Dynamic phase separation of fluid membranes with rigid inclusions

TL;DR

This study demonstrates through numerical simulations that membrane shape fluctuations can cause dynamic phase separation of membranes with rigid inclusions, with larger inclusions promoting stronger separation.

Contribution

It provides the first numerical evidence of fluctuation-driven phase separation in membranes with rigid inclusions, highlighting the role of inclusion size and elastic properties.

Findings

Shape fluctuations induce membrane phase separation.

Larger inclusions enhance separation tendency.

Large inclusions aggregate at low concentrations.

Abstract

Membrane shape fluctuations induce attractive interactions between rigid inclusions. Previous analytical studies showed that the fluctuation-induced pair interactions are rather small compared to thermal energies, but also that multi-body interactions cannot be neglected. In this article, it is shown numerically that shape fluctuations indeed lead to the dynamic separation of the membrane into phases with different inclusion concentrations. The tendency of lateral phase separation strongly increases with the inclusion size. Large inclusions aggregate at very small inclusion concentrations and for relatively small values of the inclusions' elastic modulus.