Light-controlled flows in active fluids
Type de document :
Compte-rendu et recension critique d'ouvrage
DOI :
Titre :
Light-controlled flows in active fluids
Auteur(s) :
Dervaux, Julien [Auteur]
Matière et Systèmes Complexes [MSC]
Resta, Marina [Auteur]
Brunet, Philippe [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Matière et Systèmes Complexes [MSC]
Resta, Marina [Auteur]
Brunet, Philippe [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Titre de la revue :
Nature Physics
Pagination :
306-312
Éditeur :
Nature Publishing Group
Date de publication :
2017-03
ISSN :
1745-2473
Discipline(s) HAL :
Physique [physics]/Matière Condensée [cond-mat]/Matière Molle [cond-mat.soft]
Science non linéaire [physics]/Adaptation et Systèmes auto-organisés [nlin.AO]
Physique [physics]/Mécanique [physics]/Mécanique des fluides [physics.class-ph]
Science non linéaire [physics]/Adaptation et Systèmes auto-organisés [nlin.AO]
Physique [physics]/Mécanique [physics]/Mécanique des fluides [physics.class-ph]
Résumé en anglais : [en]
Many photosynthetic microorganisms are able to detect light and move toward optimal intensities. This ability, known as phototaxis, plays a major role in ecology by affecting natural phytoplankton mass transfers and has ...
Lire la suite >Many photosynthetic microorganisms are able to detect light and move toward optimal intensities. This ability, known as phototaxis, plays a major role in ecology by affecting natural phytoplankton mass transfers and has important applications in bioreactor and artificial microswimmers technologies. Here we show that this property can be exploited to generate macroscopic fluid flows using a localized light source directed toward shallow suspensions of phototactic microorganisms. Within the intensity range of positive phototaxis, algae accumulate beneath the excitation light where collective effects lead to the emergence of radially symmetric convective flows. These flows can thus be used as hydrodynamic tweezers to manipulate small floating objects. At high cell density and layer depth, we uncover a new kind of instability wherein the viscous torque exerted by self-generated fluid flows on the swimmers induces the formation of traveling waves. A model coupling fluid flow, cell concentration and orientation finely reproduces the experimental data.Lire moins >
Lire la suite >Many photosynthetic microorganisms are able to detect light and move toward optimal intensities. This ability, known as phototaxis, plays a major role in ecology by affecting natural phytoplankton mass transfers and has important applications in bioreactor and artificial microswimmers technologies. Here we show that this property can be exploited to generate macroscopic fluid flows using a localized light source directed toward shallow suspensions of phototactic microorganisms. Within the intensity range of positive phototaxis, algae accumulate beneath the excitation light where collective effects lead to the emergence of radially symmetric convective flows. These flows can thus be used as hydrodynamic tweezers to manipulate small floating objects. At high cell density and layer depth, we uncover a new kind of instability wherein the viscous torque exerted by self-generated fluid flows on the swimmers induces the formation of traveling waves. A model coupling fluid flow, cell concentration and orientation finely reproduces the experimental data.Lire moins >
Langue :
Anglais
Vulgarisation :
Non
Source :
Fichiers
- https://hal.archives-ouvertes.fr/hal-02326433/document
- Accès libre
- Accéder au document
- https://hal.archives-ouvertes.fr/hal-02326433/document
- Accès libre
- Accéder au document
- https://hal.archives-ouvertes.fr/hal-02326433/document
- Accès libre
- Accéder au document
- document
- Accès libre
- Accéder au document
- phototactic-chlamy-HAL.pdf
- Accès libre
- Accéder au document