Events Calendar

Aerospace and Mechanical Engineering Seminar Series

Speaker: Ran Gabai, Dynamics and Mechatronics Laboratory, Faculty of Mechanical Engineering, Technion IIT, Haifa, Israel

Talk Title: Acoustic Levitation and Propulsion Based on Traveling Waves Control

Series: Aerospace and Mechanical Engineering Seminar Series

Abstract: Acoustic levitation is generated by inducing ultrasonic vibrations to a surface above which a levitated object is held by elevated pressure. A thin film of gas separating the vibrating surface and the levitated body exhibits both rapid fluctuations and a rise in the average pressure. An application being researched currently involves the handling of silicon wafers in clean rooms with no mechanical contact thus eliminating a significant contamination sources. The elevated pressure is capable of levitating objects weighting several kg by a vibrating surface 100mm in diameter. By creating a traveling pressure wave, it is possible to add propelling forces to the levitating component thus creating a contactless transportation system. By sensing the position of the levitated object one can control, in a closed loop feedback scheme, the levitation height and the planar position and orientation.
The dynamics of the mechanical structure has to be carefully tailored to enhance the electromechanical efficiency leading to sufficient amplitudes of the ultrasonic vibrations to provide appropriate levels of acoustic levitation and traveling waves. Ultrasonic structural traveling waves are generated by exciting two modes of vibrations that are tuned, in real time, to generate the required traveling wave direction and amplitude. Small structural uncertainties spoil the symmetry of the structure and detune the conditions for traveling waves. Therefore, an optimization process is introduced to experimentally map the exact traveling wave excitation conditions.
This work presents the analytical background, numerical simulations, and several experimental set-ups validating the applicability of acoustic levitation and propulsion.

Biography: Ran Gabai is a post-doctoral researcher at the Dynamics and Mechatronics Laboratory at the Technion working with Prof. Izhak Bucher. He earned his PhD (2008) at the Faculty of Mechanical engineering at the Technion as well as his M.S. (2003) and B.S. (2000). His research focuses on dynamic and vibrations, mechatronics, signal processing, control, and embedding digital brains in dynamical systems. Dr. Gabai is the co-founder and CTO of a start-up company developing a Coriolis-based mass flow meter.

Location: Seaver Science Library (SSL) - 150

Audiences: Everyone Is Invited

Contact: Valerie Childress