Three-Dimensional Mid-Air Acoustic Manipulation [Acoustic Levitation] (2013,2014-)

Three-Dimensional Mid-Air Acoustic Manipulation (2013,2014-) Yoichi Ochiai
Sound wave 3Dvolution: Japanese scientists move objects using acoustic levitation
n order to move expanded polystyrene particles of 0.6 mm and 2 mm in diameter, the Japanese scientists at the University of Tokyo and the Nagoya Institute of Technology had to place the objects inside a complex set-up of four arrays of speakers. Using a refinement of the existing technology of sound wave management, bubbles, a screw and a tiny piece of wood were airlifted and moved around in all direction within the experiment’s confines.
“The essence of levitation technology is the countervailing of gravity. It is known that an ultrasound standing wave is capable of suspending small particles at its sound pressure nodes,” Yoichi Ochiai from University of Tokyo said.

Currently, acoustic levitators are used mostly in industry and for researchers of anti-gravity effects such as at NASA.