Curriculum of Applied Sciences and Engineering-Materials Science, The University of North Carolina, Chapel Hill, NC 27599, USA.
Ultrasound Med Biol. 2011 Nov;37(11):1952-7. doi: 10.1016/j.ultrasmedbio.2011.08.012. Epub 2011 Oct 2.
Liquid perfluorocarbon droplets have been of interest in the medical acoustics community for use as acoustically activated particles for tissue occlusion, imaging and therapeutics. To date, methods to produce liquid perfluorocarbon droplets typically result in a polydisperse size distribution. Because the threshold of acoustic activation is a function of diameter, there would be benefit from a monodisperse population to preserve uniformity in acoustic activation parameters. Through use of a microfluidic device with flow-focusing technology, the production of droplets of perfluoropentane with a uniform size distribution is demonstrated. Stability studies indicate that these droplets are stable in storage for at least two weeks. Acoustic studies illustrate the thresholds of vaporization as a function of droplet diameter, and a logarithmic relationship is observed between acoustic pressure and vaporization threshold within the size ranges studied. Droplets of uniform size have very little variability in acoustic vaporization threshold. Results indicate that microfluidic technology can enable greater manufacturing control of phase-change perfluorocarbons for acoustic droplet vaporization applications.
液体全氟碳滴在医学声学领域引起了人们的兴趣，可作为声激活颗粒用于组织闭塞、成像和治疗。迄今为止，生产液体全氟碳滴的方法通常会导致多分散的粒径分布。由于声激活的阈值是直径的函数，因此使用单分散群体将有助于保持声激活参数的一致性。通过使用具有流聚焦技术的微流控装置，展示了具有均匀粒径分布的全氟戊烷液滴的生产。稳定性研究表明，这些液滴在储存至少两周内是稳定的。声学研究说明了作为液滴直径函数的汽化阈值，并且在研究的尺寸范围内观察到声压和汽化阈值之间的对数关系。具有均匀尺寸的液滴在声汽化阈值方面的变化非常小。结果表明，微流控技术可以实现相变全氟碳的更大制造控制，用于声液滴汽化应用。
