The Design,Fabrication And Application Of Microfluidic Chip Based On Near-field Melting Electrospinning

There are various kinds of the materials and fabrication methods of microchannel molds.The widely used materials of microchannel molds generally include silicon wafer,glass and other silica-based materials;maltose,photoresist,PMMA,PVA and other polymer materials;stainless steel microwire,PCB board,stainless steel block and other metal materials.The methods of microchannel mold fabricatione generally include lithography,microwire-molding,machining,3D printing,electroforming and so on.Near-field Electrospinning makes use of the stable stage of polymer solution or melt jet to obtain ordered micro&nano fibers.The patterned and ordered fibers obtained by Near-field Electrospinning can serve as microchannel mold with high resolution.The method requires simple machine,cheap materials and easy procedure with one step.The main work of this thesis:(1)CAD Graphic Direct Compensation method.The process of near-field melt electrospinning was introduced.The influencing factors of PCL jet morphonogy were investigated duiring Near-field Melt Electrospinning process at high heating temperature,and the motion of collector was analyzed.In view of the unprecise deposition in Near-field Melt Electrospinning,CAD Graphic Direct Compensation method was proposed to achieve precise deposition,and the optimal compensation length under various conditions was investigated.Finally,the PCL fiber with round cross-section was obtained by employing the semi cured PDMS as collector.(2)Multi-layer Near-field Electrospinning process and Minimum Spacing method.Under the high heating temperature for PCL,CAD graphics of double spirals and wavy microchannels were designed,and the influence factors of Near-field Electrospinning on the morphology of single-layer and multi-layer fibers were investigated.CAD graphics of double spirals and wavy microchannels were optimized,and the process parameters suitable for multi-layer Near-field Electrospinning were investigated.The Minimum Spacing design method was proposed for spiral CAD graphics to solve the CAD graphics design problems of multi-layer depostion of fibers and multiple inlets &outlets.Finally,the Minimum Spacing design method was introduced to obtain PCL fibers with variable diameters.(3)Design,fabrication and application of microfluidic chip.Based on the analysis of the previous continuous flow PCR microfluidic chip,a kind of continuous flow PCR microfluidic chip was designed,and a continuous flow PCR PDMS-glass hybrid microfluidic chip was fabricated by using CAD Graphic Direct Compensation and PDMS soft lithography.The PCR experiments of Staphylococcus Aureus were conducted on the continuous flow PCR microfluidic chip.Based on the analysis of the previous double spirals and wavy microfluidic chips,the double spirals and wavy microfluidic chips were designed and fabricated by multi-layer Near-field Electrospinning and PDMS soft lithography.