Researchers have demonstrated that it is possible to stably trap objects larger than the wavelength of sound in an acoustic tractive beam. In theory, it could lift a human body ...
Acoustic tractors use sound waves to manipulate solid or liquid objects without touching them. Until now, researchers working on acoustic levitation felt that it could only be applied to very small objects or microparticles. Indeed, tests with objects larger than the wavelength did not work properly. Because the rotation of the sound field ends up being transmitted to the object which will turn more and more quickly until being ejected.
But researchers at the University of Bristol (UK) have found a solution that they believe could even be used to levitate a human body. The concept is based on the creation of acoustic vortices using transducers whose structure takes the form of a tornado that encloses a silent core. By modifying this structure, researchers have managed to trap objects larger than what has been done so far.
