A Resonant Pressure Microsensor with the Measurement Range of 1 MPa Based on Sensitivities Balanced Dual Resonators

This paper presents a resonant pressure microsensor with the measurement range of 1 MPa suitable for the soaring demands of industrial gas pressure calibration equipment. The proposed microsensor consists of an SOI layer as a sensing element and a glass cap for vacuum packaging. The sensing elements include a pressure-sensitive diaphragm and two resonators embedded in the diaphragm by anchor structures. The resonators are excited by a convenient Lorentz force and detected by electromagnetic induction, which can maintain high signal outputs. In operation, the pressure under measurement bends the pressure-sensitive diaphragm of the microsensor, producing frequency shifts of the two underlining resonators. The microsensor structures were designed and optimized using finite element analyses and a 4” SOI wafer was employed in fabrications, which requires only one photolithographic step. Experimental results indicate that the Q-factors of the resonators are higher than 25,000 with a differential temperature sensitivity of 0.22 Hz/°C, pressure sensitivities of 6.6 Hz/kPa, and −6.5 Hz/kPa, which match the simulation results of differential temperature sensitivity of 0.2 Hz/°C and pressure sensitivities of ±6.5 Hz/kPa. In addition, characterizations based on a closed-loop manner indicate that the presented sensor demonstrates low fitting errors within 0.01% FS, high accuracy of 0.01% FS in the pressure range of 20 kPa to 1 MPa and temperature range of −55 to 85 °C, and the long-term stability within 0.01% FS in a 156-day period under the room temperature.

[1]  Junbo Wang,et al.  A Resonant Pressure Microsensor Based on Double-Ended Tuning Fork and Electrostatic Excitation/Piezoresistive Detection , 2018, Sensors.

[2]  P. Kinnell,et al.  Advances in Silicon Resonant Pressure Transducers , 2009 .

[3]  Mario Kupnik,et al.  An Analytical Model for Capacitive Pressure Transducers With Circular Geometry , 2018, Journal of microelectromechanical systems.

[4]  J. Greenwood,et al.  A high accuracy resonant pressure sensor by fusion bonding and trench etching , 1999 .

[5]  Junbo Wang,et al.  A Micromachined Silicon Resonant Pressure Sensor , 2017 .

[6]  Xiaodong Sun,et al.  Design and Analysis of a New Tuning Fork Structure for Resonant Pressure Sensor , 2016, Micromachines.

[7]  Fujing Xu,et al.  Modeling and Studying Acceleration-Induced Effects of Piezoelectric Pressure Sensors Using System Identification Theory , 2019, Sensors.

[8]  Jijun Xiong,et al.  Fiber-optic Fabry-Perot pressure sensor based on sapphire direct bonding for high-temperature applications. , 2019, Applied optics.

[9]  Julian W. Gardner,et al.  A laterally driven micromachined resonant pressure sensor , 1996 .

[10]  Angus R. Simpson,et al.  Wave separation and pipeline condition assessment using in-pipe fibre optic pressure sensors , 2019, Journal of Hydroinformatics.

[11]  Junbo Wang,et al.  A High-Q Resonant Pressure Microsensor with Through-Glass Electrical Interconnections Based on Wafer-Level MEMS Vacuum Packaging , 2014, Sensors.

[12]  Xiaohui Du,et al.  Laterally Driven Resonant Pressure Sensor with Etched Silicon Dual Diaphragms and Combined Beams , 2016, Sensors.

[13]  Kurt E. Petersen,et al.  Resonant beam pressure sensor fabricated with silicon fusion bonding , 1991, TRANSDUCERS '91: 1991 International Conference on Solid-State Sensors and Actuators. Digest of Technical Papers.

[14]  Junbo Wang,et al.  A Resonant Pressure Microsensor Capable of Self-Temperature Compensation , 2015, Sensors.

[15]  J. Sacristan,et al.  Differential capacitive pressure sensor design based on standard CMOS , 2017 .

[16]  Kyoichi Ikeda,et al.  Various applications of resonant pressure sensor chip based on 3-D micromachining , 1999 .

[17]  S. Beeby,et al.  MEMS Mechanical Sensors , 2004 .

[18]  José Luis Ocaña,et al.  Design, fabrication and characterization of an annularly grooved membrane combined with rood beam piezoresistive pressure sensor for low pressure measurements , 2018, Sensors and Actuators A: Physical.

[19]  Yoshida Takashi,et al.  Three-dimensional micromachining of silicon pressure sensor integrating resonant strain gauge on diaphragm , 1990 .

[20]  Fan Yang,et al.  Accurate measurement of high-frequency blast waves through dynamic compensation of miniature piezoelectric pressure sensors , 2018, Sensors and Actuators A: Physical.

[21]  John Greenwood,et al.  High accuracy pressure measurement with a silicon resonant sensor , 1993 .

[22]  James H. Smith,et al.  Micromachined pressure sensors: review and recent developments , 1997 .

[23]  Junbo Wang,et al.  A Lateral Differential Resonant Pressure Microsensor Based on SOI-Glass Wafer-Level Vacuum Packaging , 2015, Sensors.

[24]  Ernst Obermeier,et al.  Piezoresistive pressure sensors based on polycrystalline silicon , 1991 .

[25]  J. Greenwood.  Etched silicon vibrating sensor , 1984 .