Research On Design And Process Of Piezoelectric MEMS Pressure Sensor

Piezoelectric MEMS pressure sensors are widely used in Micro Devices,while the sensitive material is the key to the sensor technology.Therefore the main content of this paper is the piezoelectric MEMS pressure sensor in MEMS,PZT and BiFeO₃ with piezoelectric properties as sensitive material,PZT piezoelectric thin films were prepared by sol-gel method and spin coating technique,electrospinning technology was used to prepare BiFeO₃ nanofibers,and combined with silicon wafers,fabrication of Micro processing technology such as photolithography,magnetron sputtering and dry etching.A piezoelectric MEMS pressure sensor based on PZT piezoelectric film and BiFeO₃ nanofibers was obtained.Finally,design and build a set of pressure sensor test platform,carried on the preliminary performance test experiment,it provides theoretical basis and experimental basis for the application of multiferroic materials on Micro Devices.First,based on the parallel interdigital electrode structure,three kinds of pressure sensors with different structures are designed,MEMS pressure sensor based on PZT piezoelectric thin film?MEMS pressure sensor with elastic membrane cavity and BiFeO₃ nanofiber?MEMS pressure sensor based on BiFeO₃ nanofiber with no elastic cavity,for the structure of an elastic membrane cavity,use the PDMS film instead of the elastic membrane,and then the characteristics of three different types of sensors are analyzed and compared.Secondly,research the Micro processing technology and electrospinning technology.For Micro processing technology,redesign the process flow of three kinds of MEMS pressure sensor,optimization of experimental parameters and methods.PZT thin films were prepared by sol-gel method and spin coating method,elastic film cavity obtained by dry etching,preparation of PDMS films by spin coating process.For electrospinning technology,optimization of propulsion speed,electric field strength,plate spacing,receiving distance and other experimental parameters,parallel BiFeO₃ nanofibers were prepared on the electrode,the XRD and SEM characterization of annealed nanofibers were analyzed.Last,Design test system and build pressure sensor test platform,the test system mainly includes the vacuum device,the digital differential pressure gauge,the test circuit and so on,the preliminary performance test of the pressure sensor,analysis of experimental data,the relationship between pressure input and voltage output is obtained.