Periodic and Quasiperiodic Motion of an Elongated Microswimmer in Poiseuille Flow

TL;DR

This paper investigates the complex periodic and quasiperiodic motions of elongated microswimmers in various Poiseuille flow geometries, revealing how shape and channel symmetry influence their dynamic behaviors.

Contribution

It provides a detailed analysis of how swimmer shape and channel geometry affect periodic and quasiperiodic motions in microswimmer dynamics.

Findings

Swimmers exhibit swinging or tumbling motions depending on geometry.

Frequency of motions depends on the swimmer's aspect ratio.

Quasiperiodic motion occurs in channels with reduced symmetry.

Abstract

We study the dynamics of a prolate spheroidal microswimmer in Poiseuille flow for different flow geometries. When moving between two parallel plates or in a cylindrical microchannel, the swimmer performs either periodic swinging or periodic tumbling motion. Although the trajectories of spherical and elongated swimmers are qualitatively similar, the swinging and tumbling frequency strongly depends on the aspect ratio of the swimmer. In channels with reduced symmetry the swimmers perform quasiperiodic motion which we demonstrate explicitely for swimming in a channel with elliptical cross section.