The undulation force; theoretical results versus experimental demonstrations

Håkan Wennerström; Ulf Olsson

doi:10.1016/j.cis.2014.02.010

The undulation force; theoretical results versus experimental demonstrations

Adv Colloid Interface Sci. 2014 Jun:208:10-3. doi: 10.1016/j.cis.2014.02.010. Epub 2014 Feb 20.

Authors

Håkan Wennerström¹, Ulf Olsson²

Affiliations

¹ Division of Physical Chemistry, Department of Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden. Electronic address: hakan.wennerstrom@fkem1.lu.se.
² Division of Physical Chemistry, Department of Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden. Electronic address: ulf.olsson@fkem1.lu.se.

PMID: 24607002
DOI: 10.1016/j.cis.2014.02.010

Abstract

In 1978 Wolfgang Helfrich published a paper (Helfrich W. Z Naturforsch 1978; 33a:305) where he introduced the notion of an undulation force between bilayers. This is caused by thermal excitations of the bending modes being restricted by the presence of neighboring layers. Although there is now a consensus on the qualitative picture put forward by Helfrich there is still a debate concerning the quantitative aspects. We discuss in particular the distance dependence of the interaction and also the value of the numerical coefficient of the force law derived by Helfrich.

Keywords: Fluid membranes.