Design Specifications for Biaxial Navigation-Grade MEMS Accelerometers

2014 ◽  
Author(s):  
Xiaowei Shan ◽  
Ting Zou ◽  
James Richard Forbes ◽  
Jorge Angeles
Keyword(s):  
Frequency Ratio ◽  
Proof Mass ◽  
Mechanical Performance ◽  
Design Parameters ◽  
Mass Motion ◽  
Mems Devices ◽  
Mems Accelerometer ◽  
Potential Market ◽  
Mems Accelerometers ◽  
Commercial Landscape

The focus of this paper is the design of a biaxial MEMS accelerometer for navigation applications. First, a survey is conducted to outline the commercial landscape of navigation-grade and MEMS accelerometers. The survey shows a potential market for navigation-grade accelerometers at the MEMS scale. Based on the specifications for navigation applications, the design targets are derived for the proposed biaxial MEMS accelerometers, including the common concerns of natural frequency ratios and bandwidth, as well as the important parameters for MEMS devices, such as hinge width, proof-mass size and mobility range. In light of the design targets, the ideal frequency matrix of the biaxial accelerometer system is derived based on the concept of generalized spring, in connection with the design targets. The stiffness values required are estimated herein. For further structural optimization, the parametric entries of the frequency-ratio matrix act as the objectives to be maximized for the lowest off-axis sensitivity of the proposed accelerometer. A suitable architecture for MEMS biaxial accelerometers is proposed thereafter. This architecture not only provides high compliance and structural isotropy for the in-plane translation, but also allows for direct measurement of the proof-mass motion. The proposed architecture is then optimized for the highest frequency ratio between the non-sensitive and sensitive axes, with regard to the design parameters and constraints. The optimization results of the proposed accelerometer demonstrate navigation-grade mechanical performance.

Design Optimization and Analysis of Proof Mass Actuation for MEMS Accelerometer: A Simulation Study

2017 ◽  
Vol 26 (06) ◽  
pp. 1750095 ◽  
Author(s):  
Vigneswaran Narayanamurthy ◽  
Sujatha Lakshminarayanan ◽  
S. Mohamed Yacin ◽  
Fahmi Samsuri
Keyword(s):  
Parallel Plate ◽  
Proof Mass ◽  
Design Parameters ◽  
Optimized Design ◽  
Efficient Design ◽  
Comb Drive ◽  
Mems Accelerometer ◽  
Mems Accelerometers ◽  
Acceleration Analysis ◽  
Cad Tool

In this paper, we present the design and analysis of the proof mass for capacitive based MEMS accelerometers. A study was done to determine the parameters (length of hinge and number of combs) to be optimized for the MEMS accelerometer design. The proposed design can measure the acceleration in [Formula: see text]-, [Formula: see text]- and [Formula: see text]-axes. The design features a proof mass with interdigitated fingers along each side. These interdigitated fingers act as parallel plate capacitors. Due to acceleration, capacitance changes along the comb drive. This change in capacitance can be used to monitor the acceleration. Analysis has been carried out with different comb width designs. Using the MEMS CAD tool CoventorWare, the structure has been designed, simulated and analyzed. The process flow for the fabrication has also been proposed for the above structure. Comparative study with several designs has been made and the efficient design parameters to be considered while designing MEMS accelerometer were proposed. Based on the study, a set of optimized design parameters for the comb accelerometer were reported.

Survivability of MEMS Accelerometer Under Sequential Thermal and High-G Mechanical Shock Environments

2015 ◽  
Author(s):  
Pradeep Lall ◽  
Amrit Abrol ◽  
Lee Simpson ◽  
Jessica Glover
Keyword(s):  
Failure Modes ◽  
Performance Enhancement ◽  
Research Work ◽  
Harsh Environments ◽  
Mechanical Shock ◽  
X Rays ◽  
Mems Devices ◽  
Mems Accelerometer ◽  
Capacitive Accelerometer ◽  
Mems Accelerometers

Reliability data on MEMS accelerometers operating in harsh environments is scarce. Micro-electro-mechanical systems (MEMS) are used in a variety of military and automotive applications for sensing acceleration, translation, rotation, pressure and sound. This research work focuses on dual axis MEMS accelerometer reliability in harsh environments. Structurally an accelerometer behaves like a damped mass on a spring. Commercially there are three types of accelerometers namely piezoelectric, piezoresistive and capacitive depending on the components that go into the fabrication of the MEMS device. Previously, majority of concentration was focused on an effective internal design, performance enhancement of CMOS-MEMS accelerometers and packaging techniques Cheng [2002], Qiao [2009], Lou [2005], and Weigold [2001]. Studies have also been conducted to obtain an enhanced inertial mass SOI MEMS process using a high sensitivity accelerometer Jianbing [2013], Chen [2005]. There have been prior test(s) conducted on MEMS accelerometers, Jiang [2004], Cao [2011], Chun-Sun [2009], Lou [2009], Tanner [2000] and Yang [2010] but the availability of data on reliability degradation of such devices in harsh environments Brown [2003] is almost little to none which thereby generates the importance of this work and also makes way for a whole new path involving the reliability assessment techniques for MEMS devices. Concentration of our work is primarily on the reliability of this accelerometer upon sequential exposure to harsh environment(s) and drop-shock. Reliability of accelerometers in high G environments is unknown. The effects of these pre-conditions along with the drop test condition has been studied and analyzed. In this piece of research work, a test vehicle with a MEMS accelerometer, ADXL278 dual axis capacitive accelerometer, has been tested under high/low temperature exposure followed by subjection to high-g and low-g shock loading environments. The test boards have been subjected to mechanical shocks using the method 2002.5, condition G, under the standard MIL-STD-883H test. The stress environment and the test condition used for this paper are 1500g and 70g respectively where 70g is the full scale range output of ADXL278 in the drop direction with pulse duration set to 0.5millisecond. The deterioration of the accelerometer output has been characterized using the techniques of Mahalanobis distance and Confidence intervals. Scanning Electron Microscopy (SEM) has been used to study the different failure modes inside of the accelerometer, which were potted and polished and later de-capped. Furthermore, the non-destructive evaluations of the MEMS accelerometer have been demonstrated through X-rays and micro-CT scans.

scholarly journals A Systematic Design Optimization Approach for Multiphysics MEMS Devices Based on Combined Computer Experiments and Gaussian Process Modelling

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7242
Author(s):  
Shayaan Saghir ◽  
Muhammad Mubasher Saleem ◽  
Amir Hamza ◽  
Kashif Riaz ◽  
Sohail Iqbal ◽  
...  
Keyword(s):  
Gaussian Process ◽  
Design Space ◽  
Microelectromechanical Systems ◽  
Computer Experiments ◽  
Design Parameters ◽  
Voltage Sensitivity ◽  
Mems Devices ◽  
Fem Simulations ◽  
Mems Accelerometer ◽  
Gradient Descent Algorithm

This paper presents a systematic and efficient design approach for the two degree-of-freedom (2-DoF) capacitive microelectromechanical systems (MEMS) accelerometer by using combined design and analysis of computer experiments (DACE) and Gaussian process (GP) modelling. Multiple output responses of the MEMS accelerometer including natural frequency, proof mass displacement, pull-in voltage, capacitance change, and Brownian noise equivalent acceleration (BNEA) are optimized simultaneously with respect to the geometric design parameters, environmental conditions, and microfabrication process constraints. The sampling design space is created using DACE based Latin hypercube sampling (LHS) technique and corresponding output responses are obtained using multiphysics coupled field electro–thermal–structural interaction based finite element method (FEM) simulations. The metamodels for the individual output responses are obtained using statistical GP analysis. The developed metamodels not only allowed to analyze the effect of individual design parameters on an output response, but to also study the interaction of the design parameters. An objective function, considering the performance requirements of the MEMS accelerometer, is defined and simultaneous multi-objective optimization of the output responses, with respect to the design parameters, is carried out by using a combined gradient descent algorithm and desirability function approach. The accuracy of the optimization prediction is validated using FEM simulations. The behavioral model of the final optimized MEMS accelerometer design is integrated with the readout electronics in the simulation environment and voltage sensitivity is obtained. The results show that the combined DACE and GP based design methodology can be an efficient technique for the design space exploration and optimization of multiphysics MEMS devices at the design phase of their development cycle.

scholarly journals Identification of Stator Winding Insulation Faults in Three-Phase Induction Motors Using MEMS Accelerometers

Proceedings ◽  
2019 ◽  
Vol 42 (1) ◽  
pp. 66
Author(s):  
Karl Schiewaldt ◽  
Guilherme Lucas ◽  
Marco Rocha ◽  
Claudio Fraga ◽  
Andre Andreoli
Keyword(s):  
Fault Diagnosis ◽  
Vibration Analysis ◽  
Induction Motors ◽  
Low Cost ◽  
Industrial Sector ◽  
Mems Devices ◽  
Mems Accelerometer ◽  
Three Phase ◽  
Special Cases ◽  
Mems Accelerometers

In recent years, the advancement of the microelectronics industry has allowed for a major expansion in the development of sensor-based equipment and applications, driven primarily by the cost reduction of micro-electro-mechanical systems (MEMS) devices. Currently, using this type of component, it is feasible to develop cost-effective systems aimed at early detection of failures in electrical machines and, in special cases, three-phase induction motors (TIM). These devices, coupled with predictive maintenance records, can prevent unexpected shutdowns due to malfunctions and signal the need for actions to extend the life cycle of the equipment. This is a relevant topic considering that the industrial sector is increasingly seeking for solutions based on non-destructive techniques (NDT) for preventive and predictive fault diagnosis. In this scenario, the objective of this work is to evaluate the application of a low-cost MEMS accelerometer to identify insulation failures in stator windings through vibration analysis. For this purpose, two MEMS accelerometers were coupled on either side of the frame of a TIM. Then, vibration signals were acquired for different types and levels of insulation failures. The data obtained were processed using different metrics such as root mean square (RMS), kurtosis, and skewness. The results allowed us to identify the insulation faults applied to the TIM, confirming the feasibility of applying the low-cost MEMS accelerometer in the vibration analysis for fault diagnosis.

scholarly journals Design and optimization of differential capacitive micro accelerometer for vibration measurement

2021 ◽  
Vol 30 (1) ◽  
pp. 19-27
Author(s):  
Kumar Gomathi ◽  
Arunachalam Balaji ◽  
Thangaraj Mrunalini
Keyword(s):  
Software Design ◽  
Proof Mass ◽  
Vibration Measurement ◽  
Design Parameters ◽  
Mechanical Sensitivity ◽  
Design And Optimization ◽  
Capacitive Accelerometer ◽  
Cross Axis ◽  
Micro Accelerometer

Abstract This paper deals with the design and optimization of a differential capacitive micro accelerometer for better displacement since other types of micro accelerometer lags in sensitivity and linearity. To overcome this problem, a capacitive area-changed technique is adopted to improve the sensitivity even in a wide acceleration range (0–100 g). The linearity is improved by designing a U-folded suspension. The movable mass of the accelerometer is designed with many fingers connected in parallel and suspended over the stationary electrodes. This arrangement gives the differential comb-type capacitive accelerometer. The area changed capacitive accelerometer is designed using Intellisuite 8.6 Software. Design parameters such as spring width and radius, length, and width of the proof mass are optimized using Minitab 17 software. Mechanical sensitivity of 0.3506 μm/g and Electrical sensitivity of 4.706 μF/g are achieved. The highest displacement of 7.899 μm is obtained with a cross-axis sensitivity of 0.47%.

scholarly journals A Low-g MEMS Accelerometer with High Sensitivity, Low Nonlinearity and Large Dynamic Range Based on Mode-Localization of 3-DoF Weakly Coupled Resonators

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 310
Author(s):  
Muhammad Mubasher Saleem ◽  
Shayaan Saghir ◽  
Syed Ali Raza Bukhari ◽  
Amir Hamza ◽  
Rana Iqtidar Shakoor ◽  
...  
Keyword(s):  
Microelectromechanical Systems ◽  
Dynamic Range ◽  
Proof Mass ◽  
Amplitude Ratio ◽  
Silicon On Insulator ◽  
Coupled Resonators ◽  
Mode Localization ◽  
Mems Accelerometer ◽  
Weakly Coupled ◽  
Input Acceleration

This paper presents a new design of microelectromechanical systems (MEMS) based low-g accelerometer utilizing mode-localization effect in the three degree-of-freedom (3-DoF) weakly coupled MEMS resonators. Two sets of the 3-DoF mechanically coupled resonators are used on either side of the single proof mass and difference in the amplitude ratio of two resonator sets is considered as an output metric for the input acceleration measurement. The proof mass is electrostatically coupled to the perturbation resonators and for the sensitivity and input dynamic range tuning of MEMS accelerometer, electrostatic electrodes are used with each resonator in two sets of 3-DoF coupled resonators. The MEMS accelerometer is designed considering the foundry process constraints of silicon-on-insulator multi-user MEMS processes (SOIMUMPs). The performance of the MEMS accelerometer is analyzed through finite-element-method (FEM) based simulations. The sensitivity of the MEMS accelerometer in terms of amplitude ratio difference is obtained as 10.61/g for an input acceleration range of ±2 g with thermomechanical noise based resolution of 0.22 and nonlinearity less than 0.5%.

Development of Photocatalytic Pervious Concrete Pavement for Air and Storm Water Improvements

2012 ◽  
Vol 2290 (1) ◽  
pp. 161-167 ◽  
Author(s):  
Somayeh Asadi ◽  
Marwa M. Hassan ◽  
John T. Kevern ◽  
Tyson D. Rupnow
Keyword(s):  
Flow Rate ◽  
Mechanical Performance ◽  
Concrete Pavement ◽  
Pervious Concrete ◽  
Mix Design ◽  
Unit Weight ◽  
Experimental Program ◽  
Design Parameters ◽  
Operational Parameters ◽  
Cleaning Agents

Self-cleaning, air-purifying pervious concrete pavement is a promising technology that can be constructed with air-cleaning agents with superhydrophilic photocatalyst capabilities, such as titanium dioxide. Although this technology has the potential of supporting environment-friendly road infrastructure, its effectiveness depends on a number of design and operational parameters that need to be evaluated. The objective of this study was to evaluate the mechanical, environmental, and mix design parameters that influence the performance and effectiveness of photocatalytic pervious concrete pavement. To achieve this objective, an experimental program was conducted in which the effects of relative humidity level, pollutants' flow rate, and mix design parameters, including void ratio and depth of the photocatalytic layer, were investigated. Mechanical performance tests included porosity, unit weight, permeability, and compressive strength. The environmental efficiency of the samples to remove nitrogen oxides (NOx) from the atmosphere was measured in the laboratory. Results of the experimental program showed that increasing the depth of the photocatalytic layer increased NOx reduction efficiency. In addition, NOx removal efficiency decreased with the increase in the pollutant flow rate and increased with the increase in ultraviolet light intensity.

A Preliminary Study on the Mechanical Performance of Tiled Polymer Composites

2006 ◽  
Author(s):  
M. A. Qidwai ◽  
J. N. Baucom ◽  
A. C. Leung ◽  
J. P. Thomas
Keyword(s):  
Composite Laminates ◽  
Load Transfer ◽  
Mechanical Performance ◽  
Local Stress ◽  
Superior Performance ◽  
Design Parameters ◽  
Interlaminar Stresses ◽  
Stress Concentrations ◽  
Critical Design ◽  
Composite Joint

We are developing and exploring the concept of in-plane tiling of composite laminates, called MOSAIC, to mitigate or control delamination at free edges due to interlaminar stresses. Initial mechanical testing has shown that MOSAIC composites with uniaxial graphite-fiber reinforced tiles retain the stiffness levels of traditional uniaxially reinforced composites but with reduced strength. The reduction in strength is attributed to the formation of resin-rich pockets between adjacent tiles. In this study, we have performed detailed finite element analyses to identify the critical design parameters that affect the mechanical performance of uniaxially reinforced MOSAIC composites. We have found that using continuous laminae on the outer surfaces significantly increases the overall loadcarrying capacity. Increasing aspect ratio of the pocket and decreasing material property differences between resin and tiles also cause better load transfer between tiles but may not necessarily improve overall strength due to increasing stress concentration. The tiling scheme and density of pocket placement influence the interaction of local stress concentrations. Consequently, a novel composite joint is proposed and found to have superior performance.

Identification of Vibration Parameters of Mechanical System Utilizing Low-Cost MEMS Accelerometers

2019 ◽  
Vol 894 ◽  
pp. 1-8
Author(s):  
Khanh Duong Quang ◽  
Huong Vuong Thi ◽  
Anh Luu Van
Keyword(s):  
High Speed ◽  
Low Cost ◽  
Damping Ratio ◽  
Vibration Reduction ◽  
Mechanical Systems ◽  
Micro Electro Mechanical Systems ◽  
Mems Accelerometer ◽  
System Parameters ◽  
Mems Accelerometers ◽  
Vibration Parameters

Multi-axial mechanical systems commonly encounter the problem of vibration while attempting to drive machining systems at high speed. Many effective methods based on feed-forward and feedback control have been proposed and applied for vibration reduction. In order to design controllers all methods require the exact knowledge of system parameters: vibration frequency and damping ratio. In recent years, low-cost Micro Electro Mechanical Systems (MEMS) accelerometers have been used for many applications in industry. This paper presents the advantage of low cost MEMS accelerometer to identify vibration parameters of mechanical systems in comparison to conventional expensive devices.

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