【作者】 李瑞；

【导师】 马秀清； 余力；

【作者基本信息】 北京化工大学 ， 机械工程（专业学位）， 2020， 硕士

【摘要】 微流控技术是在几百微米甚至更小的通道中对流体进行操纵完成各种实验的技术。它能做到运用微量的样品或试剂进行具有高分辨率的分离和检测。而微流控芯片是实现微流控技术的重要装置。微流控芯片的加工材料、加工方法和降低通道内的粗糙度无疑是微流控技术发展中最关键的问题。而高分子材料具有来源广、品种多、易加工等优势受到了微流控芯片研究者的重视。同时其加工方法微注塑成型因为可以实现批量、连续生产,也引起微流控芯片制造者的关注。本文通过研究微流控芯片的注塑加工工艺,采用正交分析的方法确定熔体温度、模具温度、注射速度、保压压力对微流控芯片注塑成型过程中的影响顺序和最优注塑工艺,并取用在最优注塑工艺下成型的微流控芯片的进行液体混合实验和液滴成型实验。本文的主要研究内容及结论如下:(1)根据注塑模具加工精度和液滴生成装置以及液体混合装置的特点,确定液滴生成装置通道截面的尺寸为500μm×500μm,液体混合装置通道截面的尺寸为400μm×400μm。运用专业软件COMSOL进行了液体混合和液滴生成的仿真,由仿真结果证实当液滴生成装置的通道截面为500μm×500μm,分散相流体的速度为连续相流体的1/2时,微通道内形成稳定的液滴。当液体混合装置的通道截面设计为400μm×400μm,液体的混合流速为5μL/min时,液体混合效果良好。根据仿真结果设计了微流控芯片。(2)针对注塑工艺特点和微流控芯片的结构进行了模具设计。并利用Moldflow软件对微流控芯片的充模过程进行了模拟分析,结果表明设计的模具能够满足微流控芯片的成型加工,同时也说明浇注系统和加热系统是合理的。(3)利用正交实验对微流控芯片的注塑成型加工进行实验研究,并以微流控芯片的单流道测试装置的开口宽度、槽深、槽底宽度为指标,通过实验结果分析不同的注塑工艺对微流控芯片中单流道测试装置注塑成型的影响,得出微流控芯片在可选范围内的最优注塑工艺参数。并与CO2激光加工成型的微流控芯片进行对比分析,得出采用注塑加工微流控芯片更有优势。(4)利用在最优注塑工艺成型后的微流控芯片进行液体混合实验和液滴生成实验,验证注塑加工条件下微流控芯片的功能性。并与CO2激光加工的微通道进行对比,发现采用注塑加工生产的微流控芯片能够更好的满足微流控实验的要求。更多还原

【Abstract】 Micro-fluidic technology is a technology that manipulates fluids in flow channels of hundreds of microns or smaller to complete various experiments.It can achieve high-resolution separation and detection using trace samples or reagents.The micro-fluidic chip is an important device to realize micro-fluidic technology.The processing materials,processing methods and roughness in the flow channel of the micro-fluidic chip are undoubtedly the most critical issues in the development of micro-fluidic technology.The advantages of polymer materials,such as wide source,variety and easy processing,have been paid attention by micro-fluidic chip researchers.At the same time,its processing method,micro-injection molding,has also attracted the attention of micro-fluidic chip manufacturers because it can achieve continuous production.In this paper,by studying the injection process of the micro-fluidic chip,the orthogonal analysis method was used to analyze influence of the melt temperature,mold temperature,injection speed,and holding pressure on the micro-fluidic chip injection molding process to determine the best injection process.At the same time,the micro-fluidic chips were formed under the optimal injection molding process,and they were used for liquid mixing experiment and droplet forming experiment.There are four main contents and conclusions of this paper as follows:(1)In the light of the processing accuracy of the injection mold and the characteristics of the droplet generation device and the liquid mixing device,the size of the flow path of the droplet generation device was determined to be 500μm × 500μm,and the flow size of the liquid mixing device was 400μm×400μm.Using professional software COMSOL,the simulation of liquid mixing and droplet generation was carried out.The simulation results confirmed that when the cross section of the flowing path of the droplet generation device was 500μm × 500μm and the velocity of the dispersed phase fluid was 1/2 of that of the continuous phase fluid,the micro-flow stable droplets were formed in the channel.When the cross section of the flow channel of the solution mixing device was designed to be 400μm× 400μm and the liquid mixing velocity is 5μL/min,the liquid mixing effect was good.The micro-fluidic chip was designed according to the simulation results.(2)The mold design was carried out according to the characteristics of the injection molding process and the structure of the micro-fluidic chip.The mold filling process of the micro-fluidic chip was simulated and analyzed using Moldflow software.The results show that the designed mold can meet the molding process of the micro-fluidic chip,and it also shows that the pouring system and the heating system were reasonable.(3)Orthogonal experiments were used to conduct an experimental which studys on the injection molding of the micro-fluidic chip.By using the opening width,groove depth,and bottom width of the single-channel test device of the micro-fluidic chip as indicators,there was analysis the influence of the injection molding process on the injection molding of the single-channel test device in the micro-fluidic chip,and there was obtaine the best injection molding process parameters of the micro-fluidic chip in the selectable range.Compared with the micro-fluidic chip formed by CO2 laser processing,it is concluded that it was more advantageous to use injection molding to process the micro-fluidic chip.(4)Useing the micro-fluidic chip formed in the best injection molding process to conduct liquid mixing experiments and droplet generation experiments to verify the functionality of the micro-fluidic chip under injection processing conditions.Compared with the micro-channel processed by CO2 laser,it was found that the micro-fluidic chip produced by injection molding can better meet the requirements of the micro-fluidic experiment.更多还原