Abstract
We point out unconventional mechanical properties of confined active fluids, such as bacterial suspensions, under shear. Using a minimal model of an active liquid crystal with no free parameters, we predict the existence of a window of bacteria concentration for which a suspension of E. Coli effectively behaves, at steady-state, as a negative viscosity fluid and reach a quantitative agreement with experimental measurements. Our theoretical analysis further shows that a negative apparent viscosity is due to a nonmonotonic local velocity profile, and it is associated with a nonmonotonic stress versus strain rate flow curve. This implies that fixed stress and fixed strain rate ensembles are not equivalent for active fluids.
Original language | English |
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Article number | 018001 |
Number of pages | 5 |
Journal | Physical Review Letters |
Volume | 121 |
Issue number | 1 |
Early online date | 3 Jul 2018 |
DOIs | |
Publication status | Published - 6 Jul 2018 |
Research Groups and Themes
- BrisSynBio
- Bristol BioDesign Institute
Keywords
- Escherichia coli/chemistry
- Liquid Crystals/chemistry
- Models, Biological
- Models, Chemical
- Models, Theoretical
- Suspensions
- Synthetic biology
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Dive into the research topics of 'Active Suspensions have Nonmonotonic Flow Curves and Multiple Mechanical Equilibria'. Together they form a unique fingerprint.Profiles
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Professor Tanniemola B Liverpool
- School of Mathematics - Professor of Theoretical Physics
- Fluids and materials
- Applied Mathematics
Person: Academic , Member, Group lead