Precision Engineering of Micrometer and Nanometer Droplets for Ultrasound Imaging and Therapy

The medical community has interest in improving techniques such as occlusion, therapeutics and imaging through the use of liquid perfluorocarbon droplets. The ability to create a monodispersed population of liquid perfluorocarbon droplets would have the added advantage of uniform acoustic activation parameters. A microfluidic device with a flow-focusing orifice allowed for uniform production of perfluoropentane droplets in the micron and submicron diameter range. These droplets are able to be stored for over two weeks while retaining distribution characteristics. The observed activation of the droplets shows the acoustic threshold as a function of droplet diameter with little variability. Results showed that microfluidic technology with a pressure controlled flow regulator will allow for greater manufacturing control of phase-change perfluorocarbons in the micron and sub-micron size range for acoustic droplet vaporization applications.