title: Acoustic bubble sorting for ultrasound contrast agent enrichment.
abstract: An ultrasound contrast agent (UCA) suspension contains encapsulated microbubbles with a wide size distribution, with radii ranging from 1 to 10 μm. Medical transducers typically operate at a single frequency, therefore only a small selection of bubbles will resonate to the driving ultrasound pulse. Thus, the sensitivity can be improved by narrowing down the size distribution. Here, we present a simple lab-on-a-chip method to sort the population of microbubbles on-chip using a traveling ultrasound wave. First, we explore the physical parameter space of acoustic bubble sorting using well-defined bubble sizes formed in a flow-focusing device, then we demonstrate successful acoustic sorting of a commercial UCA. This novel sorting strategy may lead to an overall improvement of the sensitivity of contrast ultrasound by more than 10 dB.
authors.affiliation: Physics of Fluids Group and MESA+ Institute of Nanotechnology, P.O. Box 217, 7500 AE Enschede, The Netherlands. t.j.segers@utwente.nl.
authors.forename: Tim
authors.initials: T
authors.lastname: Segers
authors.forename: Michel
authors.initials: M
authors.lastname: Versluis
mesh_terms: D000162:Acoustics; D003287:Contrast Media / Q000737:chemistry*; D004867:Equipment Design; D056656:Lab-On-A-Chip Devices; D045423:Microbubbles; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation; D008962:Models, Theoretical; D014465:Ultrasonics
chemical_list: D003287:Contrast Media