Ultrasonic acoustic levitation

[mikeselectricstuff]

This was fun...

[Lightages]

Yeah, that looked like fun!

I think that you could have a better transducer for air. It would seem to me that the transducer you were using was optimized for coupling to a stainless steel tank with a water like liquid inside. The acoustical impedance of air is very much different so I believe that lump of aluminum is not optimum of transferring the acoustic energy to the air.

Just a thought.

[mikeselectricstuff]

Yeah, that looked like fun!

I think that you could have a better transducer for air. It would seem to me that the transducer you were using was optimized for coupling to a stainless steel tank with a water like liquid inside. The acoustical impedance of air is very much different so I believe that lump of aluminum is not optimum of transferring the acoustic energy to the air.

Just a thought.

Quite probably - if nothing else it probably wants to be a smoother surface. However it may be hard to couple more efficiently while maintaining planarity

[Berni]

Very nice! I didn't think ultrasonic levitation was this easy to do, surprisingly stable as well. But I bet any cats and dogs around your house hated you for blasting out such a loud screech.

Would it also help to put this thing inside a tube so that the waves can't disperse out as much? Levitation does look more impressive in as much free air as possible on the other hand.

Oh and it might be possible to make it automatically track it's resonant point if you use a small piezo speaker next to it as a microphone and use a comparator to generate the drive signal so it self oscillates.

[mikeselectricstuff]

Very nice! I didn't think ultrasonic levitation was this easy to do, surprisingly stable as well. But I bet any cats and dogs around your house hated you for blasting out such a loud screech.

Would it also help to put this thing inside a tube so that the waves can't disperse out as much? Levitation does look more impressive in as much free air as possible on the other hand.

Did think of that but not tried - I suspect you'd get interference from waves bouncing off the walls

Oh and it might be possible to make it automatically track it's resonant point if you use a small piezo speaker next to it as a microphone and use a comparator to generate the drive signal so it self oscillates.

It's easier than that - you just make it adjust fo rmaximum power draw

[Psi]

I wonder what would happen if you sanded some polystyrene and used the dust.
Static would probably be an issue.


Also, superglue might be an interesting but messy liquid to try.

[firewalker]

Cool demo of standing waves.

Can a transducer like the one you are using to scare a nearby dog barks all day and night?

Alexander.

[amyk]

Mike's Electrophysics Stuff.

This transducer looks similar to the one you have, and is rated up to 120C:
http://www.steminc.com/piezo/PZ_BLTViewPN.asp?PZ_Type=BOLT CLAMPED LANGEVIN&PZ_SM_MODEL=SMBLTD45F28H

[brainwash]

Quite appropriate, I have a dog at a house nearby that barks all day and night. I'm on the 15th floor and still able to hear him clearly, so he might want to hear this as well.

I was thinking maybe some pulverized alcohol or other lightweight liquid (propane, butane) might be able to form droplets where needed. Also, experimenting at lower temperatures will yield a higher air density. Also, water vapor has significantly less density than liquid water.
http://en.wikipedia.org/wiki/Density_of_air#Water_vapor

[EpicIntelGamer]

Hello Mike!

I've been watching your videos for quite a few months and I had no idea you were on this forum, this is awesome to be able to talk to you!

Although slightly hard for me to understand, I think this Ultrasonic Levitation is some of the coolest stuff I've ever seen!

I hope you keep at it and get it to the point where you can levitate water droplets like you wanted to.

[SgrA]

Hello everybody!

Thanks for the cool project and the well-explained video, I'm planning to try this out. What transformer is it, and what is the idea behind using the secondary for the driver circuit and the primary for the load?

EDIT: Does it have something to do with impedance matching, as a 1:1 transformer?

Thanks!

[amyk]

This reminds me, a possibly interesting teardown subject is a dental ultrasonic scaler (also known as "dental woodpeckers" on eBay), if you manage to acquire one.

[codeboy2k]

Thanks Mike.. That looked like fun..

Aside from the fun factor, is there any commercial use of ultrasonic levitation? 

[SgrA]

Aside from the fun factor, is there any commercial use of ultrasonic levitation? 

Acoustic levitation has been used for 'containerless' processing of corrosive chemicals or vigorous reactions, and also for research in effects of anti-gravity by NASA. http://en.wikipedia.org/wiki/Acoustic_levitation

[codeboy2k]

thanks for the link..

note to self: check Wikipedia before posting