Particulate and Emulsion Sorting Using Microfluidics

We report on a microfluidic device capable of sorting nanoscale particulates and water-in-oil emulsions at high-throughput. The device is passive, relying solely on hydrodynamic forces and the emulsion mass to achieve separation. We use the microfluidic device to deliver surfactants and lipids to the emulsion surface. This is achieved by immersing the emulsions in a fluid stream with a high concentration of the nano-particulates. The particulates assemble on the surface of the emulsions as they are transported along the stream. The emulsions are then transferred (i.e. separated) into a second fluid stream that is devoid of surrounding material. The performance of the device is evaluated for a range of flow rates, nano-particulate concentrations, and emulsion sizes. We report separation efficiencies that exceed current technologies over a wide range of flow rates. The microfluidic device can be used to produce delivery vehicles for pharmaceuticals and models for membrane biology studies.