Spatially Selective Manipulation of Supported Lipid Bilayers by Laminar Flow: Steps Toward Biomembrane Microfluidics†

The ability to manipulate supported lipid bilayers after formation on a substrate has made possible new classes of both molecular and cellular level experiments. In this report, we combine the unique properties of these lipid systems with laminar flow concepts to selectively remove, collect, and reconstitute lipid bilayers from specified regions of a surface. A stream of detergent solution was directed over a preformed bilayer, resulting in the removal of bilayer material; mixing between adjacent flows at low Reynolds number is diffusion limited, providing confinement of this stripping solution and, consequently, bilayer removal with precision on the order of several micrometers. The freshly exposed surface allows formation of new connected bilayer when exposed to lipid vesicles. In conjunction with surface micropatterning and electrophoretic manipulation, we further demonstrate a first-generation, membrane-based separation/purification strategy. Flow-based manipulation of lipid bilayers forms the basis o...