Design and Analysis of a New Tuning Fork Structure for Resonant Pressure Sensor

Sun, Xiaodong; Yuan, Weizheng; Qiao, Deli; Sun, Ming; Ren, Sen

doi:10.3390/mi7090148

Cited by 15 publications

(16 citation statements)

References 12 publications

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“…Resonant pressure micro sensors, which are featured with high resolutions, high accuracies, excellent long-term stabilities, and quasi-digital outputs, are widely used in the fields of industrial control, aerospace aviation, and meteorology [1,2,3,4]. As to excitation and detection of resonators, resonant pressure sensors can work based on electrothermal excitation/piezoresistive detection [5,6], electrostatic excitation/capacitive detection [7,8], electromagnetic excitation/electromagnetic detection [9,10], and electrostatic excitation/piezoresistive detection [11,12]. Compared with other types of resonant pressure sensors, the sensors based on electrostatic excitation/piezoresistive detection are featured with high SNRs and simple structures, and thus this type of resonant pressure sensor is under the intensive studies [13].…”

Section: Introductionmentioning

confidence: 99%

Resonant Pressure Micro Sensors Based on Dual Double Ended Tuning Fork Resonators

Zhang

Yan

et al. 2019

Micromachines

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This paper presents resonant pressure micro sensors based on dual double ended tuning fork (DETF) resonators, which are electrostatically excited and piezoresistively detected. In operation, the barometric pressure under measurement bends the pressure sensitive diaphragm functioning as the anchor of DETF resonators and therefore produces eigenfrequency shifts of the resonators. Theoretical analyses and finite element analyses (FEA) were conducted to optimize the key geometries of the DETF resonators with enhanced signal to noise ratios (SNRs). In fabrications, key steps including deep reactive ion etching (DRIE) and anodic bonding were used, where sleeve holes were adopted to form electrical connections, leading to high-efficiency structure layout. Experimental results indicate that the presented micro sensors produced SNRs of 63.70 ± 3.46 dB in the open-loop characterizations and differential sensitivities of 101.3 ± 1.2 Hz/kPa, in the closed-loop characterizations. In addition, pressure cycling tests with a pressure range of 5 to 155 kPa were conducted, revealing that the developed micro sensors demonstrated pressure shifts of 83 ± 2 ppm, pressure hysteresis of 67 ± 3 ppm, and repeatability errors of 39 ± 2 ppm. Thus, the developed resonant pressure micro sensors may potentially function as an enabling tool for barometric pressure measurements.

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Section: Introductionmentioning

confidence: 99%

Resonant Pressure Micro Sensors Based on Dual Double Ended Tuning Fork Resonators

Zhang

Yan

et al. 2019

Micromachines

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“…As reported 12 , in the out-of-plane resonant mode, the vibration direction of the resonator is perpendicular to the diaphragm, resulting in substantial energy loss from the resonator to the diaphragm, which will decrease the Qfactor. Even for the in-plane common side mode, there is still a reaction force that is transferred to the diaphragm from the resonator due to the unbalanced dynamic structure; the quality factor will also be influenced by the diaphragm conditions, such as the width and thickness.…”

Section: Design Of the Resonant Pressure Sensor Chipmentioning

confidence: 91%

“…Resonant pressure sensors based on capacitive detection methods have attracted considerable attention from researchers because they are easy to fabricate and have simple structures 4,6,12,13 . Ren et al 13 proposed a resonant pressure sensor on the basis of the principle of the capacitive detection method; the sensor showed a sensitivity of 8 Hz/kPa with a silicon on insulator wafer, and its total accuracy exceeded 0.05% full scale (FS), but the quality factor was small because a vacuum package was not used.…”

Section: Introductionmentioning

confidence: 99%

“…Du et al 5 developed a resonant pressure sensor based on another capacitive detection with silicon fusion bonding and a silicon island amplifier; it had a good linearity of 0.02% FS and a sensitivity of 10 Hz/kPa. These capacitive detection-based resonant pressure sensors showed that the change in the detection capacitance was extremely small, requiring a signal amplifier circuit with an extremely large amplification factor; meanwhile, the crosstalk between an excitation comb and capacitance detection comb was hard to eliminate 12 . Electromagnetic detection-based resonant pressure sensors have been comprehensively researched by Li et al 11 and Lu et al 14 ; these sensors have a total accuracy that is >0.01% FS.…”

Section: Introductionmentioning

confidence: 99%

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Novel resonant pressure sensor based on piezoresistive detection and symmetrical in-plane mode vibration

et al. 2020

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In this paper, a novel resonant pressure sensor is developed based on electrostatic excitation and piezoresistive detection. The measured pressure applied to the diaphragm will cause the resonant frequency shift of the resonator. The working mode stress–frequency theory of a double-ended tuning fork with an enhanced coupling beam is proposed, which is compatible with the simulation and experiment. A unique piezoresistive detection method based on small axially deformed beams with a resonant status is proposed, and other adjacent mode outputs are easily shielded. According to the structure design, high-vacuum wafer-level packaging with different doping in the anodic bonding interface is fabricated to ensure the high quality of the resonator. The pressure sensor chip is fabricated by dry/wet etching, high-temperature silicon bonding, ion implantation, and wafer-level anodic bonding. The results show that the fabricated sensor has a measuring sensitivity of ~19 Hz/kPa and a nonlinearity of 0.02% full scale in the pressure range of 0–200 kPa at a full temperature range of −40 to 80 °C. The sensor also shows a good quality factor >25,000, which demonstrates the good vacuum performance. Thus, the feasibility of the design is a commendable solution for high-accuracy pressure measurements.

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“…This sensor uses a hammock resonator as a sensing element and the Q-factor is insensitive to the leakage of cavity gases due to the laterally driven principle. Due to the benefits of being laterally driven, Sun et al presented a micromachined resonant pressure sensor based on an electrostatic excited/capacitance detected resonator in 2016 [20]. Experiment results showed that the sensor had a pressure sensitivity of ~29 Hz/kPa, a nonlinearity of 0.02% FS, a hysteresis error of 0.05% FS within the pressure measurement range of 20 to 280 kPa, and the temperature sensitivity of the resonator was ~2 Hz/°C in the temperature range of −40 to 80 °C.…”

Section: Introductionmentioning

confidence: 99%

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

Yan

Xiang

et al. 2019

Sensors

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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.

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Design and Analysis of a New Tuning Fork Structure for Resonant Pressure Sensor

Cited by 15 publications

References 12 publications

Resonant Pressure Micro Sensors Based on Dual Double Ended Tuning Fork Resonators

Resonant Pressure Micro Sensors Based on Dual Double Ended Tuning Fork Resonators

Novel resonant pressure sensor based on piezoresistive detection and symmetrical in-plane mode vibration

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

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