Two-dimensional acoustic manipulation in air using interference of standing wave field by three sound waves

Abstract

A number of small ultrasonic transducers were placed on a flat surface to form a directional ultrasonic sound source. A standing wave field with a hexagonal distribution of sound pressure like a honeycomb was formed when ultrasonic waves were superimposed from three directions using three of these sources. Small objects could be trapped at the nodes of the sound pressure in the sound field. When the phase of the three sources was changed, the sound pressure distribution shifted in the direction of the sound axis of the sources, and the objects trapped in the pressure nodes also shifted. For more stable object trapping, the ultrasonic transducers were placed on the inner wall of a semicylinder and the ultrasonic waves were focused to form a thin two-dimensional planar standing wave field. Three of these sources were used in the experiment, and it was possible to manipulate the objects more stably.

Experimental conditions for efficient retention of vascular endothelial cells on channel wall using lipid bubbles and acoustic interference

“…Furthermore, to reduce the interferential fringe of the retained cells, we investigated the effect of sweeping the distribution of interferential acoustic field. [27][28][29] In this paper, we report the efficient retention of vascular endothelial cells using phase sweeping of an interferential acoustic field, which was extended our preliminary study 21) by varying the velocity and the direction of sweeping.…”

“…15) Although floating LBs damage cells when they collapse under ultrasound exposure, the adherence of LBs to the cells is supposed to protect cells from damage. 15,16,29)…”

Pulse compression of guided wave by airborne ultrasound excitation for improving defect detection accuracy in concrete

“…Many non-destructive inspection [1][2][3][4] methods using ultrasound [5][6][7] have been studied with the goal of developing a quantitative method of inspection. Generally, this method uses a contact-type inspection device.…”