Osmotic imbalance methods for bilayer formation

An apparatus for forming a plurality of lipid bilayers over an array of cells in a nanopore based sequencing chip, the system comprising:

• a nanopore based sequencing chip comprising an array of cells, each of the cells comprising a well;
• a flow channel over the array of cells;
• and
• a processor and memory for storing instructions that, when executed by the processor, is configured to:
• flow a first salt buffer solution with a first osmolarity through the flow channel and over a cell in the nanopore based sequencing chip to substantially fill a well in the cell with the first salt buffer solution;
• flow a lipid and solvent mixture through the flow channel and over the cell to deposit a lipid membrane over the well that encloses the first salt buffer solution in the well;
• and
• flow a second salt buffer solution with a second osmolarity through the flow channel and above the well, wherein the second osmolarity is a lower osmolarity than the first osmolarity such that an osmotic imbalance is created between a first volume inside the well and a second volume outside the well, wherein the osmotic imbalance causes water to diffuse through the lipid membrane into the well, thereby causing the lipid membrane to bow upwards and extend into the flow channel;
• and
• flowing the second salt buffer solution over the bowed lipid membrane to reduce the thickness of the lipid membrane to form a lipid bilayer.