Capacitive Pressure Sensor With Very Large Dynamic Range

Bakhoum, Ezzat G.; Cheng, Hung-Ming

doi:10.1109/tcapt.2009.2022949

Cited by 61 publications

(29 citation statements)

References 11 publications

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“…We shall therefore replace in (7) by , where is the peak value of the acceleration. Equation (7) then yields (8) From (3) and (8), we conclude that (9) If the sensor is subjected to a frequency , the above expression will reduce to (10) where was determined to be approximately equal to 0.8 for the present sensor (see Section III-B). For a capacitance in the pico-Farad range, it can be seen that the detectable acceleration will be on the order of m/s , or .…”

Section: B Sensing Of Vibrationsmentioning

confidence: 93%

“…In addition, a highly sensitive pressure sensor (a sensor with a capability to detect pressures of less than one Pascal) will be very useful for a new class of biological and molecular sensing applications [7], [8]. It has recently been demonstrated that sensors based on variable capacitance can offer the highest sensitivity among all known types of pressure/vibration sensing mechanisms [9]- [13]. However, capacitive pressure/vibration sensors still cannot offer the ultrahigh sensitivity that is needed for demanding applications such as earthquake prediction and the detection of very small pressures in biological processes.…”

Section: Introductionmentioning

confidence: 99%

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Ultrahigh-Sensitivity Pressure and Vibration Sensor

Bakhoum

Cheng

2011

IEEE Sensors J.

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A novel new ultrahigh-sensitivity pressure and vibration sensor is introduced. The sensor is based on the concept of using a variable ultracapacitor rather than a variable capacitor as a transduction mechanism. The variable ultracapacitor assembly consists of two electrodes on which carbon nano-tubes of a length of 20 m are grown. One electrode is fixed and is fully immersed in the electrolyte, while the other electrode is movable and is positioned outside of the electrolyte. In response to pressure or vibration, an extremely small displacement of 20 m (less than the width of a human hair) submerges the movable electrode into the electrolyte and results in a substantially large variation in capacitance (from zero to 54 F in the present prototype).Index Terms-High-sensitivity transducer, pressure sensor, variable ultracapacitor, vibration sensor.

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Section: B Sensing Of Vibrationsmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Ultrahigh-Sensitivity Pressure and Vibration Sensor

Bakhoum

Cheng

2011

IEEE Sensors J.

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“…But in the industrial security zone, against bad conditions, micro pressure leak in confined Spaces and test requirements for pipeline microflow have not been satisfied, need small size, high anti-interference, high sensitivity, micropressure sensor products with wide range and not lose the precision. In recent years, the development direction of micropressure sensor is starting to shift to new materials, new mechanism and new structure, the process is being developed from silicon micropressure sensor [3,4] to optical micropressure sensor.…”

Section: Introductionmentioning

confidence: 99%

Fiber fabry-pero micro pressure sensor

Xia

Wang

2017

MATEC Web Conf.

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Abstract:A new fiber fabry-perot pressure sensor is designed. It is made by photolithography, silicon wafer etching, anode bonding, microelectromechanical system technology and so on. It is suitable for the pressure measurement of micro-pressure environment under harsh environment and small space. The structure of the transmitter and the way to make it are described in detail. The design smartly uses the Fiber optic flange, the optical fiber end face is parallel to the sensitive film, thus a high-quality Fabry-Pero-cavity is formed. The structure also contributes to the stability of the initial cavity, the sensor error is reduced. The experimental demodulation system is established, the pressure, temperature and other characteristics are tested in detail.The experiment result shows that within the pressure range of 0~0.1MPa, the sensor has a good linearity, high repeatability and a sensitivity of 61.6  m/MPa.

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“…Typically, a constant pressure is fed to one side of the diaphragm using a pressure chamber while the other side encounters the variable pressure to be measured. The diaphragm deformation can be measured using different mechanisms, including optical [6], capacitive [7], piezoresistive [8] and resonant frequency shift [9], [10] methods. Among such, resonant pressure sensors have the advantages of simplifying readout system by providing an output frequency that can be directly fed into a computer (no need for A/D conversion), long term stability and higher resolution.…”

Section: Introductionmentioning

confidence: 99%

Thermal-Piezoresistive Resonators and Self-Sustained Oscillators for Gas Recognition and Pressure Sensing

Guo

Pourkamali

2013

IEEE Sensors J.

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This paper presents experimental and theoretical investigation of the response of microscale dual-plate thermalpiezoresistive resonators (TPRs) and self-sustained oscillators (TPOs) to different gases and pressures. It is demonstrated that the resonant frequency of such devices follow particular trends in response to the changes in the surrounding gas and its pressure. A mathematical model is derived to explain the damping dependent frequency shift characteristic of the TPO. The solution of the model indicates that the stiffness of the actuator beam decreases as the value of the damping coefficient drops at lower gas density caused by the change in the gas molecular mass or pressure. When operated in the TPR mode (linear operation), however, the frequency shift of the same silicon structure is mainly a function of gas thermal conductivity. The two different sensing mechanisms are confirmed by the measurement results showing opposite frequency shift for the TPR and TPO in helium-nitrogen mixtures. In pressure tests, frequency shifts as high as −2300 ppm are measured for a TPO by changing the air pressure from 84 to 43 kPa.

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Capacitive Pressure Sensor With Very Large Dynamic Range

Cited by 61 publications

References 11 publications

Ultrahigh-Sensitivity Pressure and Vibration Sensor

Ultrahigh-Sensitivity Pressure and Vibration Sensor

Fiber fabry-pero micro pressure sensor

Thermal-Piezoresistive Resonators and Self-Sustained Oscillators for Gas Recognition and Pressure Sensing

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