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Squirmer hydrodynamics near a periodic surface topography

The behaviour of microscopic swimmers has previously been explored near large-scale confining geometries and in the presence of very small-scale surface roughness. Here, we consider an intermediate case of how a simple microswimmer, the tangential spherical squirmer, behaves adjacent to singly and d...

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Autores principales: Ishimoto, Kenta, Gaffney, Eamonn A., Smith, David J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10133482/
https://www.ncbi.nlm.nih.gov/pubmed/37123410
http://dx.doi.org/10.3389/fcell.2023.1123446
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author Ishimoto, Kenta
Gaffney, Eamonn A.
Smith, David J.
author_facet Ishimoto, Kenta
Gaffney, Eamonn A.
Smith, David J.
author_sort Ishimoto, Kenta
collection PubMed
description The behaviour of microscopic swimmers has previously been explored near large-scale confining geometries and in the presence of very small-scale surface roughness. Here, we consider an intermediate case of how a simple microswimmer, the tangential spherical squirmer, behaves adjacent to singly and doubly periodic sinusoidal surface topographies that spatially oscillate with an amplitude that is an order of magnitude less than the swimmer size and wavelengths that are also within an order of magnitude of this scale. The nearest neighbour regularised Stokeslet method is used for numerical explorations after validating its accuracy for a spherical tangential squirmer that swims stably near a flat surface. The same squirmer is then introduced to different surface topographies. The key governing factor in the resulting swimming behaviour is the size of the squirmer relative to the surface topography wavelength. For instance, directional guidance is not observed when the squirmer is much larger, or much smaller, than the surface topography wavelength. In contrast, once the squirmer size is on the scale of the topography wavelength, limited guidance is possible, often with local capture in the topography troughs. However, complex dynamics can also emerge, especially when the initial configuration is not close to alignment along topography troughs or above topography crests. In contrast to sensitivity in alignment and topography wavelength, reductions in the amplitude of the surface topography or variations in the shape of the periodic surface topography do not have extensive impacts on the squirmer behaviour. Our findings more generally highlight that the numerical framework provides an essential basis to elucidate how swimmers may be guided by surface topography.
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spelling pubmed-101334822023-04-28 Squirmer hydrodynamics near a periodic surface topography Ishimoto, Kenta Gaffney, Eamonn A. Smith, David J. Front Cell Dev Biol Cell and Developmental Biology The behaviour of microscopic swimmers has previously been explored near large-scale confining geometries and in the presence of very small-scale surface roughness. Here, we consider an intermediate case of how a simple microswimmer, the tangential spherical squirmer, behaves adjacent to singly and doubly periodic sinusoidal surface topographies that spatially oscillate with an amplitude that is an order of magnitude less than the swimmer size and wavelengths that are also within an order of magnitude of this scale. The nearest neighbour regularised Stokeslet method is used for numerical explorations after validating its accuracy for a spherical tangential squirmer that swims stably near a flat surface. The same squirmer is then introduced to different surface topographies. The key governing factor in the resulting swimming behaviour is the size of the squirmer relative to the surface topography wavelength. For instance, directional guidance is not observed when the squirmer is much larger, or much smaller, than the surface topography wavelength. In contrast, once the squirmer size is on the scale of the topography wavelength, limited guidance is possible, often with local capture in the topography troughs. However, complex dynamics can also emerge, especially when the initial configuration is not close to alignment along topography troughs or above topography crests. In contrast to sensitivity in alignment and topography wavelength, reductions in the amplitude of the surface topography or variations in the shape of the periodic surface topography do not have extensive impacts on the squirmer behaviour. Our findings more generally highlight that the numerical framework provides an essential basis to elucidate how swimmers may be guided by surface topography. Frontiers Media S.A. 2023-04-13 /pmc/articles/PMC10133482/ /pubmed/37123410 http://dx.doi.org/10.3389/fcell.2023.1123446 Text en Copyright © 2023 Ishimoto, Gaffney and Smith. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Cell and Developmental Biology
Ishimoto, Kenta
Gaffney, Eamonn A.
Smith, David J.
Squirmer hydrodynamics near a periodic surface topography
title Squirmer hydrodynamics near a periodic surface topography
title_full Squirmer hydrodynamics near a periodic surface topography
title_fullStr Squirmer hydrodynamics near a periodic surface topography
title_full_unstemmed Squirmer hydrodynamics near a periodic surface topography
title_short Squirmer hydrodynamics near a periodic surface topography
title_sort squirmer hydrodynamics near a periodic surface topography
topic Cell and Developmental Biology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10133482/
https://www.ncbi.nlm.nih.gov/pubmed/37123410
http://dx.doi.org/10.3389/fcell.2023.1123446
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