Chirality separation of mixed chiral microswimmers in a periodic channel

TL;DR

This study investigates how mixed chiral microswimmers behave and can be separated in a patterned channel, revealing how flow and parameters influence their transport and enabling a new space separation method.

Contribution

The paper introduces a numerical analysis of chiral microswimmer dynamics in a channel with obstacles, demonstrating parameter tuning for effective chirality-based separation.

Findings

Transport velocity decreases with rotational diffusion.

Angular velocity can reverse transport direction.

Chirality-based separation is achievable with parameter tuning.

Abstract

Dynamics and separation of mixed chiral microswimmers are numerically investigated in a channel with regular arrays of rigid half-circle obstacles. For zero shear flow, transport behaviors are the same for different chiral particles: the average velocity decreases with increase of the rotational diffusion coefficient, the direction of the transport can be reversed by tuning the angular velocity, and there exists an optimal value of the packing fraction at which the average velocity takes its maximal value. However, when the shear flow is considered, different chiral particles show different behaviors. By suitably tailoring parameters, particles with different chiralities can move in different directions and be separated. In addition, we also proposed a space separation method by introducing a constant load, where counterclockwise and clockwise particles stay in different regions of the channel.