Role of disclinations in determining the morphology of deformable fluid interfaces

TL;DR

This study explores how disclinations influence the shape of deformable fluid interfaces with nematic order, revealing defect-driven morphologies like tubes and discs through Monte Carlo simulations.

Contribution

It demonstrates that anisotropic curvature and nematic disclinations can spontaneously generate complex vesicle shapes, highlighting the role of defect interactions in membrane morphology.

Findings

Disclinations induce formation of tubes and discs in vesicles.

Defect interactions drive morphological transitions like tube formation.

Helical membrane arrangements emerge as a dominant soft mode.

Abstract

We study the equilibrium shapes of vesicles, with an in-plane nematic order, using a Monte-Carlo scheme and show that highly curved shapes, like tubes and discs, with a striking similarity to the structures engendered by certain curvature sensing peripheral membrane proteins, can be spontaneously generated by anisotropic directional curvature with nematic disclinations playing and important role. We show that the coupling between nematic order and local curvature could lead to like defects moving towards each other and unlike defects moving away, in turn leading to tube formation. Thermally induced defect pair production lead to branched tubular structures. It is also shown that helical arrangement of the membrane tubes, with nematic field spiraling around it, is a dominant soft mode of the system.