Periodic lipidic membrane tubesF. Campelo1, J.-M. Allain2, 3 and M. Ben Amar2
1 Departament d'Estructura i Constituents de la Matèria, Facultat de Física, Universitat de Barcelona - Diagonal 647, E-08028 Barcelona, Spain
2 Laboratoire de Physique Statistique, École Normale Supérieure - 24 rue Lhomond, F-75231 Paris Cedex 05, France
3 Biomedical Engineering Department, Boston University - 44 Cummington Street, Boston, MA 02215, USA
received 25 July 2006; accepted in final form 11 December 2006; published February 2007
published online 1 February 2007
We investigate the formation of two-phase lipidic tubes of membrane in the framework of the Canham-Helfrich model. The two phases have different elastic moduli (bending and Gaussian rigidity), different tensions and a line tension prevents the mixing. For a set of parameters close to experimental values, periodic patterns with arbitrary wavelength can be found numerically. A wavelength selection is detected via the existence of an energy minimum. When the chemical composition induces an important enough size disequilibrium between both phases, a segregation into two half infinite tubes is preferred to a periodic structure.
87.16.Dg - Membranes, bilayers, and vesicles.
87.10.+e - Biological and medical physics: general theory and mathematical aspects.
68.03.Cd - Surface tension and related phenomena.
© Europhysics Letters Association 2007