Scientists in Spain and England have successfully used an ultrasonic speaker to make an object levitate. Not only that, they were able to control the movement of the object, making it spin and move around in a controllable manner. Now, admittedly, the object in question is just a tiny tiny ball about 1mm across but it is still an impressive feat to achieve this using nothing more than sound waves.
Some reports have described the device as being like a tractor beam because there is some video footage of the bead being pulled up towards the speaker, but it could just as easily push things away so I’m not sure why they picked up on this one detail other than the fact that it sounds super cool. Which it does.
This same effect has been achieved before but then the object had to be completely surrounded by speakers and be blasted from all directions at once, this time there is just the one speaker and that makes this a far more practically applicable technology. The authors of the paper, published in Nature Communications, suggest several possible downstream applications, the length of the list boosted somewhat by the fact that this levitation could be achieved in liquids and even biological tissues not just the air. For example, drugs could be guided to and held in the correct position within the body to be most effective; there’s the prospect of containerless transportation; and the technique would also be useful in manipulating cells and in crystallography and could even be used to levitate living things.
Below you can see a video from the researchers that demonstrates the effect. They model the sound waves in real time as a kind of hologram of the acoustic structure that holds the beads in place. Different holograms have different effects and can be used in combination to manipulate the ball as you see fit.
Every now and then I come across a new piece of science that really blows me away, normally because it is in a field that I didn’t even know existed. Who knew that there were people out there trying to make things fly through the air using nothing more than sound? I, for one, am impressed.