Europhys. Lett.
Volume 68, Number 4, November 2004
Page(s) 596 - 602
Section Interdisciplinary physics and related areas of science and technology
Published online 27 October 2004
Europhys. Lett., 68 (4), pp. 596-602 (2004)
DOI: 10.1209/epl/i2004-10248-8

The soft-mode instability of a membrane induced by strong polymer adsorption

Wokyung Sung1, 2 and SeungKyun Lee1

1  Department of Physics, Pohang University of Science and Technology Pohang 790-784, S. Korea
2  Asia Pacific Center for Theoretical Physics - Pohang 790-784, S. Korea

received 29 June 2004; accepted in final form 29 September 2004
published online 27 October 2004

The interaction between a flexible polymer and a fluctuating membrane is a fundamental problem in soft-matter physics with relevance to biological phenomena occurring in cells. We find that polymer fluctuations in a strongly adsorbed state can renormalize the bending rigidity of a planar membrane to a negative value. It gives rise to a novel phenomenon that the membrane with a small surface tension can be unstable to spontaneous formation of a soft mode, i.e., a large-amplitude undulation with the wavelength comparable to the interaction range which can be long.

87.16.Dg - Membranes, bilayers, and vesicles.
61.25.Hq - Macromolecular and polymer solutions; polymer melts; swelling.

© EDP Sciences 2004