Fast-mixing And Spraying Microfluidic Chip For Cryo-EM

The structure of biological macromolecules is the embodiment of basic laws in life sciences.It is the cornerstone for people to study the origin and future direction of life.It is the basis for our deep understanding of life activities from the microstructure.It freezes many scientific fields such as biomedicine and pharmaceutical research.In recent years,electron microscope technology has achieved remarkable results in terms of both software and hardware,leapfrog development,and even a wider range of scientific research fields,helping researchers to analyze the structure of biological macromolecules close to the level of atomic resolution.Biology,with the advancement of image acquisition and data processing technology,the analysis and imaging efficiency of biological macromolecular structures have also improved significantly.However,the traditional sample preparation method is inefficient,time-consuming and shrinking,and it is difficult to sample the intermediate products of the biological macromolecule reaction process in time.The further development of sintered cryo-electron microscopy in the field of time resolution.This study utilized the advantages of microfluidic chips in the field of microscale biochemical analysis,designed and manufactured an integrated micro-mixing and spraying function to shorten the preparation time of cryo-electron microscopy samples,improve efficiency,and eliminate the interference of manual operation uncertainty.The microfluidic chip verifies and analyzes its applicability and performance and summarizes the design ideas and empirical rules.For the structural design of the microchip,based on reviewing the contributions and experience of the predecessors,a variety of microfluidic phenomena such as secondary flow is comprehensively utilized,and a novel micro-hybrid structure is proposed,which is numerically simulated and three typical models.The mixed functional structure was compared and analyzed,and the design ideas of the high-performance micro-hybrid structure were summarized.The three main processes of the micro-spray were analyzed by numerical simulation.It was found that the micro-scale spray process is different from the traditional macro-atomizer,and the micro-spray is discussed.Mechanism and design rules.In the experimental research,the selection and manufacture of microchips were studied,and the flow rate of inlet solution(0.001 ?L/s-0.1 ?L/s)and viscosity[0.001kg/(N·m)-0.799kg/(N·m)]are controlled to observe the mixing effect and spray performance under different conditions,and verify the correctness of numerical simulation and the advantages,disadvantages and feasibility of micro-mixed spray chips using PDMS materials.The micro-mixed spray chip designed and manufactured in this study is characterized in that it can achieve rapid mixing of high viscosity and lower viscosity solutions in a wide range of liquid flow rates without external energy,and the uniform mixing time is controlled below 0.1ms.Faster rapid mixing performance;with the aid of the gas jet,the uniformly mixed liquid is blown out at the outlet,and the droplet diameter is controlled below 20 ?m,which can achieve a better liquid atomization transmission process.In the application of biochemical analysis,the controllability of the reaction process is enhanced,and the time of preparation and preparation of biological samples is shortened.The application in cryo-electron microscopy can improve the efficiency of sample preparation and promote its development in time-resolved research.The application prospects that people expect.In addition,through numerical simulation and experimental analysis of the mixed spray process under different conditions,it is found that the atomization effect is basically not affected by the viscosity of the liquid during the spray process at the micro-scale;mainly due to the influence of the angle of the auxiliary jet,the larger the spray angle The better the atomization effect is;the relationship between the atomization effect and the airflow velocity is the same as that under the macroscopic one,and the atomization effect does not increase indefinitely as the airflow velocity increases.