Experimental Study And Design Of Suspend Tool In Near-field Acoustic Levitation

Currently, there is a high demand for surface roughness and cleanliness in the field of precision machining and processing, such as silicon transportation in semiconductor industry. Thus, the traditional contact handling and transporting method is certainly defective. On the other hand, the non-contact transportation using Near-field Acoustic Levitation (NFAL), however, can keep the products from scratches and stains. In the NFAL, the suspended tool which can amplify the input displacement and function as a radiator on the output side plays a significant role in the whole system. Consequently, its structure directly influences the effect of levitation.In this paper, the NFAL is mainly discussed, aiming at study the levitation characteristics of NFAL phenomenon and analyzing the relationship between the dimension of the suspended tool and the stability of levitation. In addition, theoretical model of the suspended tool has been established according to the horn design theory and plate flexural vibration theory. Moreover, the finite element method and numerical analysis method are deployed to research the dynamic property of the suspended tool. The major researches include:1. By complete experiment, the relationships among the dimension of suspended tool, the dimension of suspended object and the levitation condition are detailed analyzed. Then the dimensional range of the circular planar which can stable levitate is acquired.2. Combining the horn design theory with the finite element method, the calculation error and the reason of stepped horn resonance frequency are consequently analyzed. Moreover, the affects of dimension on stepped horn resonance frequency is emphatically discussed. In addition, the correction method toward stepped horn in the design process is raised.3. According to the horn design theory and plate flexural vibration theory, theoretical calculation model of suspended tool is established, which is transferred from the mode that is consist of stepped horn and flexural vibration circle planar. Therefore, the relationship between dimension and resonance frequency is obtained.4. With the help of ANSYS, the dynamic analysis of suspended tool is proposed. Furthermore, the dimension of the tool is optimized and gain its displacement and stress distribution. Additional, the result of the vibration experiment indicates that the pitch circle radius of suspended tool is accord with the result of the finite element analysis.