Resonant beam pressure sensor fabricated with silicon fusion bonding

A resonant pressure sensor has been fabricated which consists of a single-crystal silicon beam located in the center of a single-crystal silicon diaphragm. The beam is excited electrostatically and its motion are detected by piezoresistors. The structure is fabricated with silicon fusion bonding. Overall measurement accuracies of 0.01% have been achieved. This sensor has been designed to meet the exacting standards required for aerospace air data computers and engine control applications where achievable accuracies of 0.1% absolute pressure are required. The principle of operation is imply to measure the change in resonant frequency of a micromachined silicon beam as the pressure exerted on the sensor´s diaphragm is changed.<>