Rapid Prototyping Of Microfluidic Devices By Combining Wax Substrate And CNC Micromilling

Microfluidic devices,as a new biochemical analysis platform,have the advantages of fast analysis speed,less reagent consumption,easy integration and automation.In recent years,microfluidic devices have received wide attention and have been applied in the fields of biology,medicine and chemistry.However,its widespread applications are limited due to time-consuming fabrication process and high development costs.Therefore,there is an urgent demand for the development of simple and low-cost method to microfluidic devices with minimal time expenditure.In this thesis,to meet the demand for prototype microfluidic devices during the scientific research in common laboratories and the development of new analytical devices in mini enterprises,based on the previous work in our research group,a novel strategy for rapidly and cheaply fabricating microfluidic devices was presented,which used microcrystalline wax as substrate,and combined CNC micromilling technique and replica moulding method to fabricate PDMS-based microfluidic devices.The main contents of this thesis include:(1)A method for fabricating flat wax substrate with smooth surface was developed.By confining molten paraffin in a glass frame and combining with “film-wax-glass” sandwich structure,a high yield production of smooth wax substrate was realized,which pave the way for the development of follow-up process.(2)The effects of different fabrication parameters and conditions on the microstructure were systematically studied,achieving a set of optimal parameters and conditions.In addititon,to address the problem of the surface roughness of the microstructures prepared by micromilling,a gas-blowing-assisted PDMS coating was proposed to improve the surface quality of the fabricated microstructures.By coating a thin layer of PDMS on the surface of the fabricated microstructures,the rough structures of the fabricated surface are shielded,achieving the optical quality surfaces,which provides guarantee for the fabrication of high quality microfluidic devices.(3)Several typical microfluidic devices have been fabricated quickly and conveniently by using the developed method.The fabricated devices demonstrate the advantages of CNC micromilling for the fabrication of three-dimensional structures.The results also confirm that this method combining wax substrate and CNC micromilling offers the advantages of low-cost,rapidness and multifunctional integration for the fabrication of microfluidic devices.It will promote the extensive research and application of microfluidic technology.In this paper,a rapid and low-cost fabrication process of microfluidic devices based on wax substrate and CNC micromilling is established.Compared to the traditional micromilling fabrication,it can fabricate more fine microstructures and has wider applicability.It provides an effective solution for rapid,efficient and low-cost fabrication of prototype microfluidic devices,and will promote the wider research and application of microfluidic technology.