Reproducible reformation of a bilayer lipid membrane using microair bubbles

Planar bilayer lipid membranes (BLMs) are widely used as models for cell membranes in various applications, including drug discovery and biosensors. However, the nanometer-thick bilayer structure, assembled through hydrophobic interactions of amphiphilic lipid molecules, makes such BLM systems mechanically and electrically unstable. In this study, we developed a device to reform BLMs using a microair bubble. The device consists of a double well divided by a separator with a microaperture, where a BLM was formed by infusing a lipid-dispersed solvent and an aqueous droplet into each well in series. When the BLM ruptured, a microair bubble was injected from the bottom of the well to split the merged aqueous droplet at the microaperture, which resulted in the reformation of two lipid monolayers on the split droplets. By bringing the two droplets into contact, a new BLM was formed. An angled step design was introduced in the BLM device to guide the bubble and ensure the splitting of the merged droplet. We also elucidated the optimal bubble inflow rate for the reproducible BLM reformation. Using a 4-channel parallel device, we demonstrated the individual and repeatable reformation of BLMs. Our approach will aid the development of automated and arrayed BLM systems.