Design And Manufacture Of Microchemical Reaction Tracking Microsystem Based On Lamb Wave Acoustic Pressure Sensors

Microchemical reactor is a kind of micro chemical equipment that can control the process of chemical reaction by controlling the flow rate of chemical reaction,which can greatly shorten the reaction time,improve the reaction efficiency and be highly integrated.It can be integrated with the micro sensor chip.In recent years,it has received more and more attention.Tracking microchemical reactions plays an important role in the characterization of related parameters in the process of chemical reactions,such as chemical reaction rate,conversion rate,equilibrium constant,optimal temperature,etc.Some existing methods are not easy to integrate with microchemical reactors,are not suitable for microchemical reactions and cannot realize real-time on-line detection.In order to realize real-time online tracking of microchemical reactions generated by gaseous substances,a lamb wave acoustic pressure sensor based microchemical reaction microsystem was designed in this paper to track the progress of chemical reactions by detecting pressure changes.Pressure sensors based on acoustic resonators have the advantages of high sensitivity,linear output response and easy integration.This paper introduces the design and manufacture of aluminum nitride(ALN)lamb wave Micro Electro Mechanical System(MEMS)resonator,and its application in pressure detection,real-time monitoring of enzymatic reaction and real-time online flow rate monitoring integrated with polydimethylsiloxane(PDMS)thin membrane.This paper first introduces the overview of ALN lamb wave,including its working principle,lamb wave property,performance parameters and MEMS manufacturing process.Secondly,materials with excellent piezoelectric properties were used to develop micro pressure sensors that could quickly detect changes in pressure signals in a dynamic and short time with high resolution.The results obtained by COMSOL finite element simulation were basically consistent with the real experimental phenomena,which proved the feasibility of using lamb wave resonator(LWR)to detect changes in pressure.After that,ALN LWR pressure sensor was used to monitor the enzymatic reaction catalyzed by catalase to decompose hydrogen peroxide online in real time,and the enzymatic reaction constants₈)and6)₍(8(6)were calculated.Finally,by integrating PDMS with flow channel and LWR pressure sensor,a real-time online flow rate detection system based on LWR pressure sensor was built,which has high repeatability and sensitivity.