scholarly journals Design of freeform geometries in a MEMS accelerometer with a mechanical motion preamplifier based on a genetic algorithm

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Chen Wang ◽  
Xiaoxiao Song ◽  
Weidong Fang ◽  
Fang Chen ◽  
Ioannis Zeimpekis ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Degrees Of Freedom ◽  
Microelectromechanical Systems ◽  
Computation Time ◽  
High Sensitivity ◽  
Mems Devices ◽  
Mechanical Motion ◽  
Parameter Mismatch ◽  
Mems Accelerometer ◽  
Large Bandwidth

AbstractThis paper describes a novel, semiautomated design methodology based on a genetic algorithm (GA) using freeform geometries for microelectromechanical systems (MEMS) devices. The proposed method can design MEMS devices comprising freeform geometries and optimize such MEMS devices to provide high sensitivity, large bandwidth, and large fabrication tolerances. The proposed method does not require much computation time or memory. The use of freeform geometries allows more degrees of freedom in the design process, improving the diversity and performance of MEMS devices. A MEMS accelerometer comprising a mechanical motion amplifier is presented to demonstrate the effectiveness of the design approach. Experimental results show an improvement in the product of sensitivity and bandwidth by 100% and a sensitivity improvement by 141% compared to the case of a device designed with conventional orthogonal shapes. Furthermore, excellent immunities to fabrication tolerance and parameter mismatch are achieved.

scholarly journals Pedestrian Positioning Using a Double-Stacked Particle Filter in Indoor Wireless Networks

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3907 ◽  
Author(s):  
Kwangjae Sung ◽  
Hyung Kyu Lee ◽  
Hwangnam Kim
Keyword(s):  
Particle Filter ◽  
Microelectromechanical Systems ◽  
Computational Cost ◽  
Dead Reckoning ◽  
Computation Time ◽  
Multipath Fading ◽  
Indoor Environments ◽  
Mems Devices ◽  
Proposal Distribution ◽  
Localization Scheme

The indoor pedestrian positioning methods are affected by substantial bias and errors because of the use of cheap microelectromechanical systems (MEMS) devices (e.g., gyroscope and accelerometer) and the users’ movements. Moreover, because radio-frequency (RF) signal values are changed drastically due to multipath fading and obstruction, the performance of RF-based localization systems may deteriorate in practice. To deal with this problem, various indoor localization methods that integrate the positional information gained from received signal strength (RSS) fingerprinting scheme and the motion of the user inferred by dead reckoning (DR) approach via Bayes filters have been suggested to accomplish more accurate localization results indoors. Among the Bayes filters, while the particle filter (PF) can offer the most accurate positioning performance, it may require substantial computation time due to use of many samples (particles) for high positioning accuracy. This paper introduces a pedestrian localization scheme performed on a mobile phone that leverages the RSS fingerprint-based method, dead reckoning (DR), and improved PF called a double-stacked particle filter (DSPF) in indoor environments. As a key element of our system, the DSPF algorithm is employed to correct the position of the user by fusing noisy location data gained by the RSS fingerprinting and DR schemes. By estimating the position of the user through the proposal distribution and target distribution obtained from multiple measurements, the DSPF method can offer better localization results compared to the Kalman filtering-based methods, and it can achieve competitive localization accuracy compared with PF while offering higher computational efficiency than PF. Experimental results demonstrate that the DSPF algorithm can achieve accurate and reliable localization with higher efficiency in computational cost compared with PF in indoor environments.

Piezoelectric Thin Films for Sensors, Actuators, and Energy Harvesting

MRS Bulletin ◽  
2009 ◽  
Vol 34 (9) ◽  
pp. 658-664 ◽  
Author(s):  
P. Muralt ◽  
R. G. Polcawich ◽  
S. Trolier-McKinstry
Keyword(s):  
Thin Films ◽  
Energy Harvesting ◽  
Microelectromechanical Systems ◽  
Low Voltage ◽  
High Sensitivity ◽  
Complementary Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Mems Devices ◽  
Si Substrates ◽  
The Impact

AbstractPiezoelectric microelectromechanical systems (MEMS) offer the opportunity for high-sensitivity sensors and large displacement, low-voltage actuators. In particular, recent advances in the deposition of perovskite thin films point to a generation of MEMS devices capable of large displacements at complementary metal oxide semiconductor-compatible voltage levels. Moreover, if the devices are mounted in mechanically noisy environments, they also can be used for energy harvesting. Key to all of these applications is the ability to obtain high piezoelectric coefficients and retain these coefficients throughout the microfabrication process. This article will review the impact of composition, orientation, and microstructure on the piezoelectric properties of perovskite thin films such as PbZr1−xTixO3 (PZT). Superior piezoelectric coefficients (e31, f of −18 C/m2) are achieved in {001}-oriented PbZr0.52Ti0.48O3 films with improved compositional homogeneity on Si substrates. The advent of such high piezoelectric responses in films opens up a wide variety of possible applications. A few examples of these, including low-voltage radio frequency MEMS switches and resonators, actuators for millimeter-scale robotics, droplet ejectors, energy scavengers for unattended sensors, and medical imaging transducers, will be discussed.

MEMS Accelerometer Design Optimization Using Genetic Algorithm

2013 ◽  
Vol 705 ◽  
pp. 288-294 ◽  
Author(s):  
V.S. Krushnasamy ◽  
A. Vimala Juliet
Keyword(s):  
Genetic Algorithm ◽  
Design Optimization ◽  
High Efficiency ◽  
Microelectromechanical Systems ◽  
Optimal Parameter ◽  
Low Cost ◽  
Complex Nature ◽  
Mems Accelerometer ◽  
Mems Technology ◽  
Parameter Values

MEMS (Microelectromechanical Systems) refers to the technology integrating electrical and mechanical components with feature size of 1~1000 microns. Due to its small size, low cost, low power consumption and high efficiency, MEMS technology has been widely used in many fields.In this paper,the design optimization of MEMS accelerometer is discussed.The main objective of this investigation is to find a optimum design of MEMS,which satisfies a set of given constraints. The accelerometer employs a double folded beam flexure system and the mass being displaced is the proof mass.Due to the complex nature of the problem,a genetic algorithm (GA) is developed for the optimization of MEMS.The GA attempts to minimize the die area and so the four optimal parameter values can be determined. MEMS accelerometers can be used in air-bag deployment systems in automobiles.The experimental results will show the optimal design of MEMS.

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.

Designing Thermally Actuated Bimorph as Energy Harvester

2019 ◽  
Vol 6 (1-2) ◽  
pp. 29-38
Author(s):  
Satyam Bhuyan
Keyword(s):  
Energy Harvester ◽  
Microelectromechanical Systems ◽  
Waste Heat ◽  
Piezoelectric Materials ◽  
Radiant Energy ◽  
Energy Generation ◽  
Mems Devices ◽  
Mechanical Motion ◽  
Thermally Actuated ◽  
Working Device

Abstract Microelectromechanical systems (MEMS) are micrometre-size systems that are capable of transforming electrical signals to mechanical signals. In this paper, the use of MEMS devices as a method for harvesting waste heat is explored. A background for the technology and methods is discussed and a method proposed for a working device based upon a thermally heated bimorph actuated by waste radiation alone is investigated. A chopper interrupts the radiant energy inducing an oscillation in the bimorph temperature and thus creates a mechanical motion which can be taken advantage of using piezoelectric materials. Difficulties in harvesting radiant energy with this method are highlighted and suggestions for non-passive energy generation are made based on the outlined principles.

scholarly journals Hybrid Seven-bar Press Mechanism

2018 ◽  
Vol 12 (3) ◽  
pp. 181-187
Author(s):  
M. Erkan Kütük ◽  
L. Canan Dülger
Keyword(s):  
Genetic Algorithm ◽  
Objective Function ◽  
Design Optimization ◽  
Hybrid System ◽  
Degrees Of Freedom ◽  
Dimensional Synthesis ◽  
Design Variables ◽  
Optimization Study ◽  
Metal Stamping

An optimization study with kinetostatic analysis is performed on hybrid seven-bar press mechanism. This study is based on previous studies performed on planar hybrid seven-bar linkage. Dimensional synthesis is performed, and optimum link lengths for the mechanism are found. Optimization study is performed by using genetic algorithm (GA). Genetic Algorithm Toolbox is used with Optimization Toolbox in MATLAB®. The design variables and the constraints are used during design optimization. The objective function is determined and eight precision points are used. A seven-bar linkage system with two degrees of freedom is chosen as an example. Metal stamping operation with a dwell is taken as the case study. Having completed optimization, the kinetostatic analysis is performed. All forces on the links and the crank torques are calculated on the hybrid system with the optimized link lengths

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%.

Stability of Ring-Type MEMS Gyroscopes Subjected to Stochastic Angular Speed Fluctuation

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Samuel F. Asokanthan ◽  
Soroush Arghavan ◽  
Mohamed Bognash
Keyword(s):  
Angular Velocity ◽  
Degrees Of Freedom ◽  
Microelectromechanical Systems ◽  
Damping Ratio ◽  
Operating Conditions ◽  
System Stability ◽  
System Response ◽  
Ring Type ◽  
Mems Gyroscopes ◽  
The Stability

Effect of stochastic fluctuations in angular velocity on the stability of two degrees-of-freedom ring-type microelectromechanical systems (MEMS) gyroscopes is investigated. The governing stochastic differential equations (SDEs) are discretized using the higher-order Milstein scheme in order to numerically predict the system response assuming the fluctuations to be white noise. Simulations via Euler scheme as well as a measure of largest Lyapunov exponents (LLEs) are employed for validation purposes due to lack of similar analytical or experimental data. The response of the gyroscope under different noise fluctuation magnitudes has been computed to ascertain the stability behavior of the system. External noise that affect the gyroscope dynamic behavior typically results from environment factors and the nature of the system operation can be exerted on the system at any frequency range depending on the source. Hence, a parametric study is performed to assess the noise intensity stability threshold for a number of damping ratio values. The stability investigation predicts the form of threshold fluctuation intensity dependence on damping ratio. Under typical gyroscope operating conditions, nominal input angular velocity magnitude and mass mismatch appear to have minimal influence on system stability.

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