Effect of the Detector Width and Gas Pressure on the Frequency Response of a Micromachined Thermal Accelerometer

Garraud, Alexandra; Combette, Philippe; Courteaud, J.; Giani, Alain

doi:10.3390/mi2020167

Cited by 10 publications

(8 citation statements)

References 11 publications

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“…Figure 7 b clearly shows that the relationship between the sensitivity and frequency according to the types of gas media produces the same result as that between the sensitivity and frequency in terms of the volume of the top wafer. Figure 7 b shows that the gas media with smaller densities and larger thermal diffusivities have wider frequency bands [ 25 , 26 ]. The gases that have a smaller density can move faster than those with a larger density, giving a widened bandwidth.…”

Section: Resultsmentioning

confidence: 99%

“…Figure 8 a shows that an increase in pressure was accompanied by an improvement in sensitivity because the pressure increase led to the increase in the gas density, which increased Gr, thereby improving the sensitivity. This result is very significant as it indicates that high-pressure packaging could reduce energy consumption and improve sensitivity without any structural modification or additional increases in the heater power [ 23 , 24 , 25 , 26 , 27 ]. It is one of the great advantages that is introduced by using a gas medium instead of a liquid one in the proposed thermal convection-based accelerometer.…”

Section: Resultsmentioning

confidence: 99%

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Multi-axis Response of a Thermal Convection-based Accelerometer

et al. 2018

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A thermal convection-based accelerometer was fabricated, and its characteristics were analyzed in this study. To understand the thermal convection of the accelerometer, the Grashof and Prandtl number equations were analyzed. This study conducted experiments to improve not only the sensitivity, but also the frequency band. An accelerometer with a more voluminous cavity showed better sensitivity. In addition, when the accelerometer used a gas medium with a large density and small viscosity, its sensitivity also improved. On the other hand, the accelerometer with a narrow volume cavity that used a gas medium with a small density and large thermal diffusivity displayed a larger frequency band. In particular, this paper focused on a Z-axis response to extend the performance of the accelerometer.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Multi-axis Response of a Thermal Convection-based Accelerometer

et al. 2018

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“…Since then, many studies have been conducted on these sensors. Most of the studies have focused on improving the sensor performance by optimizing the fluid medium with proper thermal properties (e.g., thermal conductivity, thermal diffusivity, kinematic viscosity), temperature sensing (e.g., thermal couple, thermistor), the material of the thermistor (e.g., metal thermistor, polysilicon thermistor, silicon PN junction thermistor) and the structure of the sensor (e.g., cavity shape and size, cap shape and size, distribution and size of the heater and thermistors) [ 6 , 7 , 8 , 9 , 10 , 11 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ]. Combinations of Finite-Element-Modeling (FEM) simulation and experimental validation are the most commonly-used research methods.…”

Section: Introductionmentioning

confidence: 99%

Micromachined Fluid Inertial Sensors

Liu

Zhu

2017

Sensors

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Micromachined fluid inertial sensors are an important class of inertial sensors, which mainly includes thermal accelerometers and fluid gyroscopes, which have now been developed since the end of the last century for about 20 years. Compared with conventional silicon or quartz inertial sensors, the fluid inertial sensors use a fluid instead of a solid proof mass as the moving and sensitive element, and thus offer advantages of simple structures, low cost, high shock resistance, and large measurement ranges while the sensitivity and bandwidth are not competitive. Many studies and various designs have been reported in the past two decades. This review firstly introduces the working principles of fluid inertial sensors, followed by the relevant research developments. The micromachined thermal accelerometers based on thermal convection have developed maturely and become commercialized. However, the micromachined fluid gyroscopes, which are based on jet flow or thermal flow, are less mature. The key issues and technologies of the thermal accelerometers, mainly including bandwidth, temperature compensation, monolithic integration of tri-axis accelerometers and strategies for high production yields are also summarized and discussed. For the micromachined fluid gyroscopes, improving integration and sensitivity, reducing thermal errors and cross coupling errors are the issues of most concern.

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“…It includes the thin membrane for pressure measurement, the heater and thermister for thermal-related applications, and the free-standing structure with excellent thermal isolation for high temperature platforms. The microhotplate fabricated by microelectromechanical systems (MEMS) technology has been widely used for gas pressure sensors, gas sensors, chemical sensors, flow sensors, and accelerometers [8][9][10][11][12][13]. It could also be implemented in the standard CMOS process for high yield and low cost.…”

Section: Introductionmentioning

confidence: 99%

Multifunctional Platform with CMOS-Compatible Tungsten Microhotplate for Pirani, Temperature, and Gas Sensor

Wang¹,

Yu²

2015

Micromachines

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Abstract:A multifunctional platform based on the microhotplate was developed for applications including a Pirani vacuum gauge, temperature, and gas sensor. It consisted of a tungsten microhotplate and an on-chip operational amplifier. The platform was fabricated in a standard complementary metal oxide semiconductor (CMOS) process. A tungsten plug in standard CMOS process was specially designed as the serpentine resistor for the microhotplate, acting as both heater and thermister. With the sacrificial layer technology, the microhotplate was suspended over the silicon substrate with a 340 nm gap. The on-chip operational amplifier provided a bias current for the microhotplate. This platform has been used to develop different kinds of sensors. The first one was a Pirani vacuum gauge ranging from 10´1 to 10 5 Pa. The second one was a temperature sensor ranging from´20 to 70˝C. The third one was a thermal-conductivity gas sensor, which could distinguish gases with different thermal conductivities in constant gas pressure and environment temperature. In the fourth application, with extra fabrication processes including the deposition of gas-sensitive film, the platform was used as a metal-oxide gas sensor for the detection of gas concentration.

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Effect of the Detector Width and Gas Pressure on the Frequency Response of a Micromachined Thermal Accelerometer

Cited by 10 publications

References 11 publications

Multi-axis Response of a Thermal Convection-based Accelerometer

Multi-axis Response of a Thermal Convection-based Accelerometer

Micromachined Fluid Inertial Sensors

Multifunctional Platform with CMOS-Compatible Tungsten Microhotplate for Pirani, Temperature, and Gas Sensor

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