Flexoelectric fluid membrane vesicles in spherical confinement

TL;DR

This study numerically investigates how external electric fields influence the shape and folding patterns of flexoelectric fluid membrane vesicles confined in spheres, revealing electric field-induced shape transitions and potential applications.

Contribution

It introduces a numerical analysis of electric field effects on confined flexoelectric vesicles, highlighting shape transitions and symmetry breaking not previously characterized.

Findings

Electric fields induce elongation and shape transitions in vesicles.

Higher surface area and electric field strength lead to complex folding.

Transition lines shift under electric field influence.

Abstract

The morphology of spherically confined flexoelectric fluid membrane vesicles in an external uniform electric field is studied numerically. Due to the deformations induced by the confinement, the membrane becomes polarized resulting in an interaction with the external field. The equilibrium shapes of the vesicle without electric field can be classified in a geometrical phase diagram as a function of scaled area and reduced volume [1,2]. When the area of the membrane is only slightly larger than the area of the confining sphere, a single axisymmetric invagination appears. A non-vanishing electric field induces an additional elongation of the confined vesicle which is either perpendicular or parallel depending on the sign of the electric field parameter. Higher values of the surface area or the electric field parameter can reduce the symmetry of the system leading to more complex folding. We present the resulting shapes and show that transition lines are shifted in the presence of an electric field. The obtained folding patterns could be of interest for biophysical and technological applications alike.