title: Ultrasound-induced microbubble coalescence.
abstract: We studied the interaction of ultrasound contrast agent bubbles coated with a layer of lipids, driven by 0.5 MHz ultrasound. High-speed photography on the submicrosecond timescale reveals that some bubbles bounce off each other, while others show very fast coalescence during bubble expansion. This fast coalescence cannot be explained by dissipation-limited film drainage rates. We conclude that the lipid shell ruptures upon expansion, exposing clean free bubble interfaces that support plug flow profiles in the film and inertia-limited drainage whose time scales match those of the observed coalescence.
authors.affiliation: Department of Experimental Echocardiography, Thoraxcentre, Erasmus MC, Rotterdam, The Netherlands. m.postema@erasmusmc.nl
authors.forename: Michiel
authors.initials: M
authors.lastname: Postema
authors.forename: Philippe
authors.initials: P
authors.lastname: Marmottant
authors.forename: Charles T
authors.initials: CT
authors.lastname: Lancée
authors.forename: Sascha
authors.initials: S
authors.lastname: Hilgenfeldt
authors.forename: Nico
authors.initials: N
authors.lastname: de Jong
mesh_terms: D003287:Contrast Media; D045423:Microbubbles; D008962:Models, Theoretical; D010316:Particle Size; D010781:Photography / Q000379:methods; D014465:Ultrasonics
chemical_list: D003287:Contrast Media