Shape Instabilities in the Dynamics of a Two-component Fluid Membrane

TL;DR

This paper investigates how phase separation affects the shape dynamics of two-component fluid membranes, revealing different morphological behaviors depending on lipid mobility through simulation and Langevin modeling.

Contribution

It introduces a combined simulation and Langevin approach to study membrane shape instabilities driven by phase separation and lipid mobility.

Findings

High mobility causes labyrinthine patterns to break into buds that merge.

Low mobility leads to elastic buckling and crinkled surface morphology.

Phase separation influences membrane shape stability and morphology.

Abstract

We study the shape dynamics of a two-component fluid membrane, using a dynamical triangulation monte carlo simulation and a Langevin description. Phase separation induces morphology changes depending on the lateral mobility of the lipids. When the mobility is large, the familiar labyrinthine spinodal pattern is linearly unstable to undulation fluctuations and breaks up into buds, which move towards each other and merge. For low mobilities, the membrane responds elastically at short times, preferring to buckle locally, resulting in a crinkled surface.