Europhys. Lett.
Volume 70, Number 3, May 2005
Page(s) 404 - 410
Section Interdisciplinary physics and related areas of science and technology
Published online 06 April 2005
Europhys. Lett., 70 (3), pp. 404-410 (2005)
DOI: 10.1209/epl/i2004-10501-2

Spontaneous flow transition in active polar gels

R. Voituriez1, J. F. Joanny1 and J. Prost1, 2

1  Physicochimie Curie (CNRS-UMR168), Institut Curie, Section de Recherche 26 rue d'Ulm, 75248 Paris Cedex 05, France
2  ESPCI - 10 rue Vauquelin, 75231 Paris Cedex 05, France

received 15 December 2004; accepted in final form 17 March 2005
published online 6 April 2005

We study theoretically the effects of confinement on active polar gels such as the actin network of eukaryotic cells. Using generalized hydrodynamics equations derived for active gels, we predict, in the case of quasi-one-dimensional geometry, a spontaneous flow transition from a homogeneously polarized immobile state for small thicknesses, to a perturbed flowing state for larger thicknesses. The transition is not driven by an external field but by the activity of the system. We suggest several possible experimental realizations.

87.10.+e - Biological and medical physics: General theory and mathematical aspects.
83.80.Lz - Physiological materials (e.g. blood, collagen, etc.).
61.25.Hq - Macromolecular and polymer solutions; polymer melts; swelling.

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