Hydroelastic scattering and trapping of microswimmers

TL;DR

This paper investigates how deformable boundaries affect the movement of microswimmers, revealing complex behaviors like scattering and trapping due to hydroelastic interactions.

Contribution

It introduces a perturbation theory for small deformations to analyze microswimmer dynamics near elastic boundaries, highlighting novel reorientation and trapping phenomena.

Findings

Pushers can reorient away or become trapped by boundaries.

Hydroelastic interactions lead to behaviors different from planar wall swimming.

Theoretical framework for small boundary deformations and swimmer interactions.

Abstract

Deformable boundaries are omnipresent in the habitats of swimming microorganisms, leading to intricate hydroelastic couplings. Employing a perturbation theory, valid for small deformations, we study the swimming dynamics of pushers and pullers near instantaneously deforming boundaries, endowed with a bending rigidity and surface tension. Our results reveal that pushers can both reorient away from the boundary, leading to overall hydroelastic scattering, or become trapped by the boundary, akin to the enhanced trapping found for pullers. These findings demonstrate that the complex hydroelastic interactions can generate behaviors that are in striking contrast to swimming near planar walls.