UChicago PME Materials Science Special Seminar - Jacob Klein, PH.D

Living cells experience spontaneous, transient electric fields across their membranes, which can lead to electroporation – enabling essential passage of ions – and cell-cell (or cell-vesicle) fusion, both crucial for cell viability. The implications for their interfacial - as opposed to biological - properties has not, to our knowledge, been examined. We discovered* that transmembrane electric fields can lead to a massive, reversible modulation of the sliding dissipation between surfaces coated with lipid bilayer membranes – a 200-fold variation, up to 2 orders-of-magnitude greater than achieved to date. Atomistic simulations reveal that the transverse fields, resembling those at cell membranes, lead to fully reversible electroporation of the confined bilayers, and formation of inter-bilayer bridges analogous to stalks preceding intermembrane fusion. These increase the interfacial dissipation through reduced hydration at the slip-plane, forcing it to revert in part from the low-dissipation, hydrated lipid-headgroups plane to the intra-bilayer, high-dissipation acyl tail interface. Our results demonstrate that lipid-bilayers under transmembrane electric fields can have striking materials-modification properties.