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Investigations On Flexible Manipulation Methods For Micro/Nano Scale Objects

Posted on:2010-08-12Degree:DoctorType:Dissertation
Country:ChinaCandidate:Y YangFull Text:PDF
GTID:1101360278960439Subject:Refrigeration and Cryogenic Engineering
Abstract/Summary:PDF Full Text Request
During the exploration of the microcosms, the heavy demand for the diversification of micro manipulation remains the same as its counterpart macro-scale tasks. As a result, developing micro/nano scale manipulation device which is low in cost, high in reliability and precision has become one of the major targets within the MEMS area. Aiming to tackle such tough issues, the present thesis attributed the micro manipulation into two types: the micro manipulation on the object at solid state and that at liquid phase. Several new flexible methods for manipulating micro/nano scale objects were proposed:Aiming to the micro object at solid state, this thesis is dedicated to investigate a new kind of manipulation tool named as freeze tweezer. Numerical simulation is performed to understand its typical implementation mechanisms and several new working principles are proposed to improve its performances. Through the systematical analysis and experiments, it is demonstrated that the convective cooling enabled freeze tweezer could take on a quite excellent performance and adaptability. As a significant extension, the feasibility of the freeze tweezer with such principle in nano scale is illuminated via the theoretical heat transfer evaluation in free molecular flow. In addition, numerical simulation has also been carried out to demonstrate the radiative cooling enabled freeze nano tweezer.For the manipulation devices of the micro object at liquid state, this thesis proposed new working principles respectively for three micro devices. Aiming at the ice valve which was developed to close or open the micro/nano channel by freeze/thawing the working fluid inside, its typical implementation behaviors are numerically simulated; an alternative strategy for the controlling of the micro channel array via only a single ice valve is developed and a non-contact monitoring way for monitoring the ice valve array based on the far-infrared thermal imaging system is established. For the micro flow driving, this thesis presented a low cost micro pump for lab on chip through flexibly utilizing the wetting mechanism between the dry porous material and liquid. The working performance and several factors on the running state of the wetting pump have been proposed and evaluated. Further, based on the two-phase flow theory, this thesis established theoretical hydrodynamics model to characterize the micromixing pattern enabled by the time-interleaved segmentation feeding of micro fluid and put forward effective program to further improve the mixing efficiency. And the far-infrared thermal imaging system was also adopted to detect and map the surface temperature distribution of a micro mixture.In summary, the series of flexible manipulation methods for micro/nano scale objects as established in this thesis are expected to play an important role in micro/nano technology.
Keywords/Search Tags:Micro-electro-mechanical systems (MEMS), micro/nano scale manipulation, the micro/nano freeze tweezers, the micro ice valves, the micro wetting pump, the micro mixture based on Taylor dispersion, far-infrared thermal image system
PDF Full Text Request
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