Research On Key Technologies Of Noncontact Manipulation For Micro-Components Based On Ultrasonic Radiation Force Field

The Micro Electro-Mechanical System (MEMS), as a kind of high technology which helps people to understand and change the microscopic world, always possesses intensive demand to effectively manipulate micro-components with micro to nano meters in its development history of 30 years, because of the challenges due to the dimension miniaturization of research objectives, the three-dimensional manufacture with high depth-to-width ratio and the diversity of manufacture process & material. Especially, as the quick development of MEMS from the manufacturing of elemental parts to the integrated systems, the micromanipulation technology becomes even more important and urgent. Hence, exploring new theories and mechanisms to develop this technology is now the most basic and key topic in MEMS area.Considering the characteristics of MEMS, a kind of nondestructive, noncontact and remote manipulation technology should be the main trend in the current research and development. Hence, the manipulation technology based on ultrasonic radiation force field represents the direction of development. However, the theoretic research of this technology is still limited to the calculation of the radiation force on vibrating micro sphere at balance position, and its application is mainly on seizing, suspending and picking of biological tissue and cells. The research on theories and applications oriented to the characteristics of manipulation of micro-components and assembly of MEMS is seldom carried out.Therefore, the key technologies of noncontact manipulation for micro-components based on ultrasonic radiation force field were studied in this dissertation, which is supported by National Natural Science Foundation Program "Research on remote manipulation technology for micro-components based on controllable 3D ultrasonic radiation force field (No.50375144)", National High Technology Research and Development Program " Research on Key technologies of 3D tele-manipulation for micro and nano components based on ultrasonic radiation force (No. 2006AA04Z329)" and Key Project of Natural Science Foundation of Zhejiang Province "Research on theory and application of automatic 3D micro-assembly technology based on acoustic manipulation (No. Z1110393)". According to the characteristics of MEMS, by theoretical analysis and experimental study on the ultrasonic radiation force and torque of free-moving micro-components with complicated shape, the technology of spatial ultrasonic radiation force field synthesis was established to realize the precise control of ultrasonic radiation force and torque. This new technology can be applied in manipulation of micro-components and integrative assembly of MEMS, and can provide a general solution with self-owned intellectual property rights for the researches and productions of MEMS. The detailed contents and innovative points of this dissertation as below:In chapter one, by discussing the role and status of micromanipulation technology in MEMS, high-tech industries and the development of national economy, the significance to conduct the research on micromanipulation technology was described. The research status of the micromanipulation technology based on ultrasonic radiation force field was systematically summarized, its problems were observed and the research direction was pointed out.In chapter two, a universal scattering theory suitable for irregular Rayleigh scatterers in arbitrary sound fields was established to break out the limitation of the traditional theory that the incident sound field must be axisymmetric with respect to the scatterer. Besides, the theory was extended to the resonance scattering area by applying the T matrix method. The key basic problem in calculating ultrasonic radiation force and torque was solved.In chapter three, by applying the conservation law of entire momentum and angular momentum of sound intermediate and scatterer, a general framework for ultrasonic radiation force and torque was established. Then, the calculation of ultrasonic radiation force and torque on Rayleigh and resonant scatterers with irregular shape in arbitrary sound fields was realized to provide the theoretic foundation for the effective control of acoustic manipulation power source.In chapter four, in order to overcome the disadvantages of traditional ultrasonic field synthesizing methods that the sound source must be placed on the control boundary or the acoustic pressure can only be controlled point by point, a technology to synthesize ultrasonic field based on mode matching and inverse filtering was proposed, and the precise synthesis of ultrasonic fields in local area was also achieved by utilizing the attenuation property of Bessel function and inverse boundary element method. Meanwhile, in order to get the forward propagation operator, a new algorithm for sound field separation was raised by taking into consideration of the obstacle's disturbance in none-free space. This part of research provides the key technological guarantee for the controllable, precise and flexible manipulation of micro-components.In chapter five, according to different manipulation demands, the research on the synthesis and the adjustment of ultrasonic fields were carried out. Firstly, by adjusting the relative phase of plane waves, the positions of the acoustic potential wells were controlled to drive the micro-components to move along the desired route in wide range. Secondly, by utilizing the orbit angle moment of Laguerre-Gauss wave, the ultrasonic field is synthesized to endow the manipulation ability to trap and rotate the micro-components simultaneously through the interference of a Laguerre-Gauss wave with a plane wave of the same frequency but an opposite direction. Lastly, a strategy to pick up micro-components on a solid wall was raised, by synthesizing acoustic field using two symenetrically arranged incident plane waves.In chapter six, on the basis of completing the development of the multi-channel ultrasonic signal generator, ultrasonic annular array, ultrasonic field testing and microscopic imaging modular, an experiment platform for the synthesis and application of ultrasonic radiation force field was developed to satisfy the requirement of controllable synthesis of spatial acoustic fields and the application of micromanipulation. The noncontact manipulation experiments based on ultrasonic radiation force field were conducted by using above experiment platform. The results demonstrated the feasibility and effectiveness of the ultrasonic manipulation technology proposed in this dissertation and revealed its advantages including wide application range, high manipulation accuracy and suitability for manipulating micro-components.In chapter seven, the research results and the innovative points of this dissertation were summarized, and the future research works were also forecast.