Not something you see every day

[Tom Danley]

A former co-worker sent me a link for something cool (I always thought it was anyway) acoustic levitation. The link has a nice video of it.

I had invented / developed the transducers and control electronics for this back in the 80’s and 90’s when I worked at Intersonics (a small NASA contractor). We flew an acoustic levitation furnace on a couple shuttle flights (STS-7 and STS-51a).

One can levitate starting at about 155dB, this system is working at about 22KHz and an array of 6 of the transducers can literally light a cigarette with acoustic friction (at about 175dB).

A funny thing, we levitated several bugs with this, a cockroach being most humorous, he was very confused.

Scientists use levitation to create better pharmaceuticals with fewer side effects


Best
Tom Danley
Danley Sound Labs

[winslow]

I saw a guy doing some acoustic levitation on TV a couple of weeks back. They showed the levitation chamber, I recognized the drivers being used- BMS 4540s. Was using a 21k hertz signal.

[onebadmonte]

This would me a sure fire way to get kids to take their cough medicine.

[jwmbro]

Originally Posted by onebadmonte

This would me a sure fire way to get kids to take their cough medicine.

The high pressure high frequency sound, while of no importance to the middle aged scientests, may be very annoying to kids at the age where they are reluctant to take cough medicine.

I don't think I could work at that lab, my HF hearing is still far too good. I'd have to suspend it with 30kHz waves.

[weltersys]

Originally Posted by Tom Danley

One can levitate starting at about 155dB, this system is working at about 22KHz and an array of 6 of the transducers can literally light a cigarette with acoustic friction (at about 175dB).

Tom Danley
Danley Sound Labs

Tom,

I recall seeing your acoustic levitator, coolest thing ever!

After getting some severe tinnitus after mixing some ultrasonic tones:
What are benefits of adding HF driver 7khz up?

post #179 and #182

The tones, though both ultrasonic, generate an audible beat frequency sub tone.
I read after the experiment that ultrasonic tones in the 20K range still cause hearing damage, even though (to me) inaudible.

How loud was your acoustic levitator outside of the focal point (say at 2-3 feet) when running at 175 dB?

Art Welter