279193 Electrohydrodynamic Instabilities of Bilayer Membranes

Wednesday, October 31, 2012: 1:15 PM
410 (Convention Center )
Jacopo Seiwert1, Paul F. Salipante1, Michael Miksis2 and Petia M. Vlahovska1, (1)School of Engineering, Brown University, Providence, RI, (2)ESAM, Northwestern University, Chicago, IL

The interface defining a biological cell is a thin membrane, which acts as a leaky capacitor. We investigate the influence of capacitance and conductivity on the stability of a planar membrane subjected to  DC or AC electric fields, typically used in cell electroporation. We develop a zero-thickness model of the membrane, in which the bilayer finite thickness is effectively accounted for by membrane electro-mechanical properties such as bending modulus, capacitance and conductance. The linear stability analysis shows that membrane conductance and asymmetry in the embedding electrolyte solutions destabilize the interface. However, the capacitive charging acts to stabilize the system under conditions where an ordinary fluid- fluid interface is unstable. We also find that while a purely capacitive membrane is linearly stable in DC fields,  it can become unstable in AC fields. We identify the frequency correspoding to the most unstable mode and correlate it with the membrane charging time. Finally, the instability can lead to vesicle burst, and the timescale of collapse shows a t~1/E^2 dependence.

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See more of this Session: Interfacial and Nonlinear Flows II
See more of this Group/Topical: Engineering Sciences and Fundamentals