| In today's society,with the development of Internet technology,people are about to enter the era of the Internet of Things,and all aspects of people's lives are moving towards digital and informational development.Sensors are an important means to realize the digitization of information,especially as MEMS technology becomes more mature.Micro-heat plate micro-gas sensors are more and more widely used.Their miniaturized volume,high-efficiency heating rate and the advantages of IC circuit integration make micro-structured gas sensors more advantageous than traditional ceramic tube sensors.This paper mainly designed Three kinds of new micro-heat plate gas sensor,the use of finite element method on the sensor's substrate,heating electrode,signal electrode,magnetic field distribution and gas sensor material optimization analysis,to find the optimal design parameters,making the sensor's overall performance best.1.Design and optimization of type A micro hot plate gas sensorThe I-type micro hot plate type gas sensor designed has a rectangular parallelepiped structure and a serpentine heating electrode,at the same time the thickness of the base three layers of the sensor,the width and spacing of the heating electrodes,and the width parameters of the measuring electrodes were optimized.The results show that when the thickness of the insulating layer,heat-conducting layer and protective support layer in the sensor substrate are 5?m,225?m,70?m respectively,both of heating electrode width and measuring electrode width are 20?m,the best temperature and magnetic field distributions can be obtained in the work area of the gas sensor,which is helpful to improve the whole performance of the sensor.2.Design and optimization of type B micro hot plate gas sensorThe substrate shape of the designed typeII micro-heat plate gas sensor is a rectangular parallelepiped structure,and its size is 1.225mm×1.225mm×0.3mm.After being analyzed by the finite element method,the conclusion is drawn:The base of the micro hot plate sensor is a three-layer structure,which structure has dimensions of1?m,189?m,and 110?m,respectively.The width and spacing of the heating electrodes are 20?m,the width of the signal electrode is 40?m,and the temperature of the working area in the center of the microplate is 353.019°C,and the temperature difference is 0.22?,and the magnetic field size of the working area is 2.4×10-1111 T,which is extremely different from the maximum value of 7.8×10-3 T at the heating electrode,and has little interference with the measurement signal.3.Design and optimization of type C micro hot plate gas sensorThe A novel structure was designed for micro gas sensor,and the micro gas sensor was analyzed by using finite element analysis tool,at the same time The thickness of the base three layers of the sensor,the width and spacing of the heating electrodes,and the width parameters of the measuring electrodes were optimized.Research shows that when the thickness of the three-layer sensor substrate is 5?m,235?m,and 60?m,respectively,both of heating electrode spacing and measuring electrode width are 30?m,and heating electrode wide is 20?m,the best temperature and magnetic field distributions can be obtained in the work area of the gas sensor,which is helpful to improve the whole performance of the sensor.4.Comparison of various performance parameters of three kinds of micro-heat plate gas sensorsBoth Type I and Type II sensor substrates are cuboids and have a volume of approximately 0.45mm3.The former heating electrode has a traditional serpentine structure.The temperature in the central working area is 351.905 ?.The temperature difference in the central area is 0.221 ? and the magnetic induction intensity is 1.22×10-9T.The latter heating electrode is a'back'shape structure,using a double-loop four-phase layout,the central working area temperature is 353.019 ?,the center temperature difference is 0.22 ?,and the magnetic induction intensity is 2.4×10-11T,which is higher than the previous one.Under the same conditions,the temperature is higher.The base of the Type III sensor is a cylinder.After cutting off two symmetrical circular arcs,the volume is about 1.5mm2.The heating electrode also adopts a double-loop four-phase layout,and the central area has a working temperature of 351.936 ?.The temperature difference is 0.125 ? and the magnetic induction intensity is 1.68×10-11 T.In the middle of the three,the temperature is in the middle and the magnetic induction intensity is the lowest.Therefore,the type II structure has the highest working temperature under the same conditions.5.Comparison of three micro hot plate gas sensors based on ZnOThe micro hot plate is the core heating device of the sensor and provides a suitable working temperature for the ZnO gas sensitive material.The gas sensitive material has a high selectivity for a certain gas at a certain temperature.Therefore,the temperature field distribution of the sensor micro hot plate is Uniformity has a great influence on the selectivity of the sensor.Under the same heating power,the temperature of the working area of ZnO gas sensor of type A sensor is about315.328?,and the temperature difference is 0.336?.The temperature of working area of ZnO gas sensor of type B sensor is about 317.688?,and the temperature difference is 0.217?,C-type sensor gas sensor working area temperature is about315.956 ?,the temperature difference is 0.230?,so the B-type sensor gas sensor work area temperature is highest,C type followed,A type lowest. |
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