Ultrasound is a vibration at frequencies beyond the upper limit of human hearing (f >20 kHz). It is generated by transducers which are powered by separate power electronics.
Using the squeeze film levitation significant repelling forces can be generated between the sound source and the workpiece. Therefore the workpiece can be moved without any friction. The force profile is similar to that of a conventional air bearing. However no compressed air-supply is necessary. The ultrasound technology uses the ambient air or (process) gas at the interface for the pressure generation.
The physics of the ultrasonic suspension derives more from fluid dynamics than from acoustic principles. The gas pressure in the gap between the workpiece and the vibrating surface of the sound generator rises due to the cyclic compression and decompression of the thin gas film. Therefore it is necessary to create a uniform vibration pattern in order to generate equal levitation forces through- out the whole vibrating surface. This is one of the core competences of ZS-Handling: we trim the sound!