Diffusion-based height analysis reveals robust microswimmer-wall separation
Soft Condensed Matter
2020-12-30 v2
Abstract
Microswimmers typically move near walls, which can strongly influence their motion. However, direct experimental measurements of swimmer-wall separation remain elusive to date. Here, we determine this separation for model catalytic microswimmers from the height dependence of the passive component of their mean-squared displacement. We find that swimmers exhibit "ypsotaxis", a tendency to assume a fixed height above the wall for a range of salt concentrations, swimmer surface charges, and swimmer sizes. Our findings indicate that ypsotaxis is activity-induced, posing restrictions on future modeling of their still debated propulsion mechanism.
Cite
@article{arxiv.2006.06384,
title = {Diffusion-based height analysis reveals robust microswimmer-wall separation},
author = {Stefania Ketzetzi and Joost de Graaf and Daniela J. Kraft},
journal= {arXiv preprint arXiv:2006.06384},
year = {2020}
}