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Three-Dimensional Mid-Air Acoustic Manipulation - Levitation

submitted by Zawash

1 decade 11 months 3 weeks ago

Extremely fascinating! From Engadget:
Ultrasonic levitation has been possible for awhile, but it's not very practical when objects must typically hover along a single axis. University of Tokyo researchers Yoichi Ochiai, Takayuki Hoshi and Jun Rekimoto have cleared this hurdle with an ultrasonic array that can push items around in 3D space. The machine creates a focal point from a three-dimensional standing wave; users just have to alter the wave's properties to move whatever is caught inside that point. The technique can manipulate a wide range of materials, and it's safe to disrupt with your hands. While the array will need to scale up before it lifts objects much larger than matchsticks or screws, it already shows that we don't need exotic technologies like tractor beams to float things through the air.

YT:
Three-Dimensional Mid-Air Acoustic Manipulation (2013-)

Yoichi Ochiai (The University of Tokyo)
Takayuki Hoshi (Nagoya Institute of Technology)
Jun Rekimoto (The University of Tokyo / Sony CSL)

http://96ochiai.ws/3DOFacoustic
contact: yoichi.ochiai@me.com

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 and, so far, this method has been used to levitate lightweight particles, small creatures, and water droplets.
The acoustic axis of the ultrasound beam in these previous studies was parallel to the gravitational force, and the levitated objects were manipulated along the fixed axis (i.e. one-dimensionally) by controlling the phases or frequencies of bolted Langevin-type transducers. In the present study, we considered extended acoustic manipulation whereby millimetre-sized particles were levitated and moved three-dimensionally by localised ultrasonic standing waves, which were generated by ultrasonic phased arrays. Our manipulation system has two original features. One is the direction of the ultrasound beam, which is arbitrary because the force acting toward its centre is also utilised. The other is the manipulation principle by which a localised standing wave is generated at an arbitrary position and moved three-dimensionally by opposed and ultrasonic phased arrays. We experimentally confirmed that various materials could be manipulated by our proposed method.

Yoichi Ochiai, Takayuki Hoshi, Jun Rekimoto: Three-dimensional Mid-air Acoustic Manipulation by Ultrasonic Phased Arrays arXiv:1312.4006 [physics.class-ph]
http://arxiv.org/abs/1312.4006