
• Mass-based separation of active Brownian particles in an asymmetric channel