Research On Mixing Characteristics Of Piezoelectric Micro Mixer With Sharp-Edge Microstructure And Its Driving System

In recent years,acoustofluidics based on sharp-edge structure has become one of the research hotspots and focuses in the field of acoustofluidics,and important achievements have been made in material synthesis,cell lysis,cell manipulation,sputum liquefaction,stool liquefaction,micromixing and chemical concentration signal generator,etc..The piezoelectric micro mixer with sharp-edge microstructure is one of the core contents of acoustomicrofluidics based on sharp-edge microstructure.In the research of piezoelectric micro mixer with sharp-edge microstructure,sometimes it is necessary to deal with toxic or dangerous chemical,biological and medical samples,or strictly ensure sterile environment,so as to minimize the contact operation of personnel to avoid danger and experimental pollution.However,at present,the driving system of piezoelectric micromixer with sharp-edge microstructure mainly uses independent special instruments and special circuits,which often takes a lot of time and energy in practical use,and takes manual way to carry out complex debugging and configuration of equipment parameters.When more experimental parameters need to be studied,the efficiency of the whole system is low;Generally,it is difficult to monitor and control the running state,parameters and results of the system in real time in this system.Especially for some researches with relatively long running time and many experimental parameters,the remote system which can monitor and control the experimental system remotely is needed to improve the efficiency of the whole system.Apiezoelectric micro mixer remote driving system based on sharp-edge microstructure is of great significance to solve the above problems.In view of the shortcomings in the research on mixing principle of the micro mixer with sharp-edge microstructure,the influence of the two energy transmission paths of acoustic radiation and elastic bending wave on the acoustic streaming of the micro mixer with sharp-edge microstructure was studied,and the energy source of the acoustic streaming generated by the micro mixer with sharp-edge microstructure was determined as the elastic bending wave of the bottom plate,after considering the propagation characteristics of elastic wave.Based on the elastic wave theory,the influence of different direction loads on the sharp-edge microstructure was analyzed,and the reasonable load form on the sharp-edge microstructure boundary was determined;The mathematical models of acoustic streaming principle and micromixing principle based on the basic hydrodynamics theory were established,and the multi physical field coupling simulation analysis was carried out.The influence of different flow rate,different driving voltage and different semi sharp angle microstructure on micromixing effect was studied.High accuracy evaluation of mixing effect is of great significance to the performance evaluation of micro mixer.Aiming at the problem that the existing mixing evaluation indexes were inconsistent with the actual mixing physical process,a high accuracy evaluation index and method based on image processing were established,which can accurately described the mixing physical process and this method takes into account the mean value and discrete information of image brightness;A method was established to compare and analyze the performance of various mixed indexes,and the reliability and repeated calculation accuracy of the performance of various mixed indexes were compared and analyzed.The results showed that the established mixing evaluation index could more accurately describe the physical process of the actual mixing,and the calculation results using the established mixing evaluation index had higher repeated calculation accuracy,and the description of the mixing process had higher accuracy.Owing to the current sharp-edge microstructure piezoelectric micro mixer driving system is mainly composed of independent special instruments and special circuits,it is difficult to form a highly integrated and miniaturized system,and it is not conducive to further automation and intelligence,and it is difficult to implement remote control.A single MOSFET tube digital broadband power amplifier structure suitable for low frequency piezoelectric transducer was established.The structure,working principle and performance test of the single MOSFET tube digital broadband power amplifier circuit were studied in detail.The design theory of the single-tube digital broadband power amplifier circuit was established,and the time-domain dynamic performance of this single-tube digital broadband power amplifier circuit is analyzed.A large number of experimental tests had been carried out using the built micro-mixing experimental system based on the remote driving system of the piezoelectric micro mixer with sharp-edge microstructures,and the experimental results were consistent with the results of the simulation analysis based on the design theory.In order to study the acoustic microfluidic research applicable to the treatment of toxic or dangerous chemical,biological and medical samples,and the need to strictly ensure the sterile environment,as well as the remote driving system of sharp-edge micro structure piezoelectric micro mixer in practical situations such as minimizing personnel contact operation,and aiming at the problems existing in the privacy information security and information sharing of the traditional remote system,and combining with the characteristics of the sharp-edge microstructure micromixing system,a piezoelectric micro mixer remote driving system based on sharp-edge microstructure structure was established,Based on the user perspective of remote services,user privacy information protection strategy and information sharing strategy suitable for a piezoelectric micro mixer remote driving system based on sharp-edge microstructure were analyzed and designed.A micromixing experimental system of piezoelectric micro mixer remote driving system based on sharp-edge microstructure was built,and experimental results were consistent with the simulation results in the theoretical analysis results.