It has been discovered that objects can levitate with the help of sound!

acoustic-levitation-2A team of researchers from Switzerland has developed a way to levitate and transport small objects, just with the help of sound

Using ultrasonic waves – the frequency of which is too high to be perceived by human hearing – scientists from the Swiss Federal Institute of Technology in Zurich were able to move in the air along a plane: water drops, instant coffee crystals, polystyrene flakes, even a toothpick, among other objects, making them interact with each other. It’s the first time researchers have been able to use a sound to simultaneously levitate multiple objects and make them interact with each other.

water levitationThe study, published in the Studies of the Swiss National Academy of Sciences, describes how objects placed between two horizontal surfaces, the bottom one that emits high frequency sound waves and the top one that reflects the waves back, can levitate and be manipulated.

Even a teenager with a subwoofer knows that sound waves exert pressure. When these waves are reflected back between carefully aligned surfaces, they can create what is known as the “standing wave”, in which the total pressure in the original wave and its reflection cancel each other out. Objects placed on certain places along the wave with the slightest amplitude, known as node points, tend to remain in place.

In the past, scientists were able to acoustically levitate polystyrene flakes, very small insects even fish. But, so far, no one has noticed how to hold objects in the air with the help of acoustic waves, just placing them in their field of action.
“Theoretically, there is no difference between theory and practice,” says engineer Daniel Foresti, author of the study presented above, in a recent interview “But in practice, it exists!”



Scroll to Top