Droplet Separation Method And Experimental Studies On Microfluidic Chip

Because in some areas increasingly wide application of micro-droplets, so the dropletgeneration technology and its application in microfluidic technology approach has attracted moreand more attention. Micro-droplets production have a lot of factors, this thesis is based on theComsol simulation, discusses several factors to the sizes of generate micro-droplet, andanalyzed by experiments in summary, and compared with simulation.First, this paper introduces microfluidic chip status and development prospects as well asthe application and development of micro-droplets, there are some basic microfluidicmultiphase flow theory and microscale droplet formation theory, to be a theoretical guidance forsoftware simulation, and provide a theoretical basis for microdroplets experiments.Secondly, through Comsol software simulate micro droplets formed process,obtain theresult that microchannel width to depth ratio is set to1, the fluid velocity increases the slowest,the fluid flow rate is the fastest, generate droplets easily; determine the range of dropletgeneration; summarize the influence to the droplet size through continuous phase and discretephase flow rate and the total flow rate when the flow rate ratio is constant; when the dispersedphase rate is fixed, the continuous phase flow rate is increased, the size of the droplet becomessmaller; when the continuous phase flow rate is constant, the dispersed phase velocity isincreased, the droplet size is gradually increased, but to a certain extent also tends to decreased;when the two-phase flow rate ratio is constant, the total flow rate increases, the droplet size isgradually reduced.Finally, design the micro-channel structure having a shut cross structure; manufacture thecircular channel chip with PDMS material by actin law; manufacture the rectangular channelchip with glass material by etching; complete the development and design of the microfluidicchip injector; through the experiment of micro-droplets generation by a cross-shapedmicrofluidic chip, summarize droplet generation region, generalize the influence to the size ofthe droplets by the flow rate of the continuous phase and the dispersed phase, the total flow ratewhen the constant flow rate ratio, and consistent with the simulation results basically.In summary, based on cross-type microfluidic chip, can effectively generate micro-dropletson demand, and can achieve the intended purpose, but there is still insufficient:①cross-shapedstructure has shut structure, the outlet channel use dilated microchannel and process simple;②Provide the necessary external pressure very small when the micro-droplets generation;③effective generate nanoliter or even leather upgrade or fly upgrade microdroplets;④the uniform size and stability of the micro-droplets generation;⑤failure to discuss the impact of droplet sizefrom the fluid viscosity and temperature, etc.