Study On The Fabrication Of Polymer Microfluidic Chip

Microfluidic chip is the microstructure integrated device for processing,detecting and outputting and it is the main platform of the microfluidic.Polymer chip is a good inexpensive materials to replace quartz,silicon and glass,and the types of polymers are numerous.Micromixer is an important branch of microfluidic chip,which has a wide application in the field of biochemical engineering.The micromixers can be roughly divided into active and passive micromixers.The study of the geometrical structure becomes more and more important due to the fact that the mixing of liquid solution does not rely on the external energy.With the rapid development of processing technology,the structure of its micro-channel is also varied.Therefore,we studied process parameters of CO₂-laser for polymers and the design,simulation,analysis and experimentation of micromixer.The main research work of this dissertation is summarized as follows:?1?CO₂-laser is used to cut the PMMA and PET sheets by melting and blowing away vaporized material for obtaining high-quality channels.The influence of four parameters such as laser power,scanning speed,channel length and processing times on the quality of polymer microchannel formation is studied by orthogonal experiment.?2?The working temperatures of the two polymer materials are determined by experiments.The thermal bonding parameters of four-layer PMMA microfluidic chip are studied,and the relationship between bonding temperature,pressure and time is obtained.In addition,the problem of microchannel dislocation and blockage between the upper and lower layers is solved.?3?The micromixers of diamond-like micropillar,F-shape,E-shape,SESM and FESM are designed.Linking artificial neural network?ANN?is used to optimize the diamond-like micropillar,and the mixing efficiency at the outlet is determined.Then,the fluid mixing behavior of F-shape,E-shape,SESM and FESM in microchannels is visualized by COMSOL Multiphysics.?4?The micromixers of F-shape,E-shape,SESM and FESM are fabricated by processing equipment,and the thermal bonding process is developed for eight-layer SESM.Finally,the mixing efficiency of four micromixers at different Reynolds numbers is obtained by mixing the characteristics of phenolphthalein and sodium hydroxide.In this paper,the effects of CO₂-laser processing parameters for the microchannel quality of polymer is studied.The temperature,pressure and time of thermal bonding parameters of multilayer PMMA chips is determined.The five micromixers are designed by the mixing mechanisms and evaluated their mixing properties by mixing experiment.