Levitation technology steps up its game

In another step towards creating Back to the Future's hoverboards and Star Trek’s holodecks, scientists from the University of São Paulo in Brazil have found a way to improve existing levitation technology.

 

Published in the journal Applied Physics Letters, the device can levitate small particles of polystyrene using reflected sound waves. The sound waves are emitted from a source above a concave reflector. By changing the orientation of the reflector, you can move around the hovering particle.

 

This development is an important step towards building devices that can be used to handle things like hazardous or sensitive materials.

 

“Modern factories have hundreds of robots to move parts from one place to another,” said Marco Aurélio Brizzotti Andrade, lead researcher. “Why not try to do the same without touching the parts to be transported?”

 

The device that Andrade and his colleagues developed was able to levitate small particles. According to them, the next step is to be able to levitate heavier materials.

 

Typically, the setup includes an upper cylinder that will emit high-frequency sound waves that are reflected back from a concave bottom. The reflected waves interact with the emitted waves and produce “standing waves,” which have nodes. If the acoustical pressure at these nodes is strong enough, it can allow an object to float by counteracting the force of gravity.

 

Previously, scientists at the University of Tokyo have invented a way to levitate and manipulate particles in mid-air. Their approach allowed the researchers to move the suspended particles in all three dimensions.

 

Earlier similar devices required a precise maintained distance between the emitter and reflector (equal to a multiple of half a wavelength of the sound waves) to enable them to levitate anything and the particles were in a fixed position. The newer devices allowed researchers to not only levitate particles but to also transport them across short distances.

 

The device developed by Andrade’s team doesn’t need a maintained distance between the emitter and reflector. According to Andrade, the distance can be changed even in mid-flight without the levitating particle being affected.

 

“Just turn the levitator on and it is ready,” Andrade said. — Bea Montenegro/TJD, GMA News