Sustentator (acoustic levitation)

Title: Sustentateur (Acoustic sustainer)
Signature : Project in partnership with students in their fourth year of engineering school specialising in physical engineering and embedded systems
Year: 2021

This object is the result of a collaboration with engineering students. Their objective was to create a device that would enable acoustic levitation based on the physical phenomenon of standing waves. Together, we re-evaluated our objectives in order to create an attractive, impressive object capable of levitating small objects, but whose main function would be to be used as a scientific demonstration object.

The concept is based on the fact that sound waves, as they propagate through the medium in which they are emitted, create phases of compression and expansion. When a sound is emitted, it exerts pressure. This pressure is measured in Pascal and corresponds to the amplitude of the sound wave.

Standing waves are phenomena that occur when acoustic waves propagate simultaneously in opposite directions, with identical frequencies and amplitudes in the same medium. Standing waves do not “propagate”; they create zones of compression and decompression that remain fixed. It is therefore possible to trap small objects in what are known as “pressure nodes”.

In this object, transducers (loudspeakers) located facing each other produce ultrasound at a frequency of 40 kHz, levitating small polystyrene balls at the centre of the object.