Optical and Electrical Methods to Measure the Dynamic Behavior of a MEMS Gyroscope Sensor

Author(s):  
Alfredo Cigada ◽  
Elisabetta Leo ◽  
Marcello Vanali

A full characterization of the mechanical parameters for vibrating MEMS sensors is required before integrating the mechanical and the electronic part. This is to verify that the main design specifications are fulfilled before sensors are available on the market. The main goal is to accurately establish the well-working devices in the shortest time. In this paper the electrical method based on the measurement of the GND current is used to satisfy this purpose. To check the validity of the achieved results through this method a comparison is done with those obtained through the widely used optical method based on vibration measurements through by means of a Laser Doppler Vibrometer (LDV).

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000359-000366 ◽  
Author(s):  
Patrick McCluskey ◽  
Chandradip Patel ◽  
David Lemus

Elevated temperatures can significantly affect the performance and reliability of MEMS gyroscope sensors. A MEMS vibrating resonant gyroscope measures angular velocity via a displacement measurement which can be on the order on nanometers. High sensitivity to small changes in displacement causes the MEMS Gyroscope sensor to be strongly affected by changes in temperature which can affect the displacement of the sensor due to thermal expansion and thermomechanical stresses. Analyzing the effect of temperature on MEMS gyroscope sensor measurements is essential in mission critical high temperature applications, such as inertial tracking of the movement of a fire fighter in a smoke filled indoor environment where GPS tracking is not possible. In this paper, we will discuss the development of the high temperature package for the tracking application, including the characterization of the temperature effects on the performance of a MEMS gyroscope. Both stationary and rotary tests were performed at room and at elevated temperatures on 10 individual single axis MEMS gyroscope sensors.


2013 ◽  
Vol 444-445 ◽  
pp. 1636-1643 ◽  
Author(s):  
Yan Hui Yuan ◽  
He Jun Du ◽  
Xin Xia ◽  
Yoke Rung Wong

In this study, capabilities of zinc oxide (ZnO) thin films in sensing and actuating were investigated using micromachined micro-cantilevers. A heterogeneous piezoelectric cantilever was modeled to study its response under voltage and/or external mechanical loading. A ZnO thin-film micro-cantilever was designed based on the developed theoretical model. Simulated tip deflections of the micro-cantilever were on the nanometer level under typical electrical and mechanical input. A prototype was fabricated with microfabrication techniques. The ZnO thin film was sputtered at room temperature and demonstrated good compatibility with common chemicals and processes in micromachining. The fabricated micro-cantilever was experimentally characterized for its actuating and sensing performance. For actuator characterization tip deflection of the micro-cantilever was detected by a laser Doppler vibrometer, while for sensor characterization the micro-cantilever was calibrated as an acceleration sensor using a reference accelerometer. The experimental resonant frequency, actuating and sensing sensitivities agreed well the design specifications.


2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Qian Zhang ◽  
Xueyun Wang ◽  
Shiqian Wang ◽  
Chaoying Pei

Microelectromechanical systems (MEMS) are core components in unmanned aerial vehicles (UAV). The precision of MEMS sensors is very important when the GPS signal is invalid. However, the precision and performance of MEMS sensors will be degraded by the changing of environment. Therefore, estimation and identification of the various noise terms existing in MEMS sensors are deemed to be necessary. The Allan variance is a common and standard method to analyze MEMS sensors, but it cannot be used to analyze the dynamic characteristics. The dynamic Allan variance (DAVAR) is a sliding version of the Allan variance. It is a practical tool that could represent the nonstationary behavior of the MEMS signal. As the DAVAR needs to estimate the Allan variance at each time epoch, the computation time grows significantly with the length of the signal series. In this paper, in the case of MEMS gyroscope on UAV, an improved fast DAVAR algorithm based on the choice of relevant time is proposed to shorten the computation time. As an experimental validation, numerical experiments are conducted under the proposed method. The results demonstrate that the improved method could greatly increase the computation speed and does not affect the accuracy of estimation.


2010 ◽  
Vol 636-637 ◽  
pp. 430-436
Author(s):  
Eugen R. Neagu ◽  
C.J. Dias ◽  
M.C. Lança ◽  
Paulo Inácio ◽  
José N. Marat-Mendes

For the characterization of the new materials and for a better understanding of the connection between structure and properties it is necessary to use more and more sensible methods to study molecular movement at nanometric scale. This paper presents the experimental basis for a new electrical method to study the fine molecular movements at nanometric scale in dielectric materials. The method will be applied for polar and non-polar materials characterization. Traditionally, the electrical methods used to study the molecular movements are based on the movements of the dipoles that are parts of the molecules. We have proposed recently a combined protocol to analyze charge injection/extraction, transport, trapping and detrapping in low mobility materials. The experimental results demonstrate that the method can be used to obtain a complex thermogram which contains information about all molecular movements, even at nanoscopic level. Actually during the charging process we are decorating the structure with space charge and during the subsequent heating we are observing an apparent peak and the genuine peaks that are related to charge de-trapping determined by the molecular movement. The method is very sensitive, very selective and allows to determinate the parameters for local and collective molecular movements, including the temperature dependence of the activation energy and the relaxation time.


Author(s):  
Tian Lu ◽  
Qinxue Chen ◽  
Zeyu Liu

Although cyclo[18]carbon has been theoretically and experimentally investigated since long time ago, only very recently it was prepared and directly observed by means of STM/AFM in condensed phase (Kaiser et al., <i>Science</i>, <b>365</b>, 1299 (2019)). The unique ring structure and dual 18-center π delocalization feature bring a variety of unusual characteristics and properties to the cyclo[18]carbon, which are quite worth to be explored. In this work, we present an extremely comprehensive and detailed investigation on almost all aspects of the cyclo[18]carbon, including (1) Geometric characteristics (2) Bonding nature (3) Electron delocalization and aromaticity (4) Intermolecular interaction (5) Reactivity (6) Electronic excitation and UV/Vis spectrum (7) Molecular vibration and IR/Raman spectrum (8) Molecular dynamics (9) Response to external field (10) Electron ionization, affinity and accompanied process (11) Various molecular properties. We believe that our full characterization of the cyclo[18]carbon will greatly deepen researchers' understanding of this system, and thereby help them to utilize it in practice and design its various valuable derivatives.


Author(s):  
Tian Lu ◽  
Qinxue Chen ◽  
Zeyu Liu

Although cyclo[18]carbon has been theoretically and experimentally investigated since long time ago, only very recently it was prepared and directly observed by means of STM/AFM in condensed phase (Kaiser et al., <i>Science</i>, <b>365</b>, 1299 (2019)). The unique ring structure and dual 18-center π delocalization feature bring a variety of unusual characteristics and properties to the cyclo[18]carbon, which are quite worth to be explored. In this work, we present an extremely comprehensive and detailed investigation on almost all aspects of the cyclo[18]carbon, including (1) Geometric characteristics (2) Bonding nature (3) Electron delocalization and aromaticity (4) Intermolecular interaction (5) Reactivity (6) Electronic excitation and UV/Vis spectrum (7) Molecular vibration and IR/Raman spectrum (8) Molecular dynamics (9) Response to external field (10) Electron ionization, affinity and accompanied process (11) Various molecular properties. We believe that our full characterization of the cyclo[18]carbon will greatly deepen researchers' understanding of this system, and thereby help them to utilize it in practice and design its various valuable derivatives.


Author(s):  
Chunming Tang ◽  
Yan Qiu ◽  
Qunying Liao ◽  
Zhengchun Zhou

Sign in / Sign up

Export Citation Format

Share Document