article · 22/08/2016
Active Particles with Soft and Curved Walls: Equation of State, Ratchets, and Instabilities
Résumé
We study, from first principles, the pressure exerted by an active fluid of spherical particles on general boundaries in two dimensions. We show that, despite the nonuniform pressure along curved walls, an equation of state is recovered upon a proper spatial averaging. This holds even in the presence of pairwise interactions between particles or when asymmetric walls induce ratchet currents, which are accompanied by spontaneous shear stresses on the walls. For flexible obstacles, the pressure inhomogeneities lead to a modulational instability as well as to the spontaneous motion of short semiflexible filaments. Finally, we relate the force exerted on objects immersed in active baths to the particle flux they generate around them.
Citer cet article
Nikola, N., Solon, A.-P., Kafri, Y., Kardar, M., Tailleur, J., & Voituriez, R. (2016). Active Particles with Soft and Curved Walls: Equation of State, Ratchets, and Instabilities. PHYSICAL REVIEW LETTERS, 117(9). https://doi.org/10.1103/PhysRevLett.117.098001@article{Nikola2016_172,
author = {Nikola, Nikolai and Solon, Alexandre P. and Kafri, Yariv and Kardar, Mehran and Tailleur, Julien and Voituriez, Raphael},
year = {2016},
month = {8},
title = {Active Particles with Soft and Curved Walls: Equation of State, Ratchets, and Instabilities},
journal = {PHYSICAL REVIEW LETTERS},
volume = {117},
number = {9},
abstract = {We study, from first principles, the pressure exerted by an active fluid of spherical particles on general boundaries in two dimensions. We show that, despite the nonuniform pressure along curved walls, an equation of state is recovered upon a proper spatial averaging. This holds even in the presence of pairwise interactions between particles or when asymmetric walls induce ratchet currents, which are accompanied by spontaneous shear stresses on the walls. For flexible obstacles, the pressure inhomogeneities lead to a modulational instability as well as to the spontaneous motion of short semiflexible filaments. Finally, we relate the force exerted on objects immersed in active baths to the particle flux they generate around them.},
url = {http://www.dx.doi.org/10.1103/PhysRevLett.117.098001},
doi = {10.1103/PhysRevLett.117.098001},
issn = {0031-9007},
}TY - JOUR
AU - Nikola, Nikolai
AU - Solon, Alexandre P.
AU - Kafri, Yariv
AU - Kardar, Mehran
AU - Tailleur, Julien
AU - Voituriez, Raphael
PY - 2016
DA - 2016/08/22
TI - Active Particles with Soft and Curved Walls: Equation of State, Ratchets, and Instabilities
JO - PHYSICAL REVIEW LETTERS
VL - 117
IS - 9
SN - 0031-9007
AB - We study, from first principles, the pressure exerted by an active fluid of spherical particles on general boundaries in two dimensions. We show that, despite the nonuniform pressure along curved walls, an equation of state is recovered upon a proper spatial averaging. This holds even in the presence of pairwise interactions between particles or when asymmetric walls induce ratchet currents, which are accompanied by spontaneous shear stresses on the walls. For flexible obstacles, the pressure inhomogeneities lead to a modulational instability as well as to the spontaneous motion of short semiflexible filaments. Finally, we relate the force exerted on objects immersed in active baths to the particle flux they generate around them.
DO - 10.1103/PhysRevLett.117.098001
UR - http://www.dx.doi.org/10.1103/PhysRevLett.117.098001
ER -