A curvature-driven effective attraction in multicomponent membranes

TL;DR

This study reveals that in multicomponent membranes, geometric effects induce an effective attraction between phases with different spontaneous curvatures, influencing membrane patterning independently of direct component interactions.

Contribution

The paper demonstrates that curvature-driven effects can cause effective phase attraction in multicomponent membranes, a novel insight into membrane organization.

Findings

Effective attraction between phases with different spontaneous curvatures.

Robustness of the effect despite high line tension at interfaces.

Geometry-driven mechanism independent of direct component interactions.

Abstract

We study closed liquid membranes that segregate into three phases due to differences in the chemical and physical properties of its components. The shape and in-plane membrane arrangement of the phases are coupled through phase-specific bending energies and line tensions. We use simulated annealing Monte Carlo simulations to find low-energy structures, allowing both phase arrangement and membrane shape to relax. The three-phase system is the simplest one in which there are multiple interface pairs, allowing us to analyze interfacial preferences and pairwise distinct line tensions. We observe the system's preference for interface pairs that maximize differences in spontaneous curvature. From a pattern selection perspective, this acts as an effective attraction between phases of most disparate spontaneous curvature. We show that this effective attraction is robust enough to persist even when the interface between these phases is the most penalized by line tension. This effect is driven by geometry and not by any explicit component-component interaction.