Stability of biomimetic membranes in DC electric fields

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 a DC electric field. 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.