Study On The Convection Diffusion Characteristics Of Cell Drug Delivery Microchip

Microfluidic chip technology is based on the mechanism of micro-scale fluid transport,and can realize the manipulation of flow,the capture chemical analysis,cell culture,drug screening,cells dosing and other functions.Microfluidic chip also has many advantages such as high integration level,small volume,low cost and multi-function.Thus,the application of microfluidic chip to the drug system and micro scale is widely promoted.In this paper,my work is based on fluid dynamics first,then flow diffusion theory.Combined with the actual size of the diffusion of microchips and factual hypothesis,the simplified convection diffusion mathematical-physical model of microfluidic cavity is established.Calculations and derivation efforts are both implemented to work out the analytical solution of mathematical physical equation.All these theories lay the foundation of numerical simulation,flow field analysis and the theoretical basis for the analysis of the microfluidic chip.Meanwhile,incorporated with convective diffusion and porous media dispersion theory,software like COMSOL Multi-physics is applied to simulate convection diffusion behavior in microchip.By changing the parameters such as flow velocity and the distance between the droplets,the research of diffusion concentration distribution,the change of the concentration in each part as well as single droplet,double liquid droplet in convection process are investigated.Results show that a single droplet can lead the maximum convection velocity of 0.001 m/s under medication-on condition.Flow velocity in micro channel peaks in the distance of 25?m-30?m from the bottom.In case of double liquid droplet,optimal droplet spacing is 55 ?m to satisfy the micro trap concentration under maximum convection velocity.Given the optimal droplet spacing,different convection velocity impact the micro trap concentration to a range of value.It is found that convection velocity of 0.05m/s make the perfect medication-on condition.To make these work results more of factual value,experimental platform of convection diffusion is established.The dispersion of the tracer particles,concentration distribution in convection process are investigated simultaneously.Experimental results and numerical results are compared,showing that a comparatively identical character.Velocity field in this microchip is also analyzed,actual velocity ranges from 0.023m/s to 0.134m/s corresponding to the theoretical result of 0.1 m/s.In conclusion,both theoretical and experimental methods are implemented to investigate the convection-diffusion process in microchip.Concentration distribution results of different micro-traps under series of conditions are achieved.All these works give support in optimizing microchip structure and accurately controlling in drug administration,which make this technology more factual and controllable used.