Numerical modeling accuracy assessment and optimization of a piezoresistive silicon pressure sensor
Artur Wymysłowski · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2001
This paper deals with a numerical modeling and optimization of a piezoresistive silicon pressure senor with an etched membrane and diffused piezo resistors. The mentioned sensor utilizes resistance changes of piezo resistors placed on the stressed membrane. Th stress is induced by the differential pressure applied to the membrane. Presented numerical modeling of the pressure sensor was based on theory of piezo resistivity and finite element modeling (FEM). Theory of piezoresistivity allowed for calculating the resistance changes of piezo resistors while FEM allowed for calculating the stress distribution. Applied modeling procedure provided a direct insight into an output signal of the sensor under loading. The main problem of numerical modeling is an accuracy of the achieved results. Because of our reduced knowledge on physical phenomena's, material properties and inherent inaccuracy of numerical methods nay engineer should be aware of the limited accuracy of numerical modeling. There are a number of methods that allow at least to assess roughly the error of modeling but there is still a lot of work to do. Therefore it is the rule of thumb that results of modeling should be always verified with the experiment whenever it is possible.