The present paper deals with the dynamics of planar objects levitated by means of near field acoustic levitation. Nowadays, the microelectronics industry handles and transports silicon wafers in clean rooms using conveyers, chucks and robotic arms that physically hold the wafers. The physical contact between the wafers and the abovementioned mechanisms creates particles which contaminate the wafers and the work environment. The need to reduce these contaminations can be addressed by employing the near field acoustic levitation phenomenon, where generation of ultrasonic vibrations produces load carrying forces due to the compressibility and the viscosity of the ambient gas. These forces can levitate the wafers without any physical contact. In order to integrate acoustic levitation based devices in the microelectronics industry, a highly accurate and efficient positioning ability has to be realized. For this sake it is necessary to establish rapid and precise control algorithms. Due to the high complexity of the existing models describing the levitation mechanism, a simplified analytical model is vital for devising control strategies. Indeed, development of a simplified analytical model that describes merely the slow evolution of the levitated object, given the enforced rapid oscillations, is introduced in this paper. Next, after a satisfactory comparison to numerical simulations, an experimental validation of the approximated analytical model is carried. This validation examines the correlation between the analytical and the experimental results at steady-state and also during the transient response.
