Active control of transport through nanopores

TL;DR

This study investigates how active forces influence particle transport through nanopores, demonstrating enhanced efficiency and complex dynamics, with implications for controlling transport in nanofluidic systems.

Contribution

It introduces a mean-field and molecular dynamics analysis showing active force effects on nanopore transport, including an expression for effective diffusion and surface roughness impact.

Findings

Active force increases transport efficiency, with $D_{eff} = D_t (1 + Pe^2/6)$.

Particles inside the channel exhibit subdiffusion then normal diffusion over time.

Increased surface roughness traps more particles, reducing transport efficiency.

Abstract

Passive particle transport through narrow channels is well studied, while for active particle systems, it is not well understood. Here, we demonstrate the active control of the transport through a nanopore via mean-field analysis and molecular dynamics simulations. We prove that the active force enhances the transport efficiency with an effective diffusion coefficient $D_{eff} = D_t (1 + Pe^2/6)$, where $D_t$ is the translational diffusion coefficient, and $Pe$ is the P\'{e}clet number that determines the strength of the active force. For the number of particles inside the channel, it experiences subdiffusion at short times and then turns to normal at longer times. Finally, we extend our research for several sinusoidal shapes of the channel surface. More particles are trapped in the channel if the roughness of the channel surface is increased, resulting in fewer particles are transported from one side of the channel to the other.