A novel non-contact carrying and transportation method based on near-field acoustic levitation and negative pressure adsorption

A novel non-contact carrying and transportation technology is proposed based on near-field acoustic levitation (NFAL) and negative pressure adsorption effect. The disk-shaped objects can be levitated at a height of tens or even hundreds of micrometers, and a restoring force will be generated during the transportation process to make the object move toward the center of the acoustic emission plate, once the suspended object deviates from the center of the acoustic emission plate. A compact object stage is designed, and the coupling mechanism of near-field ultrasonic suspension force and hydrostatic vacuum adsorption force is revealed. The modal and harmonic response analysis of the acoustic emission unit of the object stage are carried out by using the finite element method to find the optimal operating parameters, and the impedance matching of the acoustic emission unit is carried out to improve the energy conversion efficiency. A prototype of the object stage is fabricated and assembled to verify the working performance. Ultimately, the experimental test environment is built to investigate the characteristics of the non-contact carrying and transportation system. The experimental results show that the acoustic emission unit produces the “N”-shaped ideal mode at the resonant frequency of 20190 Hz with the maximum vibration amplitude of 14.6 µm. The maximum bearing weight of the object stage is 470 g. The restoring force of the non-contact transportation system can reach 2.03 mN, which is 120.65% higher than the near-field acoustic levitation. In the equal time, the restoring distance of objects moving with different accelerations after eccentricity increases significantly, which contributes to improve the speed and efficiency of non-contact transportation system. The study on the non-contact carrying and transportation technology proposed in this article will provide a novel method for the transportation of precision components such as optical lenses, silicon wafers, etc.