Abstract:
Pressure sensors are used in a wide range of applications with a significant market share in the industrial sector. The piezoresistive pressure sensor is quite popular due to its low production cost. It is normally made up of sensing elements attached to a deformation membrane. The analysis of the mechanical deformation in the elastic element of the sensors plays a critical role in its design. In this paper, the design of a pressure sensor with semiconductor piezoresistive elements was tested and validated via simulation with the COMSOL software. The emphasis was put on the evaluation of the membrane thermal expansion effect on the overall pressure sensor operation. This observation allowed the conduction of a study to minimize the observed thermal effect. Through the simulation it was also possible to evaluate different arrangements and positioning of the semiconductor sensors in order to obtain the best sensitivity and less non-linearity. The best adhesive for the semiconductor resistors attachment was determined through experimental sensitivity and creeping tests. The complete pressure sensor was then prototyped and fully characterized. The final experimental results confirmed the simulated data and the proposed method for reducing the sensor temperature sensitivity.
Keywords:
Pressure sensor, Piezoresistor, Displacement analysis.
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