Acoustic Levitation Works On Small Animals

anthemaniac writes "Researchers for at least two decades have used acoustic levitation to suspend light materials without a container. Wenjun Xie, a materials physicist at Northwestern Polytechnical University in China, has previously used ultrasound fields to levitate globs of iridium and mercury, very heavy materials. Now the scientist has performed the feat with live animals. From the story: 'Xie and his colleagues employed an ultrasound emitter and reflector that generated a sound pressure field between them. The emitter produced roughly 20-millimeter-wavelength sounds, meaning it could in theory levitate objects half that wavelength or less.' Apparently the ants, spiders and ladybugs endured the trick just fine, but the fish didn't do so well due to lack of water."

Comments

Re:Biological heating effects?

[Red Flayer]

Well, ultrasound is used to create the field... but the emitter that produces the waves for levitation has waves of much, much longer wavelength (and therefore much lower frequency). I think instead of at the molecular level, the concern would be at the macro level... that is, can animal tissue deal with rapid mechanical manipulation from the soundwaves?

And is it possible for animals to have cavities or structures with a resonant frequency equal to that of the emitted waves? That's where the real danger lies, I think.

Re:50 Hz?

[cnettel]

Ehum, only if sound travelled 1 meter per second in air. Hint: it doesn't. It's more like 340, hence the frequency is 50 * 340 = 17,000 Hz.