• MEMS
• pressure sensor
• capacitance
• substrate deformation

MEMS pressure sensors are tiny systems fabricated with technologies inherited from integrated circuits. In this work, after a general introduction on the manufacturing techniques of such systems, an overview on the main types of MEMS pressure sensors and their field of use, is made. Among them, greater attention is given to pressure sensors exploiting capacitive and piezoresistive transduction techniques.
The aim of the work is to study and design a new capacitive pressure sensor and compare its performances with the ones of an existing piezoresistive device designed by Hanking Electronics. For this purpose, three possible design variants of the capacitive pressure sensor are analysed. An original theoretical model is developed in order to easily calculate a first estimate of the optimal design, based on technical specifications and fabrication constraints. FEM simulations, including both electrical and mechanical domains, are then performed to finalize the design. Simulations are performed not only with respect to pressure, but also to substrate and thermal deformations, which are a well-known source of disturbance for these types of sensors.