Fig. 3.
(a) The bubble with a radius of 30–33 μm oscillates at the 5th harmonious mode at 100 kHz. (b) The bubble oscillates between the statuses represented by blue and red lines. The arrow indicates the point used to measure the oscillating amplitude. (c) The change in position of bubble’s surface (Arrowin Fig. 3b), the bubble oscillates at the same frequency as the stimulating acoustic waves with an amplitude of 2 μm; the surface velocity was calculated as 0.8 m/s. (d) The amplitude of acoustic radiation force. (e) The ratio between maximum drag force and radiation force.