Lipid membrane instability and poration driven by capacitive charging

A new model for the interaction of an electric pulse with a lipid membrane is proposed. Using this model we show that when a DC electric pulse is applied to an insulating lipid membrane separating fluids with different conductivities, the capacitive charging current through the membrane drives electrohydrodynamic flow that destabilizes the membrane. The instability is transient and decays as the membrane charges. The bulk conductivity mismatch plays an essential role in this instability because it results in a different rate of charge accumulation on the membrane's physical surfaces. Shearing stresses created by the electric field acting on its own induced free charge are non-zero as long as the charge imbalance exists. Accordingly, the most unstable mode is related to the ratio of membrane charging time and the electrohydrodynamic time.