Escape kinetics of self-propelled particles from a circular cavity

Area of Science:

• Physics
• Soft Matter Physics
• Statistical Mechanics

Background:

• Active Brownian particles (ABPs) are fundamental models for self-propelled entities.
• Understanding particle dynamics in confined geometries is crucial for active matter transport.
• Exit time statistics reveal fundamental transport mechanisms.

Purpose of the Study:

• To numerically investigate the mean exit time of inertial ABPs from a circular cavity.
• To explore escape mechanisms influenced by particle properties and cavity geometry.
• To identify conditions for maximizing the particle exit rate.

Main Methods:

• Numerical simulations of inertial active Brownian particles.
• Analysis of escape mechanisms based on particle inertia, self-propulsion, and damping.
• Analytical interpretation of simulation results using qualitative arguments.

Main Results:

• Distinct escape mechanisms observed based on the ratio of thermal length, self-propulsion length, cavity size, and pore size.
• Overdamped regime: Rotational dynamics dominates exit.
• Underdamped regime: Wall collisions dictate escape kinetics.
• Maximal exit rate achieved at an optimal self-propulsion persistence length.
• Optimal persistence length is independent of exit window configuration.

Conclusions:

• The study elucidates the interplay between particle inertia, self-propulsion, and confinement on escape dynamics.
• An optimal self-propulsion persistence length maximizes transport efficiency.
• Findings provide insights into controlling active matter transport in structured environments.