title: Microfluidic flow focusing: drop size and scaling in pressure versus flow-rate-driven pumping.
abstract: We experimentally study the production of micrometer-sized droplets using microfluidic technology and a flow-focusing geometry. Two distinct methods of flow control are compared: (i) control of the flow rates of the two phases and (ii) control of the inlet pressures of the two phases. In each type of experiment, the drop size l, velocity U and production frequency f are measured and compared as either functions of the flow-rate ratio or the inlet pressure ratio. The minimum drop size in each experiment is on the order of the flow focusing contraction width a. The variation in drop size as the flow control parameters are varied is significantly different between the flow-rate and inlet pressure controlled experiments.
authors.affiliation: Division of Engineering and Applied Sciences, Harvard University Cambridge, Cambridge, MA 02138, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Ward
authors.forename: Magalie
authors.initials: M
authors.lastname: Faivre
authors.forename: Manouk
authors.initials: M
authors.lastname: Abkarian
authors.forename: Howard A
authors.initials: HA
authors.lastname: Stone
mesh_terms: D046210:Microfluidic Analytical Techniques; D044085:Microfluidics; D011312:Pressure