Vesicle dynamics in uniform electric fields: squaring and breathing

We computationally investigate the dynamics of a vesicle exposed to uniform DC or AC electric fields. We employ the two-dimensional boundary integral method in order to simulate vesicle deformation under experimental conditions where peculiar drum-like ("squared'') shapes have been observed. The vesicle membrane is modeled as an infinitely thin, capacitive, area-incompressible interface, with the surrounding fluids acting as leaky dielectrics. Our simulations capture the "squaring'' phenomenon, in which vesicles deform into rectangular profiles with corner-like regions of high curvature, as vesicles undergo dynamic transitions between oblate and prolate ellipsoidal shapes.