Dynamics of Deformable Active Particles under External Flow Field

TL;DR

This paper reviews the dynamics of active deformable particles in external flow fields, focusing on model equations and behaviors under shear and swirl flows, including scattering phenomena.

Contribution

It introduces a comprehensive set of model equations for active deformable particles affected by external flows, covering shear and swirl flow scenarios.

Findings

Dynamics under shear flow analyzed

Scattering behavior in swirl flow studied

Model equations for deformable active particles developed

Abstract

In most practical situations, active particles are affected by their environment, for example, by a chemical concentration gradient, light intensity, gravity, or confinement. In particular, the effect of an external flow field is important for particles swimming in a solvent fluid. For deformable active particles such as self-propelled liquid droplets and active vesicles, as well as microorganisms such as euglenas and neutrophils, a general description has been developed by focusing on shape deformation. In this review, we present our recent studies concerning the dynamics of a single active deformable particle under an external flow field. First, a set of model equations of active deformable particles including the effect of a general external flow is introduced. Then, the dynamics under two specific flow profiles is discussed: a linear shear flow, as the simplest example, and a swirl flow. In the latter case, the scattering dynamics of the active deformable particles by the swirl flow is also considered.