A Resonant Pressure Sensor Based on Wedge-Shaped Comb Excitations

This article presents a resonant pressure sensor based on electrostatic wedge-shaped comb excitations to enhance driving capabilities. The dual double-ended tuning fork resonators detect pressure through frequency shifts caused by the deformation of the pressure-sensitive diaphragm under applied pressure. The developed wedge-shaped comb drive resonators outperformed parallel-plate resonators with higher quality factors (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i> values) and better resistance to electrostatic negative stiffness effects, while also surpassing flat-shaped comb drive resonators in driving capability and achieving higher signal-to-noise ratios (SNRs). The open-loop and closed-loop experiments demonstrated that the pressure sensor achieved a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i> value of 18000 and a differential pressure sensitivity of 70 Hz/kPa, enabling high-precision measurements with an accuracy of ±0.01% full scale (FS) within a wide measurement range (temperature range: <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$- 30~^{\circ }$ </tex-math></inline-formula>C to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$135~^{\circ }$ </tex-math></inline-formula>C and pressure range: 5–350 kPa).