Design Optimization for Non-Resonant MEMS Gyroscope

2009 ◽  
Author(s):  
Wei Cui ◽  
Xiaolin Chen ◽  
Wei Xue
Keyword(s):  
Device Performance ◽  
Sense Mode ◽  
Drive Mode ◽  
Resonant Frequencies ◽  
Frequency Matching ◽  
Wide Range ◽  
Mems Gyroscopes ◽  
Capacitive Mems ◽  
Effective Design ◽  
Model Approach

Conventional capacitive MEMS gyroscopes require close matching between the resonant frequencies of drive mode and sense mode. However, the uncertainties in the microfabrication process impair the robustness of the gyroscopes and often lead to unpredictable device performance. This paper analyzes a 4 degree-of-freedom (DOF) non-resonant gyroscope which is less vulnerable to the fabrication perturbations. Unlike the conventional resonant gyroscope which has only one resonant frequency for drive and sense modes, the 4-DOF gyroscope includes two resonant frequencies for each mode. The non-resonant gyroscope design aims to reduce resonance frequency matching, namely to minimize the effect of the inevitable fabrication uncertainties as well as to increase the bandwidth with less sacrifice to the sensitivity. The device performance is analyzed and optimized by the behavior model approach in CoventorWare which significantly accelerates the simulation compared to the traditional finite element method. The optimized non-resonant gyroscope with higher fabrication tolerance as well as enhanced device performance is proven to be an effective design and can be used in a wide range of applications.

scholarly journals A Decoupling Design with T-Shape Structure for the Aluminum Nitride Gyroscope

Micromachines ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 244
Author(s):  
Yang ◽  
Si ◽  
Han ◽  
Zhang ◽  
Ning ◽  
...  
Keyword(s):  
Aluminum Nitride ◽  
Microelectromechanical Systems ◽  
Sense Mode ◽  
Drive Mode ◽  
Aln Film ◽  
Shape Structure ◽  
Mems Gyroscopes ◽  
Sense Electrode ◽  
Working Principle ◽  
Novel Design

This paper reports a novel design for the decoupling of microelectromechanical systems (MEMS) gyroscopes. The MEMS gyroscope is based on piezoelectric aluminum nitride (AlN) film, and the main structure is a mass hung by T-shape beams. A pair of parallel drive electrodes are symmetrically placed on the surface of the vertical bar for driving the oscillating mass. A serpentine sense electrode is placed on the lateral bar. When the gyroscope is oscillating in drive mode, charges with equal quantity and opposite sign will be polarized and distributed symmetrically along the lateral bar. These charges neutralize each other at the sense electrode. Therefore, no coupling signals can be detected from the sense electrode. This design can realize the decoupling between the drive mode and sense mode. In this work, the T-shape decoupled structure was designed as the key component of an AlN piezoelectric gyroscope and the whole structure was simulated by COMSOL Multiphysics 5.2a. The working principle of the decoupling is described in detail. Electrical properties were characterized by the dynamic signal analyzer. According to the test results, the drive mode and the sense mode are decoupled. The coefficient of orthogonal coupling is 1.55%.

scholarly journals Gas Damping in Capacitive MEMS Transducers in the Free Molecular Flow Regime

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2566
Author(s):  
Boris A. Boom ◽  
Alessandro Bertolini ◽  
Eric Hennes ◽  
Johannes F. J. van den Brand
Keyword(s):  
Flow Regime ◽  
Gas Diffusion ◽  
Diffusion Time ◽  
Molecular Flow ◽  
Free Molecular Flow ◽  
Simple Analytical Model ◽  
Gas Damping ◽  
Wide Range ◽  
Capacitive Mems ◽  
Insight Into

We present a novel analysis of gas damping in capacitive MEMS transducers that is based on a simple analytical model, assisted by Monte-Carlo simulations performed in Molflow+ to obtain an estimate for the geometry dependent gas diffusion time. This combination provides results with minimal computational expense and through freely available software, as well as insight into how the gas damping depends on the transducer geometry in the molecular flow regime. The results can be used to predict damping for arbitrary gas mixtures. The analysis was verified by experimental results for both air and helium atmospheres and matches these data to within 15% over a wide range of pressures.

SiC Semiconductor Applications - An Air Force Perspective

1996 ◽  
Vol 423 ◽  
Author(s):  
L. S. Rea
Keyword(s):  
Air Force ◽  
Device Performance ◽  
Full Potential ◽  
Materials Development ◽  
Device Development ◽  
Performance Requirements ◽  
Wide Range ◽  
The Status ◽  
Performance Results ◽  
High Temperature Electronic

AbstractThe Department of Defense (DoD) is investing in the development of Silicon Carbide (SiC) for a wide range of applications. Over the past year, SiC technology has demonstrated excellent device performance results for power devices, high temperature electronic devices and microwave devices. The materials growth and processing technology for SiC is now at a level of sufficient maturity to support substantial device development efforts. While there is still considerable materials and device research required for SiC to achieve it's full potential, the fundamental technology has been proven for several critical applications. A perspective on some Air Force device performance requirements will be presented. The status of SiC materials development, material limits to advances in device performance and issues relating to supporting technology will also be discussed.

Interface Circuits for Capacitive MEMS Gyroscopes

MEMS ◽  
2017 ◽  
pp. 161-181
Author(s):  
Hongzhi Sun ◽  
Huikai Xie
Keyword(s):  
Interface Circuits ◽  
Mems Gyroscopes ◽  
Capacitive Mems

scholarly journals Multi-model forecasts of the ongoing Ebola epidemic in the Democratic Republic of Congo, March–October 2019

2020 ◽  
Vol 17 (169) ◽  
pp. 20200447
Author(s):  
Kimberlyn Roosa ◽  
Amna Tariq ◽  
Ping Yan ◽  
James M. Hyman ◽  
Gerardo Chowell
Keyword(s):  
Real Time ◽  
Dynamic Models ◽  
Democratic Republic ◽  
Democratic Republic Of Congo ◽  
Epidemiological Data ◽  
World Health ◽  
Logistic Growth ◽  
Richards Model ◽  
Wide Range ◽  
Model Approach

The 2018–2020 Ebola outbreak in the Democratic Republic of the Congo is the first to occur in an armed conflict zone. The resulting impact on population movement, treatment centres and surveillance has created an unprecedented challenge for real-time epidemic forecasting. Most standard mathematical models cannot capture the observed incidence trajectory when it deviates from a traditional epidemic logistic curve. We fit seven dynamic models of increasing complexity to the incidence data published in the World Health Organization Situation Reports, after adjusting for reporting delays. These models include a simple logistic model, a Richards model, an endemic Richards model, a double logistic growth model, a multi-model approach and two sub-epidemic models. We analyse model fit to the data and compare real-time forecasts throughout the ongoing epidemic across 29 weeks from 11 March to 23 September 2019. We observe that the modest extensions presented allow for capturing a wide range of epidemic behaviour. The multi-model approach yields the most reliable forecasts on average for this application, and the presented extensions improve model flexibility and forecasting accuracy, even in the context of limited epidemiological data.

scholarly journals Design and Analysis of a High-Gain and Robust Multi-DOF Electro-thermally Actuated MEMS Gyroscope

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 577 ◽  
Author(s):  
Muhammad Saqib ◽  
Muhammad Mubasher Saleem ◽  
Naveed Mazhar ◽  
Saif Awan ◽  
Umar Shahbaz Khan
Keyword(s):  
Resonant Frequency ◽  
Analytical Model ◽  
Actuation Voltage ◽  
High Gain ◽  
Sense Mode ◽  
Drive Mode ◽  
Mass System ◽  
Mems Gyroscope ◽  
Flat Region ◽  
Thermally Actuated

This paper presents the design and analysis of a multi degree of freedom (DOF) electro-thermally actuated non-resonant MEMS gyroscope with a 3-DOF drive mode and 1-DOF sense mode system. The 3-DOF drive mode system consists of three masses coupled together using suspension beams. The 1-DOF system consists of a single mass whose motion is decoupled from the drive mode using a decoupling frame. The gyroscope is designed to be operated in the flat region between the first two resonant peaks in drive mode, thus minimizing the effect of environmental and fabrication process variations on device performance. The high gain in the flat operational region is achieved by tuning the suspension beams stiffness. A detailed analytical model, considering the dynamics of both the electro-thermal actuator and multi-mass system, is developed. A parametric optimization is carried out, considering the microfabrication process constraints of the Metal Multi-User MEMS Processes (MetalMUMPs), to achieve high gain. The stiffness of suspension beams is optimized such that the sense mode resonant frequency lies in the flat region between the first two resonant peaks in the drive mode. The results acquired through the developed analytical model are verified with the help of 3D finite element method (FEM)-based simulations. The first three resonant frequencies in the drive mode are designed to be 2.51 kHz, 3.68 kHz, and 5.77 kHz, respectively. The sense mode resonant frequency is designed to be 3.13 kHz. At an actuation voltage of 0.2 V, the dynamically amplified drive mode gain in the sense mass is obtained to be 18.6 µm. With this gain, a capacitive change of 28.11   f F and 862.13   f F is achieved corresponding to the sense mode amplitude of 0.15   μ m and 4.5   μ m at atmospheric air pressure and in a vacuum, respectively.

scholarly journals Amplitude control system of drive-mode oscillations of MEMS gyroscopes

2019 ◽  
Vol 516 ◽  
pp. 012009
Author(s):  
T G Nesterenko ◽  
E S Barbin ◽  
P F Baranov ◽  
Lo Van Hao
Keyword(s):  
Control System ◽  
Drive Mode ◽  
Amplitude Control ◽  
Mems Gyroscopes

Decoupled Quadrature and Force Feedback Control of Capacitive MEMS Gyroscopes*

2011 ◽  
Vol 44 (1) ◽  
pp. 13534-13539 ◽  
Author(s):  
Markus Egretzberger ◽  
Florian Mair ◽  
Andreas Kugi
Keyword(s):  
Feedback Control ◽  
Force Feedback ◽  
Mems Gyroscopes ◽  
Capacitive Mems

scholarly journals Analysis of Bankruptcy Threat for Risk Management Purposes: A Model Approach

2018 ◽  
Vol 6 (4) ◽  
pp. 98
Author(s):  
Monika Wieczorek-Kosmala ◽  
Joanna Błach ◽  
Joanna Trzęsiok
Keyword(s):  
Risk Management ◽  
Liquidity Constraints ◽  
Capacity Constraints ◽  
Two Dimensions ◽  
Risk Map ◽  
Bankruptcy Costs ◽  
Debt Capacity ◽  
The Impact ◽  
Effective Design ◽  
Model Approach

In previous works, the importance of risk management implementation was addressed with regard to the problem of bankruptcy threat, with the explanation of risk impact on higher bankruptcy costs or the underinvestment problem. However, the evaluation of the impact of risk outcomes is technically linked to risk frequency and risk severity as the two dimensions of the risk map. The purpose of our study is to advocate two additional dimensions that incorporate liquidity and/or debt capacity constraint in the aftermath of risk occurrence. In the conceptual dimension, we propose a model that may support the appropriate design of risk management methods, by scaling a company’s ability to self-resist the risk outcomes. The study provides the empirical illustration of the frequency of the distinguished patterns of risk self-resistance. It was found that most frequently companies face the limited ability to self-resist risk outcomes, due to high debt capacity and high liquidity constraints. We also found statistically significant interdependencies between the company’s sector and the risk self-resistance. It supports the conclusion that the level of liquidity and debt capacity constraints and thus the ability to retain risk outcomes is sector-specific. It has important implications for the effective design of risk management methods.

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