article · 15/09/2017
Generalized Archimedes' principle in active fluids
Résumé
We show how a gradient in the motility properties of noninteracting pointlike active particles can cause a pressure gradient that pushes a large inert object. We calculate the force on an object inside a system of active particles with position-dependent motion parameters, in one and two dimensions, and show that a modified Archimedes' principle is satisfied. We characterize the system, both in terms of the model parameters and in terms of experimentally measurable quantities: the spatial profiles of the density, velocity and pressure. This theoretical analysis is motivated by recent experiments, which showed that the nucleus of a mouse oocyte (immature egg cell) moves from the cortex to the center due to a gradient of activity of vesicles propelled by molecular motors; it more generally applies to artificial systems of controlled localized activity.
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Razin, N., Voituriez, R., Elgeti, J., & Gov, N.-S. (2017). Generalized Archimedes' principle in active fluids. PHYSICAL REVIEW E, 96(3). https://doi.org/10.1103/PhysRevE.96.032606@article{Razin2017_168,
author = {Razin, Nitzan and Voituriez, Raphael and Elgeti, Jens and Gov, Nir S.},
year = {2017},
month = {9},
title = {Generalized Archimedes' principle in active fluids},
journal = {PHYSICAL REVIEW E},
volume = {96},
number = {3},
abstract = {We show how a gradient in the motility properties of noninteracting pointlike active particles can cause a pressure gradient that pushes a large inert object. We calculate the force on an object inside a system of active particles with position-dependent motion parameters, in one and two dimensions, and show that a modified Archimedes' principle is satisfied. We characterize the system, both in terms of the model parameters and in terms of experimentally measurable quantities: the spatial profiles of the density, velocity and pressure. This theoretical analysis is motivated by recent experiments, which showed that the nucleus of a mouse oocyte (immature egg cell) moves from the cortex to the center due to a gradient of activity of vesicles propelled by molecular motors; it more generally applies to artificial systems of controlled localized activity.},
url = {http://www.dx.doi.org/10.1103/PhysRevE.96.032606},
doi = {10.1103/PhysRevE.96.032606},
issn = {2470-0045},
}TY - JOUR
AU - Razin, Nitzan
AU - Voituriez, Raphael
AU - Elgeti, Jens
AU - Gov, Nir S.
PY - 2017
DA - 2017/09/15
TI - Generalized Archimedes' principle in active fluids
JO - PHYSICAL REVIEW E
VL - 96
IS - 3
SN - 2470-0045
AB - We show how a gradient in the motility properties of noninteracting pointlike active particles can cause a pressure gradient that pushes a large inert object. We calculate the force on an object inside a system of active particles with position-dependent motion parameters, in one and two dimensions, and show that a modified Archimedes' principle is satisfied. We characterize the system, both in terms of the model parameters and in terms of experimentally measurable quantities: the spatial profiles of the density, velocity and pressure. This theoretical analysis is motivated by recent experiments, which showed that the nucleus of a mouse oocyte (immature egg cell) moves from the cortex to the center due to a gradient of activity of vesicles propelled by molecular motors; it more generally applies to artificial systems of controlled localized activity.
DO - 10.1103/PhysRevE.96.032606
UR - http://www.dx.doi.org/10.1103/PhysRevE.96.032606
ER -