Mechanical instability generates monodisperse colloidosomes

TL;DR

This paper investigates how mechanical instability in colloidal membranes leads to the formation of uniform, permeable colloidosomes, offering insights into membrane dynamics and a scalable platform for various applications.

Contribution

It introduces a scaled-up colloidal membrane model that visualizes membrane instability and predicts vesicle formation, advancing understanding of membrane topological transitions.

Findings

Instability drives formation of monodisperse colloidosomes

Theoretical predictions match experimental instability points

Size of colloidosomes controlled by gravity and membrane thickness

Abstract

Formation and rupture of vesicles is a fundamental process underlying diverse phenomena in biology, materials science, and biomedical applications. Vesicles form when the area of a growing disk-like membrane exceeds a critical value at which the edge and bending energies balance each other. Observing such topological transitions in lipid bilayers is a challenge because of their nanoscale dimensions and rapid dynamics. We study a scaled-up model of colloidal membranes assembled from rod-shaped colloidal particles. The unique features of colloidal membranes enable the real-time visualization of spontaneous closure driven by instability relevant to all membrane-based materials. First-principles theory quantitatively predicts the instability point for vesicle formation and intermediate membrane conformations during the disk-to-vesicle transition. The instability generates monodisperse, selectively permeable colloidosomes with size controlled by gravity and membrane thickness, providing a scalable and programmable platform for diverse applications.