Research On Key Technology Of A Spiral Flow-through PCR Device With Variable Cross Section

In this paper,by analyzing the characteristics of polymerase chain reaction and microfluidic chip technology,combined with the structural characteristics of the existing PCR analyzers,this paper designs a spiral continuous flow with variable advantages and variable cross section Microfluidic PCR chip.The relevant parameters of the chip flow path are simulated and the preparation of the chip is completed.Finally,the performance of the chip was tested by PCR.The main work is as follows:1,A spiral continuous flow variable cross section microfluidic PCR chip was designed.According to the characteristics of microfluidic chip technology and combined with the principle of PCR amplification,a microfluidic chip with variable continuous flow cross section was designed.The chip was composed of two parts: substrate and cover sheet.Inside and outside of the road was spiral arrangement,the depth of channel remains unchanged,the width of channel gradually becomes smaller,the size of the chip is micron level.The temperature distributions of PDMS-PDMS and PDMS-glass were compared by simulation,and the thermal radiation effect of PDMS-PDMS was smaller than that of PDMS-PDMS.According to the principle of equal volume of fluid flow in each circle,the change value of section is deduced.2,The relevant parameters of variable flow microfluidic PCR chip flow path are analyzed by COMSOL software.The velocity of the fluid in the microchannel is simulated by establishing an equivalent model.The results show that the heat transfer rate at the microscale is very fast and the time required is in milliseconds.At the same time,the pressure and velocity simulation of the flow channel designed in this paper are carried out.The changes of pressure and velocity corresponding to the change of temperature,initial velocity and cross-section of flow channel are mainly analyzed.The simulation results show that the microfluid flow and pressure in the ideal state are mainly related to the velocity,the influence of temperature is small,and the velocity is mainly Flow cross-section related.3,The preparation technology and reaction system of PCR chip were studied.The physical and chemical characteristics of PDMS polymer were mainly analyzed.The preparation process of the microfluidic PDMS chip was studied.The preparation process of the PDMS chip mainly included the preparation of the silicon-cationic film,PDMS curing,surface modification and passivation of the PDMS flow channel and PDMS-PDMS Bond.The connection scheme of temperature control system,reaction chip part and reaction liquid injection system was completed,and the connection scheme of each component was optimized.The experimental parameters such as temperature control,reaction time and injection speed were analyzed and analyzed.4,The performance of microfluidic PCR chips has been tested,including flow performance and PCR amplification performance.And through the experimental test,obtained in 25?l system by adding 4?g PVP can be achieved PCR amplification,and finally achieved the completion of 30 amplification cycle with only 16.7min.