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

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

Corresponding author: wsung@postech.ac.kr

Received: 29 June 2004
Accepted: 29 September 2004

Abstract

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.