Based On Microfluidic Chip Droplet Generation And Research On Droplet Splitting

In In recent years,the outbreak and spread of the new crown epidemic in my country has seriously endangered the lives of the people.In the stage of normalized epidemic prevention and control,nucleic acid testing is an important means to prevent the epidemic.As a key technology for nucleic acid detection,microfluidic-related technology has become a hot research topic.In order to further amplify the advantages of microfluidic chips in terms of high efficiency,abundance and low cost,microdroplet preparation technology has become the focus of research in the field of microfluidics,and in-depth research on droplet generation and droplet splitting not only enriches and expands The microdroplet preparation technology also has important medical and engineering application value.This paper takes the microfluidic PDMS chip as the research object,and uses the simulation analysis software to study the droplet formation and droplet splitting movement.Finally,experiments are used to verify the feasibility and correctness of the simulation analysis,and provide a technical reference for the large-dose and high-speed preparation of microdroplets.Its main contents are as follows:(1)The influence of the physical parameters of the microfluidic chip on the formation and splitting of droplets was discussed.In the study of droplet formation movement,it was found that:(1)the increase of the continuous phase flow rate or the increase of the continuous phase viscosity will reduce the diameter of the formed droplet,and the frequency of the formation of the droplet will increase accordingly;(2)two The increase of the interfacial tension will increase the diameter of the droplets,and the frequency of droplets will decrease.In the study of droplet splitting motion,it was found that:(1)The increase of the flow velocity of the main channel or the increase of the viscosity of the continuous phase will reduce the splitting period of the parent droplet,and the diameter-width ratio of the daughter droplet is a certain value.;(2)The increase of the interfacial tension between the two phases increases the splitting period of the parent droplet,and the diameter-width ratio of its daughter droplets is a certain value.(2)The influence of the structural parameters of the microfluidic chip on the splitting motion of the droplets is discussed.Taking the symmetric Y-shaped microfluidic chip and the asymmetric Y-shaped microfluidic chip as the research objects respectively,it was found that:(1)When using the symmetric Y-shaped microfluidic chip,with the increase of the ratio of the blocking length at the bifurcation to the width of the main channel Or the increase of the Y-shaped bifurcation angle will reduce the splitting period of the parent droplet,and the diameter-to-width ratio of the daughter droplet is constant;(2)When an asymmetric Y-shaped microfluidic chip is used,the bifurcation is blocked.The increase of the ratio of the length to the width of the main channel will increase the splitting period of the parent droplet,while the diameterwidth ratio of the daughter droplet is constant.is reduced,and the aspect ratio of the sub-droplets is a certain value.(3)An experimental platform was built,and the simulation analysis results of droplet generation movement and droplet splitting movement were experimentally verified.The results showed that the experimental results were in good agreement with the simulation results,which verified the accuracy and reliability of the simulation analysis results.sex.Through simulation analysis and experimental verification,it is shown that the use of Fluent fluid simulation analysis software can play a good role in analyzing and predicting the actual microfluidic droplet generation and droplet splitting movement process,and has a good effect on the design of microfluidic chips.reference.