A Droplet Interface Bilayer (DIB) is formed when nano litre aqueous droplets are contacted together in an oil solution in the presence of phospholipids. A lipid monolayer forms at each oil-water interface, and by bringing together two monolayers a bilayer is created. This method opens up a range of new experiments for interrogating membrane protein function. Foremost of these is the ability to perform simultaneous single-molecule optical imaging and single-channel electrical recording.

A number of recent advances in our lab extending this technology enables us to modulate two-dimensional protein concentration and membrane curvature. Manipulation of the axial position of the droplet relative to a hydrogel substrate controls the size of the bilayer formed at the interface; this enables the surface density of integral membrane proteins to be controlled. We are able to modulate the surface density of the beta-barrel pore-forming toxin alpha-hemolysin over a range of 4 orders of magnitude within a timeframe of a few seconds.