Eur. Phys. J. E 14, 387-394 (2004)
DOI: 10.1140/epje/i2004-10020-6

Fluid membranes exchanging material with external reservoirs

P. Girard¹, F. Jülicher² and J. Prost<sup>1, 3

1</sup>  Physico-Chimie Curie, UMR CNRS-Institut Curie 168, 26 rue d'Ulm, F-75248 Paris Cedex 05, France
²  Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Straße 38, D-01187 Dresden, Germany
³  Ecole Supérieure de Physique et de Chimie Industrielles, 10 rue Vauquelin, F-75231 Paris Cedex 05, France

philippe.girard@curie.fr
julicher@mpipks-dresden.mpg.de
jacques.prost@curie.fr

(Received 30 March 2004 / Published online: 31 August 2004)

Abstract
We investigate the dynamics of a single component fluid bilayer, which exchanges material with the surrounding fluid. We derive covariant equations of motion taking into account solvent permeation, exchange of lipids between solvent and the membrane and discuss the sources of noise in these equations. Different lipid concentrations on both sides of the membrane lead to a non-equilibrium state. We discuss steady states as well as shape instabilities which occur at a critical osmotic-pressure difference.

PACS
05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion.
87.16.Ac - Theory and modelling; computer simulation.
87.16.Dg - Membranes, bilayers, and vesicles.

© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2004