title: Upstream Swimming in Microbiological Flows.
abstract: Interactions between microorganisms and their complex flowing environments are essential in many biological systems. We develop a model for microswimmer dynamics in non-Newtonian Poiseuille flows. We predict that swimmers in shear-thickening (-thinning) fluids migrate upstream more (less) quickly than in Newtonian fluids and demonstrate that viscoelastic normal stress differences reorient swimmers causing them to migrate upstream at the centerline, in contrast to well-known boundary accumulation in quiescent Newtonian fluids. Based on these observations, we suggest a sorting mechanism to select microbes by swimming speed.
authors.affiliation: The Rudolf Peierls Centre for Theoretical Physics, 1 Keble Road, Oxford OX1 3NP, United Kingdom.
authors.forename: Arnold J T M
authors.initials: AJ
authors.lastname: Mathijssen
authors.affiliation: The Rudolf Peierls Centre for Theoretical Physics, 1 Keble Road, Oxford OX1 3NP, United Kingdom.
authors.forename: Tyler N
authors.initials: TN
authors.lastname: Shendruk
authors.affiliation: The Rudolf Peierls Centre for Theoretical Physics, 1 Keble Road, Oxford OX1 3NP, United Kingdom.
authors.forename: Julia M
authors.initials: JM
authors.lastname: Yeomans
authors.affiliation: The Rudolf Peierls Centre for Theoretical Physics, 1 Keble Road, Oxford OX1 3NP, United Kingdom.
authors.forename: Amin
authors.initials: A
authors.lastname: Doostmohammadi
mesh_terms: D060833:Cellular Microenvironment; D008827:Microbiological Phenomena; D008954:Models, Biological; D013550:Swimming / Q000502:physiology*; D055682:Viscoelastic Substances
chemical_list: D055682:Viscoelastic Substances