Active particle diffusion in convection roll arrays.

Area of Science:

• Physics
• Nanotechnology
• Soft Matter Physics

Background:

• Active matter transport is crucial for nanotechnology but often hindered by undesired advection.
• Controlling nanoscale particle movement requires understanding interactions between self-propulsion and fluid dynamics.

Purpose of the Study:

• To numerically investigate the Brownian motion of active Janus particles in a convection roll array.
• To characterize how advection and self-propulsion parameters influence particle diffusion and spatial distribution at high Péclet numbers.

Main Methods:

• Numerical simulation of active Janus particle Brownian motion.
• Analysis of particle transport in a linear array of planar counter-rotating convection rolls.
• Investigation at high Péclet numbers, examining effects of self-propulsion speed.

Main Results:

• Active particles show advection-enhanced diffusion up to a critical self-propulsion speed.
• Faster particles exhibit distinct diffusion regimes governed by edge advection.
• Spatial distributions of active particles are inhomogeneous, unlike passive particles.

Conclusions:

• Particle transport in confined active matter systems can be governed by tuning advection and self-propulsion.
• The interplay of noise, self-propulsion, and confinement creates unique diffusion behaviors.
• These findings are relevant for controlling active matter in nano-technological applications.