Scientists invent "tractor beam"

[Brian G Turner]

http://www.bbc.co.uk/news/science-environment-34647921

Engineers in Bristol have developed a system that can grab, hold and move small objects without touching them, using "holograms" made of sound waves.

It offers the kind of remote control that naturally draws comparison with the "tractor beams" of science fiction.

So far the team has tested the design on small pea-sized objects, which they can manipulate from 30-40cm away.

Unfortunately, as sound requires a medium to propagate through, this method will probably be of little use for dragging ships through space against their will.

 

[Ray McCarthy]

Dreaded BBC having a slow news day?
It's also done with lasers for smaller objects, which works in a vacuum.Optical Tweezers
It's not much like SF tractor beams at all, as it's very weak, short range and needs atmosphere. This isn't new.
It's not likely to be scalable to much larger. Acoustic tweezers. Not Tractor beams

 

[Serendipity]

Dreaded BBC having a slow news day?
It's also done with lasers for smaller objects, which works in a vacuum.Optical Tweezers
It's not much like SF tractor beams at all, as it's very weak, short range and needs atmosphere. This isn't new.
It's not likely to be scalable to much larger. Acoustic tweezers. Not Tractor beams

There is another mechanism that can work with lasers in vacuum. When that laser ricochets (glancing blow for the non-techies) off a body, then the pressure from the laser will turn that body. Get the configuration and it can look like it is acting like a tractor beam.

 

[Ray McCarthy]

Please forgive my acidic scepticism in previous post...

Here is more
http://www.theregister.co.uk/2015/10/28/brit_boffins_build_tractor_beam_out_of_sound/

That array of loudspeakers is depicted in the video below and the remarkable thing about it is that they're all in the one unit: previous attempts at this kind of thing have required more than one speaker array.

That's the novel bit, not acoustic tweezers.

 

[Ursa major]

Speaking in my role as honorary consul for the folks back in Ursa Major, I have a question.

Can anyone tell me if this tractor beam can be scaled up? It's just that they have this bl**dy great plough but no way of pulling it....

 

[Ray McCarthy]

if this tractor beam can be scaled up?

Not much. Power is an issue
A trombone is about 3W acoustic power.
A speaker might need 300W input for same energy. This may be ultrasound where efficiencies are worse

Any mass or friction of significance needs a lot of power. Look at power of small car engine. You'd need kilowatts (maybe 100,000 watts acoustic power or 10,000,000 Watts electrical power ) to move or levitate a person 30cm away. Possibly the object could easily be damaged.

This is for potentially mico manipulation inside a body, kidney stones, a drug etc. Very low power, low range "wireless" tweezers.

 

[Stephen Palmer]

Nobody yet has mentioned the Wurzels.

 

[BAYLOR]

It will revolutionize farming .

 

[J Riff]

I saw The Acoustic Tweezers live, the Wurzels were opening act.

 

[BAYLOR]

The Tractor Beams. Now this would be a great name for a rock and roll band.