High speed camera images of bubble surface modes appearing in Sonovue microbubbles, n = 3,4,5 from left to right. Each image represents a different bubble of approximately 10 μm in size, being driven in a 0.5 MHz acoustic field. Images were taken in-house on a Cordin 550 (Cordin Company, Salt Lake City, UT) at 2 Mfps.
(Color online) Simulation of bubble surface modes using surface harmonics displayed in polar plot (upper) and area plots (lower). The amplitude of the shaded area represents anYn m (θ,ϕ). (Showing in terms of r,θ for m = 0 only.)
(Color online) Oscillations of the second surface mode in a 2.9 μm bubble insonated at 1.7 Mhz. (a) Driving p-n acoustic pressure at 170 kPa; (b) radial oscillations when driven at 170 kPa; (c) second mode amplitude when driven at 170 kPa; (d) second mode amplitude when driven at 400 kPa, where simulation stops when the second mode amplitude of the bubble exceeds its initial radius.
Simulation of bubble surface modes with varying bubble size and acoustic pressure. The color bar, in logarithmic scale, represents the number of pulses taken for the given surface mode to become larger than the initial bubble size. Left: shelled bubbles; right: shell free bubbles; top: n = 2; middle: n = 3; bottom: n = 4. Performed at 1.7 MHz using the shell parameters listed in Sec. IV. Note that a value of 100 infers that the bubble was not overwhelmed in surface mode oscillations during the simulated 100 pulses.
(Color online) 3.5 μm bubble driven at 1.7 MHz, 425 kPa (top), and 450 kPa (bottom). Period doubling behavior in the radial oscillations at the higher driving pressure (bottom) damps the build up of surface mode oscillations.
List of parameter values used for simulations.
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