P5B-8 Self-Trapping of Microbubbles to Surface of Target

A novel method of self-trapping of micro bubbles is proposed in order to trap the bubbles to the surface of target. This method uses micro bubble aggregation between an actual bubble and the mirror bubble that is located at symmetry position for the surface of the target. Nonlinear oscillation of micro bubble in conjunction with the secondary ultrasonic wave radiated from the bubble produces the Bjerknes force which acts as a trapping force to the target surface. Once the bubble is trapped, the nonlinear oscillation of already trapped bubble promotes the further tapping to the target surface. A condition for minimum separation between the neighboring bubbles is derived, which is required to start the trapping. Experiments are carried out using contrast agent micro bubbles. Silicone resin and agar gel phantoms are examined as targets.