Sound waves have managed to levitate and move particles a la carte

2013/07/16 Etxebeste Aduriz, Egoitz - Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Ingeniaritza
• Fisika

Using sound waves, the engineers of the Swiss Federal Institute of Technology (ETHZ) have managed, in addition to lebiting small particles and drops of liquid, to move freely through the air. The new technique has been published in PNAS magazine.

Electromagnetism is most commonly used for levitation. But this only works for metals or magnetic materials, for example, does not affect a drop of water. However, sound waves do not have this problem, so researchers have long been working with sound wave levitation. The concept is simple: the sound waves emitted upwards are reflected on a surface and go back down. Thus, the waves that are directed up and down cancel each other at a central point where an object can be “trapped”, as the waves simultaneously push it up and down.

So far this technique has not been applied, since the only thing that could be achieved was to keep the objects at a point. Now, however, Swiss researchers have managed to mobilize objects. Several sound wave emission platforms have been placed together that have managed to move objects to their liking by changing the frequency they emit. And more than one at a time, for example, against one another.