scholarly journals Design Optimization of Bulk Piezoelectric Acceleration Sensor for Enhanced Performance

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3360 ◽  
Author(s):  
Min-Ku Lee ◽  
Seung-Ho Han ◽  
Kyu-Hyun Park ◽  
Jin-Ju Park ◽  
Whung-Whoe Kim ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Opposite Effect ◽  
Acceleration Sensor ◽  
Electric Voltage ◽  
Design Variables ◽  
Simulation Based ◽  
Inner Diameter ◽  
Design Characteristics ◽  
Positive Effect ◽  
Piezoelectric Acceleration

While seeking to achieve high performances of a bulk piezoelectric acceleration sensor, we investigated the behavior of the design variables of the sensor components and optimized the sensor design using a numerical simulation based on piezoelectric analysis and metamodeling. The optimized results demonstrated that there was an exponential dependency in the trade-off relation between two performance indicators, the electric voltage and the resonant frequency, as induced by the design characteristics of the sensor. Among the design variables, a decrease in the base height and epoxy thickness and an increase in the piezo element’s inner diameter had a positive effect on two performances, while the head dimensions (diameter and height) exhibited the opposite effect on them. The optimal sensor designs are proposed within the valid range of resonant frequency (25–47.5 kHz). Our redesign of a commercial reference sensor improved the resonant frequency by 13.2% and the electric voltage by 46.1%.

scholarly journals A Theoretical and Empirical Investigation of Design Characteristics in a Pb(Zr,Ti)O3-Based Piezoelectric Accelerometer

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3545
Author(s):  
Min-Ku Lee ◽  
Seung-Ho Han ◽  
Jin-Ju Park ◽  
Gyoung-Ja Lee
Keyword(s):  
Resonant Frequency ◽  
Empirical Investigation ◽  
Impedance Measurement ◽  
Inverse Relation ◽  
Electric Voltage ◽  
Trade Off ◽  
Piezoelectric Accelerometer ◽  
Design Variables ◽  
Design Characteristics ◽  
The Relationship

A theoretical and experimental study on the design-to-performance characteristics of a compression-mode Pb(Zr,Ti)O3-based piezoelectric accelerometer is presented. Using the metamodeling to approximate the relationship between the design variables and the performances, the constituent components were optimized so that the generated electric voltage, representing sensitivity, could be maximized at different set values of the resonant frequency (25–40 kHz). Four kinds of optimized designs were created and fabricated into the accelerometer modules for empirical validation. The accelerometer modules fabricated according to the optimized designs were highly reliable with a broad range of resonant frequency as well as sufficiently high values of charge sensitivity. The fixed (or mounted) resonant frequency was between 16.1–30.1 kHz based on the impedance measurement. The charge sensitivity decreased from 296.8 to 79.4 pC/g with an increase of the resonant frequency, showing an inverse relation with respect to the resonant frequency. The design-dependent behaviors of the sensitivity and resonant frequency were almost identical in both numerical analysis and experimental investigation. This work shows that the piezoelectric accelerometer can be selectively prepared with best outcomes according to the requirements for the sensitivity and resonant frequency, fundamentally associated with trade-off relation.

Study on a Novel MEMS High G Acceleration Sensor

2012 ◽  
Vol 490-495 ◽  
pp. 499-503
Author(s):  
Ping Li ◽  
Yun Bo Shi ◽  
Jun Liu ◽  
Shi Qiao Gao
Keyword(s):  
Resonant Frequency ◽  
Natural Frequency ◽  
Impact Load ◽  
Hopkinson Bar ◽  
Experimental Results ◽  
Structure Parameters ◽  
Acceleration Sensor ◽  
Piezoresistive Effect ◽  
Sensor Structure ◽  
The Impact

This paper presents a novel MEMS high g acceleration sensor based on piezoresistive effect. For the designed sensor structure, the formula of stress, natural frequency and damping was derived in theory, and the resonant frequency can up to 500kHz. After the structure parameters were designed, the sensor was fabricated by the standard processing technology, and the sensitivity was tested by Hopkinson bar. According to the experimental results, the sensitivity of the high g acceleration sensor is 0.125μV/g at the impact load of 164,002g.

scholarly journals Trust in China? The impact of development, inequality, and openness on political trust across China’s provinces, 2001–2012

2016 ◽  
Vol 2 (2) ◽  
pp. 176-195 ◽  
Author(s):  
Marc L Hutchison ◽  
Ping Xu
Keyword(s):  
Opposite Effect ◽  
Political Trust ◽  
Chinese Government ◽  
World Value Survey ◽  
Important Indicator ◽  
Individual Level ◽  
Modeling Techniques ◽  
The Impact ◽  
Positive Effect ◽  
Province Level

China has long represented a puzzle for scholars of democracy, who view political trust as an important indicator of regime legitimacy. Previous studies show that while democracies around the world experienced declining levels of political trust, the authoritarian Chinese government maintained unexpectedly high levels of trust. Using World Value Survey (WVS) data over a critical 12-year period (2001–2012) and multilevel modeling techniques, we explore both macro- and individual-level determinants of political trust in China. We find that province-level economic performance and individual-level income combine to influence political trust. Higher levels of individual-level income have a positive effect on trust in more developed provinces but an opposite effect in less developed provinces. Furthermore, individuals living in provinces with higher levels of inequality and openness tend to be less trusting of government. Our study offers critical insights not only for political trust in China but also the country’s political future.

scholarly journals Characteristics Research of a High Sensitivity Piezoelectric MOSFET Acceleration Sensor

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4988
Author(s):  
Chunpeng Ai ◽  
Xiaofeng Zhao ◽  
Dianzhong Wen
Keyword(s):  
High Sensitivity ◽  
Oxide Semiconductor ◽  
Voltage Sensitivity ◽  
Test Results ◽  
Acceleration Sensor ◽  
Piezoelectric Beam ◽  
Silicon Cantilever ◽  
Gate Control ◽  
Piezoelectric Acceleration ◽  
Peak Value

In order to improve the output sensitivity of the piezoelectric acceleration sensor, this paper proposed a high sensitivity acceleration sensor based on a piezoelectric metal oxide semiconductor field effect transistor (MOSFET). It is constituted by a piezoelectric beam and an N-channel depletion MOSFET. A silicon cantilever beam with Pt/ZnO/Pt/Ti multilayer structure is used as a piezoelectric beam. Based on the piezoelectric effect, the piezoelectric beam generates charges when it is subjected to acceleration. Due to the large input impedance of the MOSFET, the charge generated by the piezoelectric beam can be used as a gate control signal to achieve the purpose of converting the output charge of the piezoelectric beam into current. The test results show that when the external excitation acceleration increases from 0.2 g to 1.5 g with an increment of 0.1 g, the peak-to-peak value of the output voltage of the proposed sensors increases from 0.327 V to 2.774 V at a frequency of 1075 Hz. The voltage sensitivity of the piezoelectric beam is 0.85 V/g and that of the proposed acceleration sensor was 2.05 V/g, which is 2.41 times higher than the piezoelectric beam. The proposed sensor can effectively improve the voltage output sensitivity and can be used in the field of structural health monitoring.

A Maximum Confidence Enhancement Based Sequential Sampling Scheme for Simulation-Based Design

2013 ◽  
Author(s):  
Zequn Wang ◽  
Pingfeng Wang
Keyword(s):  
Confidence Level ◽  
Sequential Sampling ◽  
Surrogate Models ◽  
Design Sensitivity ◽  
Reliability Estimation ◽  
Sampling Scheme ◽  
Design Variables ◽  
Simulation Based Design ◽  
Simulation Based ◽  
Maximum Improvement

This paper presents a maximum confidence enhancement based sequential sampling approach for simulation-based design under uncertainty. In the proposed approach, the ordinary Kriging method is adopted to construct surrogate models for all constraints and thus Monte Carlo simulation (MCS) is able to be used to estimate reliability and its sensitivity with respect to design variables. A cumulative confidence level is defined to quantify the accuracy of reliability estimation using MCS based on the Kriging models. To improve the efficiency of proposed approach, a maximum confidence enhancement based sequential sampling scheme is developed to update the Kriging models based on the maximum improvement of the defined cumulative confidence level, in which a sample that produces the largest improvement of the cumulative confidence level is selected to update the surrogate models. Moreover, a new design sensitivity estimation approach based upon constructed Kriging models is developed to estimate the reliability sensitivity information with respect to design variables without incurring any extra function evaluations. This enables to compute smooth sensitivity values and thus greatly enhances the efficiency and robustness of the design optimization process. Two case studies are used to demonstrate the proposed methodology.

Mechanism Simulation Based on ADAMS and Structure Optimization for Automobile Punching Parts On-Line Detector

2011 ◽  
Vol 211-212 ◽  
pp. 619-623
Author(s):  
Xi Xin Rao ◽  
Kang He ◽  
He Sheng Liu
Keyword(s):  
Objective Function ◽  
Dynamic Performance ◽  
Mathematic Model ◽  
Design Parameters ◽  
Work Piece ◽  
Simulation And Optimization ◽  
Design Variables ◽  
Simulation Based ◽  
On Line ◽  
Line Detector

Camera Device is crucial components of Automobile punching parts on-line detector and Its dynamic characteristics has a critical influence on the accuracy of Automobile punching parts on-line detector. To reduce the relative acceleration of Camera Device to the measured part, biaxial body of Automobile Punching Parts On-line Detector was optimized. On the basis of analyzing mechanism, simplifying the prototype, determining the design variables and the objective function and the constraint condition, this paper puts forward the parameter optimization mathematic model with the minimum of the acceleration of Camera Device relative to the point on the measured work piece as objective function and completes mechanism simulation and optimization by the ADAMS software. The results show that some design parameters gets more reasonable and dynamic performance of Automobile punching parts on-line detector is better.

Design and Microfabrication of Terahertz Magnetic Metamaterials

2003 ◽  
Author(s):  
Ta-Jen Yen ◽  
Nicholas Fang ◽  
Xiang Zhang
Keyword(s):  
Infrared Spectroscopy ◽  
Resonant Frequency ◽  
Design Parameter ◽  
First Generation ◽  
Critical Dimension ◽  
Magnetic Response ◽  
Simulation Design ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Design Variables ◽  
Relationship Of

In this work, we introduce the simulation design and microfabrication of a class of magnetic metamaterials with critical dimension of 2–6 microns and lattice constant of 30–50 microns. These metamaterials will exhibit magnetic response at 0.5–2THz. To optimize the design variables, we conducted a series of Taguchi experiments and a quasi-linear relationship of resonant frequency is established upon each design parameter. We are currently characterizing the first generation of the fabricated magnetic metamaterials using Fourier Transformed Infrared spectroscopy.

scholarly journals Sex Differences in Intimacy Levels in Best Friendships and Romantic Partnerships

2020 ◽  
Author(s):  
Eiluned Pearce ◽  
Anna Machin ◽  
Robin I. M. Dunbar
Keyword(s):  
Romantic Relationships ◽  
Opposite Effect ◽  
Mutual Support ◽  
Term Survival ◽  
Female Relationships ◽  
Health And Wellbeing ◽  
Negative Effect ◽  
Survival And Reproduction ◽  
Best Friendships ◽  
Positive Effect

Abstract Objectives Close romantic and friendship relationships are crucial for successful survival and reproduction. Both provide emotional support that can have significant effects on an individual’s health and wellbeing, and through this their longer term survival and fitness. Nonetheless, the factors that create and maintain intimacy in close relationships remain unclear. Nor is it entirely clear what differentiates romantic relationships from friendships in these terms. In this paper, we explore which factors most strongly predict intimacy in these two kinds of relationship, and how these differ between the two sexes. Results Aside from best friendships being highly gendered in both sexes, the dynamics of these two types of relationships differ between the sexes. The intimacy of female relationships was influenced by similarity (homophily) in many more factors (notably dependability, kindness, mutual support, sense of humour) than was the case for men. Some factors had opposite effects in the two sexes: gift-giving had a negative effect on women’s friendships and a positive effect on men’s, whereas shared histories had the opposite effect. Conclusion These results confirm and extend previous findings that the dynamics of male and female relationships are very different in ways that may reflect differences in their functions.

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