Mikroişlenmiş basınç sensörü

Capacitive Micromachined Ultrasonic Transducer (CMUT) is a microelectromechanical device that is basically formed by a moving top electrode, a stable bottom electrode and a gap in between. In spite of its this simple mass-spring construction, CMUT is a nonlinear device and its working principles have been formulated. According to these studies, the top electrode can be set in motion by the applied pressure on it and by depending on the amount of that pressure, the resonant frequency of the CMUT can be altered. Therefore, it is possible to use CMUT to obtain a pressure sensor. In this respect, what we have to do is keep tracking of its resonant frequency to deduce the pressure. The most effective way of doing it, on the other hand, is using an oscillator circuit which also provides us the capability of tracking the resonant frequency in real time. Also, to design an integrated circuit that works with the CMUT, the best way is utilizing a Colpitts oscillator. In this thesis, we design a pressure sensor with CMUT based Colpitts oscillator.