Reference : Statistics of Colloidal Suspensions Stirred by Microswimmers
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Physics
http://hdl.handle.net/10993/41618
Statistics of Colloidal Suspensions Stirred by Microswimmers
English
Ortlieb, Levke []
Rafai, Salima []
Peyla, Philippe []
Wagner, Christian mailto [University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Physics and Materials Science Research Unit >]
John, Thomas []
2019
Physical Review Letters
American Physical Society
122
14
Yes (verified by ORBilu)
0031-9007
1079-7114
New York
NY
[en] We present a statistical analysis of the experimental trajectories of colloids in a dilute suspension of the green algae Chlamydomonas reinhardtii. The measured probability density function (pdf) of the displacements of colloids covers 7 orders of magnitude. The pdfs are characterized by non-Gaussian tails for intermediate time intervals, but nevertheless they collapse when scaled with their standard deviation. This diffusive scaling breaks down for longer time intervals and the pdf becomes Gaussian. However, the mean squared displacements of tracer positions are linear over the complete measurement time interval. Experiments are performed for various tracer diameters, swimmer concentrations, and mean swimmer velocities. This allows a rigorous comparison with several theoretical models. We can exclude a description based on an effective temperature and other mean field approaches that describe the irregular motion as a sum of the fluctuating far field of many microswimmers. The data are best described by the microscopic model by J.-L. Thiffeault, Distribution of particle displacements due to swimming microorganisms, Phys. Rev. E 92, 023023 (2015).
http://hdl.handle.net/10993/41618
10.1103/PhysRevLett.122.148101

File(s) associated to this reference

Fulltext file(s):

FileCommentaryVersionSizeAccess
Limited access
2019PRLChlamy.pdfPublisher postprint891.16 kBRequest a copy

Bookmark and Share SFX Query

All documents in ORBilu are protected by a user license.