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The Research Of A Method Based On Localized Heating Leading To Self-Sealing To Form Polymer Microfluidic Channel

Posted on:2016-11-11Degree:MasterType:Thesis
Country:ChinaCandidate:S F WangFull Text:PDF
GTID:2298330467987040Subject:Fluid Machinery and Engineering
Abstract/Summary:PDF Full Text Request
The micro/nano fluidic channels are an important part of micro-fluidic chips. Since the characteristics that fluid flows in the microscale is different from in the macroscopic scale, it has many important applications. The choice of the appropriate micro/nano technology which can accurately efficiently fabricate micro/nano channel become a hot topic. In this paper, owing to the selection of a reasonable process, the PMMA groove micro structure is prepared on a glass substrate and the PMMA micro channel structure is fabricated by the method of localized heating.In the preparation of PMMA groove microstructure, first of all,wet etching technology is used to fabricate silicon groove microstructure template. Then the PUA groove microstructure is prepared on a PET substrate by UV nano-imprint lithography (UV-NIL). Finally PMMA groove microstructure is fabricated on a glass substrate by hot embossing nano-imprint lithography (HE-NIL). In the experiment, the operations and attentions of each process are discussed in detail. Furthermore the influence of various factors on the experimental results is illustrated. Based on the theory of adhesion,PUA groove template preparation process is analyzed in detail, the critical aspect ratio that PUA groove template can be successfully replicated is calculated. Finally PUA groove template with high aspect ratio is successfully replicated.In the sealing process of PMMA groove microstructure, a home-made simple device is used to heat the top locally, then the polymer PMMA at the top melt, flow downwards along the lateral wall as a result of the surface tension from the polymer melt and extrusion from the silicon wafer, eventually the capillary force and the atmospheric pressure come to balance and form micro-channels. In order to solve the heat transfer problems of the experiment, a semi-infinite object transient heat transfer model is established, thus reasonable relative velocity between the silicon wafer and the substrate can be obtained. If the changes in polymer volume after melting can be ignored, the geometric model can be used to control the size of micro-channel. In addition, the effect from the direction of relative movement between the silicon wafer and the substrate which is parallel or perpendicular to the direction of PMMA lines is discussed. These studies provide theoretical guidance for the experiment, which is likely to form a new method to prepare micro-channel.
Keywords/Search Tags:Micro-fluidic channel, Wet etching, UV-NIL, HE-NIL
PDF Full Text Request
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