A note on higher order perturbative corrections to squirming speed in weakly viscoelastic fluids

TL;DR

This paper investigates how higher order viscoelastic effects influence the swimming speed of microswimmers modeled as squirmers in complex fluids, addressing recent discussions on parameter choices and nonlinear effects.

Contribution

It provides an analysis of higher order perturbative corrections to squirmer speed in viscoelastic fluids, expanding understanding beyond linear approximations.

Findings

Higher order effects significantly alter squirming speed.

Parameter choices critically impact model predictions.

Nonlinear viscoelastic effects are essential for accurate modeling.

Abstract

Many microorganisms swim in fluids with complex rheological properties. Although much is now understood about motion of these swimmers in Newtonian fluids, the understanding is still developing in non-Newtonian fluids --- this understanding is crucial for various biomimetic and biomedical applications. Here we study a common model for microswimmers, the squirmer model, in two common viscoelastic fluid models, the Giesekus fluid model and fluids of differential type (grade three), at zero Reynolds number. Through this article we address a recent commentary that discussed suitable values of parameters in these model and pointed at higher order viscoelastic effects on the squirming motion.