title: The influence of compliant boundary proximity on the fundamental and subharmonic emissions from individual microbubbles.
abstract: The proximity of a solid-liquid boundary has been theoretically predicted to affect nonlinear microbubble emissions, but to date there has been no experimental validation of this effect. In this study, individual microbubbles (n = 15) were insonicated at f = 11 MHz as a function of offset distance from a compliant (agarose) planar boundary by employing an optical trapping apparatus. It was found that fundamental scattering increases while subharmonic scattering decreases as the microbubble approaches the boundary. Although a microbubble-boundary model can predict the qualitative trends observed for a subset of encapsulation properties, further modeling efforts are required to completely model compliant boundary-microbubble interactions.
authors.affiliation: Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada brandonhelfield@gmail.com, bleung@sri.utoronto.ca, goertz@sri.utoronto.ca.
authors.forename: Brandon L
authors.initials: BL
authors.lastname: Helfield
authors.affiliation: Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada brandonhelfield@gmail.com, bleung@sri.utoronto.ca, goertz@sri.utoronto.ca.
authors.forename: Ben Y C
authors.initials: BY
authors.lastname: Leung
authors.affiliation: Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada brandonhelfield@gmail.com, bleung@sri.utoronto.ca, goertz@sri.utoronto.ca.
authors.forename: David E
authors.initials: DE
authors.lastname: Goertz
mesh_terms: D000162:Acoustics; D003198:Computer Simulation; D004548:Elasticity; D045423:Microbubbles; D009038:Motion; D017711:Nonlinear Dynamics; D009716:Numerical Analysis, Computer-Assisted; D012542:Scattering, Radiation; D013016:Sound; D013500:Surface Tension; D014783:Viscosity