Scientists Use Sound Waves to Levitate, Move Objects

Innovative device lets researchers manipulate things with the help of sound waves

By Laura Sinpetru on July 16th, 2013 20:11 GMT

A new study published in the journal Proceedings of the National Academy of Sciences details how scientists in Switzerland have succeeded in using acoustic levitation to lift objects from the ground and make them move.

Acoustic levitation, otherwise known as acoustophoretic contactless transport and handling of matter in air, is science-talk for the ability to use sound waves to make things float about a room, maybe even crash into one another.

The scientific community has long been aware of the fact that one could use sound waves to move things.

In fact, acoustic levitation is considered by many as a noteworthy alternative to electromagnetism, a levitation technique that boils down to using magnetic forces to counter gravity and make various object move through the air.

The only problem was that, until recently, trying to controlling sound waves in ways that would lead to acoustic levitation proved a rather futile endeavor.

Nature reports that the Swiss researchers have figured out a way to create a device that not only achieves acoustic levitation, but is also capable to juggle two or more objects with different weights and densities at the same time.

So far, they have managed to make water droplets, coffee granules, fragments of polystyrene and a toothpick fly about simultaneously.

“We present a unique acoustophoretic concept for the contactless transport and handling of matter in air.”

“Spatiotemporal modulation of the levitation acoustic field allows continuous planar transport and processing of multiple objects, from near-spherical (volume of 0.1–10 μL) to wire-like, without being limited by the acoustic wavelength,” the scientists write in their paper.

This technology could one day be used to try out potentially hazardous chemical reactions.

By mixing and matching chemical reactants with the help of acoustic levitation, researchers would keep nearby surfaces or containers free from contamination.

Check out the video below to see sound waves pushing sodium and water together.
Swiss researchers use sound waves to levitate things
   Swiss researchers use sound waves to levitate things