Gas-Dynamic Virtual Nozzle for Generation of Microscopic Droplet Streams

Background
The Gañán-Calvo method for utilizing a “virtual nozzle” to produce very small diameter columnar liquid jets is currently the state of the art in the field. This method involves passing a gaseous fluid entraining a liquid fluid through a capillary tube and out an aperture at the end. The gas-dynamic forces exerted by the gaseous fluid provide the “virtual nozzle” that reduces the liquid flow diameter well below that of the aperture diameter. While the Gañán-Calvo method improves markedly over conventional solid walled converging nozzles by offering reduced liquid flow diameters and reduced incidence of clogging, it cannot render droplet diameters in the micrometer/sub-micrometer range.
Invention Description
Researchers at Arizona State University have developed an improved Gas-Dynamic Virtual Nozzle (“GDVN”) that refines the Gañán-Calvo method to produce superior columnar liquid jets. Specifically, the ASU GDVN offers significantly smaller capillary, orifice, and droplet dimensions, single-file microscopic streams, in situ alignment, and miniaturization. Likewise, the ASU GDVN can run the flow through a second capillary before or instead of a conventional aperture. The ASU GDVN is particularly useful for applications where the liquids of interest are complex aqueous solutions containing macromolecules or biospecies due to the increased risks of clogging that result when converting these particles to micrometer sizes.