Research On The Diffusion And Injection Characteristics Of Micro Pores In The Micro Delivery Drug Chip

Microfluidic chip is a new technology for controlling fluid at the microscale.Microfluidics offer advantages of large specific surface area,shorter diffusion distance,and laminar flow field in reaction systems to improve mass transfer efficiency,reduce reagent consumption and drug transport.Research on mass transfer method on microfluidic chips including porous diffusion and cellular injection was carried out respectively.Combined with the establishment of mathematical model,The characteristics of mass transfer and its function of the drug delivery were simulated by numerical simulation.In this paper,the mathematical model of the drug delivery is established for the micro-pore diffusion and injection.For the diffusion of micro pores,the structure of the three layer of the/PDMS chip/PCTE/PDMS chip is designed.The mass transfer model of drug delivery was studied by the diffusion of micro pores,based on the basic theory of fluid mechanics and the theory of mass transfer in the microscale,the total mass transfer resistance and the thickness of the diffusion layer in the process of liquid mass transfer are deduced and calculated,the mathematical model of the diffusion of micro pores is established.The concentration distribution of drug solution after the diffusion of drug solution was obtained by using MATLAB software,the influence of pore size,porosity and distribution of the pore size on the diffusion and mass transfer is discussed.For the micro hole injection,the thin wall micro hole nozzle model of PDMS micro channel is established,based on the theory of micro jet,the optimal frequency of the jet velocity and the fracture of the jet is deduced,and the theoretical basis is provided for setting the simulation parameters.The numerical simulation of the micro hole diffusion and the injection process is carried out with the flow field analysis software.By setting the parameters of the micro pore size,the pore size distribution and the flow velocity of the liquid inlet,the pressure field of the micro pore is calculated,and the change of solute concentration in micro pores is analyzed.The process of micro droplets formation in micro channels is simulated,the relationship between the frequency of the droplet and the input parameters of the droplet is determined by the study of the parameters of the pore size,the inlet velocity and the contact angle.Through the simulation of the drug delivery process,the flow pressure function of the two methods of diffusion and injection is quantitatively analyzed,and the characteristics of the drug delivery efficiency are also analyzed,the advantages and limitations of each are discussed,and the structure design and parameters selection of the chip are provided and provided some theoretical models.The accuracy and controllability of the microfluidic delivery mechanism are further realized,and the application of mass transfer theory is extended to the micro scale.