  It is well known that lipid membranes respond to a threshold transmembrane
electric field through a reversible mechanism called electroporation, where
hydrophilic water pores form across the membrane, an effect widely used in
biological systems. The effect of such fields on interfacially-confined
(stacked or supported) lipid membranes, on the other hand, which may strongly
modulate interfacial properties, has not to our knowledge been previously
studied. Motivated by recent surface forces experiments showing a striking
effect of electric fields on lubrication by confined lipid bilayers, we carried
out all-atom molecular dynamics simulations of such membranes under transverse
electric fields. We find that in addition to electroporation, a new feature
emerges of locally merged bilayers which act to bridge the confining
interfaces. These features shed light on the remodelling of confined lipid
membrane stacks by electric fields, and provides insight into how such fields
may modulate frictional and more generally surface interactions in the presence
of lipid-based boundary layers.
