A Resonant High Pressure Sensor Based on Dual Cavities Design

This paper presents a new type of resonant high-pressure sensor with measuring range of 100 MPa, which composed of SOI layer and a glass cap. Frequency shifts of resonators caused by bending pressure sensitive diaphragm under high pressure. The sensor structure was optimized by using finite element analysis to meet the applications in the fields of the ocean science and the petrochemical industry, especially in the packaging strength and sensitivities. In addition, the sensor chip was fabricated by simplified SOI-MEMS fabrication technology, including only two photolithography steps. The experimental results show that 1) the sensor structure can withstand a pressure of 100 MPa; 2) the pressure sensitivity of the dual resonators is −0.0677 kHz/MPa (resonator I) and 0.0649 kHz/MPa (resonator II) respectively, which meets the requirements of the ocean science and the petrochemical industry.