Design And Application Of Droplet Fusion Chip Based On Microfluidic Technology

The microfluidic chip is also called a chip laboratory,which integrates basic operation units such as sample preparation,separation,reaction,detection,cell culture,and sorting involved in the fields of chemistry and biology into a tiny chip.With the maturation of soft lithography processing technology in recent years,polydimethylsiloxane(PDMS)microfluidic chips have developed rapidly.The droplet is the basic volume unit that manipulates the sample on the microfluidic chip.The reaction in the droplet can be used in many applications,including particle formation,chemical synthesis,kinetics research,or for the synthesis of biomolecules.Droplet fusion is a basic tool for controlling microdroplets in microfluidic devices and their use as microreactors.Controlled polymerization of droplets is an important means of performing reactions within the droplets,as it allows for well-defined points in space and time Precisely mix reagents and fuse samples.This subject is dedicated to building a laboratory microfluidic chip experimental platform,designing and processing PDMS droplet fusion chips to achieve controlled fusion of droplets.The main research contents are as follows:1.Set up a microfluidic chip experimental platformThis project uses a laboratory-designed pneumatic pump as the sampling drive system,and controls the output pressure of the pneumatic pump to achieve precise control of the continuous phase and discrete phase flow rates.Use CAD drawing software to design the droplet fusion chip structure,and use the soft photolithography process to make PDMS droplet fusion chip.On the established microfluidic chip experiment platform,generate and control the fusion of droplets.Use software programming to analyze a large number of droplet fusion pictures,view the fusion effect,and continuously improve the fusion structure,and finally get a stable droplet fusion chip structure.2.Design and manufacture of droplet fusion chipAdopt the idea of modularization,the droplet fusion chip designed in this project includes droplet generation module,droplet intersection structure,droplet fusion structure and collection structure.Two droplet generation modules: to achieve precise control of the parameters such as the size and interval of droplets generated by controlling the flow rates of continuous and discrete phases.Droplet confluence module: control the ratio of droplets to converge through the size of the flow channel and the distance between droplets.Droplet fusion structure: by designing a special flow channel structure,the droplets are controlled to decelerate and collide here,thereby generating fusion.Collection structure: collect and analyze the fusion droplet information.This topic firstly conducted experiments on key parameters in droplet generation,and conducted detailed studies on the confluence angles of continuous phase and discrete phase,flow channel width,liquid flow rate,and other related influencing parameters.Control conditions.On the basis of droplet generation technology,this topic further studies droplet fusion related technologies.First,the ratio of two droplets is controlled to merge,and then a controlled proportional fusion of droplets is achieved at the fusion structure.Collect the image information of the droplet fusion,and analyze and process the droplet fusion image using Image J software to obtain the fusion success rate and realize the controllable and efficient fusion of the sample.