SILICON PRESSURE SENSOR INTEGRATES RESONANT STRAIN-GAUGE ON DIAPHRAGM

A novel silicon pressure sensor has been developed which will enable high-precision pressure measurement. The sensor, which is based on a new concept, is fabricated from a single silicon crystal and has two resonant strain gauges which are held in vacuum cavities on the surface of the diaphragm to isolate them from the surrounding fluid. The two oscillating frequencies of the resonant strain gauges are differentially modulated by pressure. The sensor's measuring principle, features, its amplitude-controlled self-oscillation circuit, and the results of experiments are given. © 1990.