Modelling and characterisation of a micromachined resonant pressure sensor with piezoelectric excitation and sensing

Abstract

A resonant pressure sensor with piezoelectric excitation and sensing is presented, which is realised by combining a micromachined diaphragm and a quartz resonator. The sensor performance is improved by introducing double enhancement beams into the diaphragm. Finite element method is utilised to reveal the validity and optimise the structural dimensions. A self-excitation circuit is designed to drive the resonator into steady oscillation. The sensor chip is fabricated by bulk micromachining technologies and packaged in a metal shell in the inert gas environment for characterisation. The performance characteristics including the short-term drift, temperature characteristic and quality factor are investigated. The experimental results demonstrate that the sensor features a high sensitivity of 100.45 Hz/kPa and a short-term drift <14 ppm in the operating range of −10∼10 kPa at room temperature. Owing to the excellent performance in sensitivity and accuracy, the sensor can be applied for micropressure measurement.

A High-Precision Quartz Resonant Ultra-High Pressure Sensor with Integrated Pressure Conversion Structure

“…In summary, the shape of the quartz DETF resonator structure was completed through wet etching, and the surface electrodes are made by sputtering [ 17 ]. In order to solve the production problem of side electrodes, a process scheme combining mechanical hard mask and inclined sputtering was adopted.…”

Resonance frequency analysis of a dual-frequency capacitive micromechanical ultrasonic transducer for detecting high and low pressures simultaneously with high sensitivity and linearity

“…A silicon resonant pressure sensor, which measures external pressure by detecting a change in the resonance frequency, is a typical example of high-precision pressure sensors [11]. The most common silicon resonant pressure sensor has a composite structure of a pressure-sensitive diaphragm and a resonator that is fixed on the surface of the diaphragm.…”