Acoustic Levitation Signals New Wave in Lifting

This might work as a tractor beam in space....I still don't have a read on the energy required to levitate matter...ie: watts per gram......but I think they are still tweaking the frequency...

http://arxiv.org/ftp/arxiv/papers/1312/1312.4006.pdf

"In space, no one can hear you scream."

I think you need to have air.

Possibly laser generated ultrasonic waves...? The waves being used are ultrasonic in nature, they cannot be heard....

http://extras.springer.com/2003/978-0-7354-0117-4/cdr_pdfs/indexed/305_1.pdf

No air (or other medium), no sound. Not even ultrasound.

Well if the laser light is used to vibrate the material at ultrasonic frequencies, it might have the control effect of steering something....no?

" The physical principle is of thermal expansion (also called thermoelastic regime) or ablation. In the thermoelastic regime the ultrasound is generated by the sudden thermal expansion due to the heating of a tiny surface of the material by the laser pulse. If the laser power is sufficient to heat the surface above the material boiling point, some material is evaporated (typically some nanometres) and ultrasound is generated by the recoil effect of the expanding material evaporated. In the ablation regime, a plasma is often formed above the material surface and its expansion can make a substantial contribution to the ultrasonic generation. consequently the emissivity patterns and modal content are different for the two different mechanisms."

http://en.wikipedia.org/wiki/Laser_ultrasonics

No medium, no sound. End of. May be able to move a grain of sand in space by radiation pressure, given a sufficiently powerful laser and enough time, or maybe by boiling some of the surface away and using the vapour as a kind of jet, but that's it. No tractor beam. Sorry.

Then what are they talking about in the "conclusions" statement at the end of the study....

"Conclusion

In conclusion, we have demonstrated an extended acoustic manipulation by which millimetre-sized

particles can be levitated and moved three-dimensionally by localised ultrasonic standing waves

generated by ultrasonic phased arrays. In addition to the presented examples, we also tested other

small objects such as a feather and droplets of alcohol and a colloidal solution.

In a future work, we will use 25 kHz transducers instead of the 40 kHz type. Then the 4-mm node

intervals by 40 kHz transducers will be extended to 8 mm. This would enable the manipulation of

larger particles.

It has not escaped our notice that our developed method for levitation under gravity suggests the

possibility of developing a technology for handling objects under microgravity."

http://arxiv.org/ftp/arxiv/papers/1312/1312.4006.pdf

A micro-gravity environment does not have to be a vacuum environment. For this sound based technique to work in micro-gravity there must be an atmosphere to move.

Where does a micro-gravity environment exist that has an atmosphere?

Really, I have to name the obvious.

The International Space Station has an atmosphere.

Well for one thing I thought that was zero gravity...for another I don't see much room for this type of equipment....

For another, it's quite noisy on the space station....

http://gizmodo.com/5971285/in-space-nobody-can-hear-you-scream-because-its-fcking-noisy

What would be the use of such technology in the space station?

To again state the obvious, this is not my project and I have never been to the space station. I have no stake or inside knowledge in this research at all. Thus my answer is just a WAG.

I know that one of the problems they've encountered in micro-gravity fabrication experiments is any tweezer or other tool used to manipulate the fabricated widget deforms the widget. This ultra-sound movement technique might allow manipulation without deformation.

Your haughty derision is a wasted effort here, however I thank you for your time and effort....

Oh, the more accurate term is micro-gravity. "Zero gravity" implies the incorrect idea gravity does not exist. If gravity didn't exist then the station would not be in orbit around the Earth, Sun, etc.

In micro-gravity you would not need as much power to move objects. It would need to impart only small amounts of acceleration and not overcoming 1g earth gravity. So I expect it could be made more compact for use in space.

What Fred sed.

A surprise crash of cymbals could be levitating. Just scale up to 10⁶ decibels....

If I crank Up my sound system I can raise the neighbors....

Interesting! I wonder if this is how they make a hover board?

Can't remember his name, but 15-20 years ago, an acoustic/rf experimenter was doing this with bowling balls in his garage. Had his equipment confiscated several times and was labeled a 'kook'. I'll look up notes when I get home and repost.