scholarly journals A Novel Micromachined Z-axis Torsional Accelerometer Based on the Tunneling Magnetoresistive Effect

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 422
Author(s):  
Bo Yang ◽  
Xiaoyong Gao ◽  
Cheng Li
Keyword(s):  
Magnetic Field ◽  
Magnetic Film ◽  
Theoretical Formula ◽  
Main Structure ◽  
Element Simulation ◽  
Magnetoresistive Sensors ◽  
Loop Detection ◽  
Maximal Sensitivity ◽  
The Magnetic Field ◽  
Magnetoresistive Effect

A novel micromachined z-axis torsional accelerometer based on the tunneling magnetoresistive effect is presented in this paper. The plane main structure bonded with permanent magnetic film is driven to twist under the action of inertial acceleration, which results in the opposite variation of the magnetic field intensity. The variation of the magnetic field is measured by two differential tunneling magnetoresistive sensors arranged on the top substrate respectively. Electrostatic feedback electrodes plated on the bottom substrate are used to revert the plane main structure to an equilibrium state and realize the closed-loop detection of acceleration. A modal simulation of the micromachined z-axis tunneling magnetoresistive accelerometer was implemented to verify the theoretical formula and the structural optimization. Simultaneously, the characteristics of the magnetic field were analyzed to optimize the layout of the tunneling magnetoresistance accelerometer by finite element simulation. The plane main structure, fabricated with the process of standard deep dry silicon on glass (DDSOG), had dimensions of 8000 μm (length) × 8000 μm (width) × 120μm (height). A prototype of the micromachined z-axis tunneling magnetoresistive accelerometer was produced by micro-assembly of the plane main structure with the tunneling magnetoresistive sensors. The experiment results demonstrate that the prototype has a maximal sensitivity of 1.7 mV/g and an acceleration resolution of 128 μg/Hz0.5 along the z-axis sensitive direction.

scholarly journals Design of a Micromachined Z-axis Tunneling Magnetoresistive Accelerometer with Electrostatic Force Feedback

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 158 ◽  
Author(s):  
Bo Yang ◽  
Binlong Wang ◽  
Hongyu Yan ◽  
Xiaoyong Gao
Keyword(s):  
Magnetic Field ◽  
Force Feedback ◽  
Electrostatic Force ◽  
High Sensitivity ◽  
Magnetic Films ◽  
Magnetic Film ◽  
Field Variation ◽  
Middle Plane ◽  
Main Structure ◽  
Magnetoresistive Sensors

This paper presents the design, simulation, fabrication and experiments of a micromachined z-axis tunneling magnetoresistive accelerometer with electrostatic force feedback. The tunneling magnetoresistive accelerometer consists of two upper differential tunneling magnetoresistive sensors, a middle plane main structure with permanent magnetic films and lower electrostatic feedback electrodes. A pair of lever-driven differential proof masses in the middle plane main structure is used for sensitiveness to acceleration and closed-loop feedback control. The tunneling magnetoresistive effect with high sensitivity is adopted to measure magnetic field variation caused by input acceleration. The structural mode and mass ratio between inner and outer proof masses are optimized by the Ansys simulation. Simultaneously, the magnetic field characteristic simulation is implemented to analyze the effect of the location of tunneling magnetoresistive sensors, magnetic field intensity, and the dimension of permanent magnetic film on magnetic field sensitivity, which is beneficial for the achievement of maximum sensitivity. The micromachined z-axis tunneling magnetoresistive accelerometer fabricated by the standard deep dry silicon on glass (DDSOG) process has a device dimension of 6400 μm (length) × 6400 μm (width) × 120 μm (height). The experimental results demonstrate the prototype has a maximal sensitivity of 8.85 mV/g along the z-axis sensitive direction under the gap of 1 mm. Simultaneously, Allan variance analysis illustrate that a noise floor of 86.2 μg/Hz0.5 is implemented in the z-axis tunneling magnetoresistive accelerometer.

scholarly journals DEPENDENCE OF MAXIMAL SENSITIVITY OF THE MAGNETIC FIELD HALL SENSORS BASED ON GRAPHENE ON TEMPERATURE

2021 ◽  
Vol 18 (3) ◽  
pp. 29-37
Author(s):  
І. Bolshakova ◽  
М. Strikha ◽  
Ya. Kost ◽  
F. Shurygin ◽  
Yu. Mykhashchuk ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Experimental Studies ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Thermally Induced ◽  
Temperature Range ◽  
Layer Graphene ◽  
Maximal Sensitivity ◽  
Hall Sensors ◽  
The Magnetic Field

A theory of graphene-based magnetic field Hall sensors sensitivity dependence on temperature is summarized. The existence of low-temperature range with sensitivity, almost independent on temperature, is predicted; at higher temperatures, when thermally-induced carrier concentration in graphene prevails, the sensitivity decreases with temperature. The experimental studies of the temperature dependence of magnetic sensitivity of Hall sensors on single layer graphene base were carried in temperature range from 300 °K to 430 °K. The values of sensitivity, obtained for room temperatures ~ 230 V·А‑1·Т‑1 exceed essentially the maximum sensitivity of the traditional Hall sensors on silicon base ~ 100  V·А‑1·Т‑1.

scholarly journals Гигантский магниторезистивный эффект в отражении микроволн от сверхрешеток (CoFe)/Cu

2021 ◽  
Vol 91 (2) ◽  
pp. 308
Author(s):  
А.Б. Ринкевич ◽  
Е.А. Кузнецов ◽  
Д.В. Перов ◽  
М.А. Миляев
Keyword(s):  
Magnetic Field ◽  
Reflection Coefficient ◽  
Field Dependence ◽  
Giant Magnetoresistance ◽  
Magnetic Field Dependence ◽  
Wave Reflection ◽  
Frequency Range ◽  
Giant Magnetoresistive Effect ◽  
The Magnetic Field ◽  
Magnetoresistive Effect

Experimental study of microwave giant magnetoresistive effect in wave reflection has been carried out in frequency range from 26 to 38 GHz. The magnitude of the effect is obtained and its magnetic field dependence is defined. The experiments are carried out with (CoFe)/Cu superlattices, which have giant magnetoresistance. Calculations of the magnetic field dependence of microwave reflection coefficient are fulfilled. The measured values of reflection coefficient variations are found to be greater than the calculated ones. This difference is connected with approximation within which the superlattice is replaced by the uniform metallic plate in calculations. A frequency dependence of microwave giant magnetoresistive effect in reflection is also observed. This dependence is explained by the influence of the waveguide impedance where the sample is placed in measurements.

Nonlinear Magnetostrictive Effect of Magnetorheological Elastomers

2013 ◽  
Vol 833 ◽  
pp. 291-294 ◽  
Author(s):  
Shu Lei Sun ◽  
Xiong Qi Peng ◽  
Zao Yang Guo
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Finite Element ◽  
Volume Fraction ◽  
Nonlinear Function ◽  
Measured Data ◽  
Magnetorheological Elastomers ◽  
Smart Composites ◽  
Element Simulation ◽  
The Magnetic Field

Magnetorheological elastomers (MREs) are a class of smart composites whose mechanical properties can be obviously changed under different magnetic field. Only a few works study its magnetostrictive property, which describes the changes in dimensions of a material in its magnetization. Magnetostriction in the ferromagnetic particle is also called eigenstrain in MREs. It is modeled using the nonlinear function of the magnetization in this article. The eigenstrain due to the magnetostriction is incorporated in the structure of the MREs using a generalized Hookes Law. By means of initial strain, a finite element simulation is presented to describe the magnetostriction of MREs. The results show that the magnetostriction along the magnetic field depends on the magnetization and the volume fraction of particles. As an application, we will present numerical simulations for a magnetostriction and compare these results with measured data.

Anisotropic magnetoresistive sensors of the magnetic field and current

2009 ◽  
Vol 70 (6) ◽  
pp. 1043-1053 ◽  
Author(s):  
S. I. Kasatkin ◽  
A. M. Murav’ev ◽  
N. V. Plotnikova ◽  
V. V. Amelichev ◽  
A. I. Galushkov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetoresistive Sensors ◽  
The Magnetic Field

scholarly journals Theoretical Computational Model for Cylindrical Permanent Magnet Coupling

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 2026
Author(s):  
Ke Sun ◽  
Jianwen Shi ◽  
Wei Cui ◽  
Guoying Meng
Keyword(s):  
Magnetic Field ◽  
Computational Model ◽  
Permanent Magnet ◽  
Test Bench ◽  
Magnetic Circuit ◽  
Element Simulation ◽  
Current Characteristics ◽  
Induce Eddy Current ◽  
Air Gap Magnetic Field ◽  
The Magnetic Field

Permanent magnet coupling is extensively studied owing to its economic efficiency and stability. In this study, a computational model for cylindrical permanent magnet coupling (CPMC) was designed using the magnetic field division method to divide an air gap magnetic field. An equivalent magnetic circuit model was also designed based on the equivalent magnetic circuit method. The novelty of this study is that both the skin effect and the working point of the permanent magnet are taken into consideration to obtain the magnetic circuit and induce eddy current characteristics of permanent magnet coupling. Furthermore, a computational model was obtained for the transmission torque of the CPMC based on the principles of Faraday’s and Ampere’s laws. Additionally, the accuracy of the model was verified using a finite element simulation model and a test bench.

scholarly journals Modelling of magnetic field and flux in objects having surface-hardening and transition layer

2018 ◽  
Vol 224 ◽  
pp. 03015
Author(s):  
Vladimir Kostin ◽  
Olga Vasilenko ◽  
Alexander Byzov
Keyword(s):  
Magnetic Field ◽  
Surface Layer ◽  
Transition Layer ◽  
Surface Hardening ◽  
Layer Structure ◽  
Hardened Layer ◽  
Element Simulation ◽  
Object Of Control ◽  
The Magnetic Field ◽  
Hardened Surface

A finite element simulation of the distribution of the magnetic field and flux in locally magnetized steel objects subjected to surface hardening and having after hardening a three-layer structure: a hardened surface layer, a transition layer, an unstressed core; has been conducted. Magnetization of the tested object was conducted using a U-shaped electromagnet. As a result, pictures of the distribution of the magnetic field in the monitoring object were obtained. The values of induction depending on the depth of the hardened layer for a fixed transition layer at different points of space relative to the surface of the object of control are obtained.

The Study of a MEMS Magnetic Field Sensor Based on “Cross-Shape” Ferromagnetic Film

2011 ◽  
Vol 694 ◽  
pp. 523-527 ◽  
Author(s):  
Qi Bin Lin ◽  
Guang Tao Du
Keyword(s):  
Magnetic Field ◽  
Low Cost ◽  
Ferromagnetic Film ◽  
Wheatstone Bridge ◽  
Diaphragm Thickness ◽  
Magnetic Field Sensors ◽  
Sensor Performance ◽  
Element Simulation ◽  
Field Sensor ◽  
The Magnetic Field

Novel magnetic field sensors are based on a “cross-shape” ferromagnetic film (FMF) attached to a silicon diaphragm and piezoresistive membrane. The interaction between the magnetic field and the (FMF) generates a deflection of the diaphragm, which changes the piezoresistance and unbalances a Wheatstone bridge. The effect of FMF and silicon diaphragm thickness on the sensor performance is studied by the finite element simulation. The performance of sensor can be improved by optimizing the size of “cross-shape” FMF. These low-cost, low-power sensors are easily integrated with electronic circuits.

scholarly journals The Application of a CMR-B-Scalar Sensor for the Investigation of the Electromagnetic Acceleration of Type II Superconductors

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1293
Author(s):  
Vilius Vertelis ◽  
Saulius Balevicius ◽  
Voitech Stankevic ◽  
Nerija Zurauskiene ◽  
Markus Schneider
Keyword(s):  
Magnetic Field ◽  
Field Measurements ◽  
Absolute Magnitude ◽  
Electromagnetic Properties ◽  
Type Ii ◽  
Pancake Coil ◽  
Element Simulation ◽  
Normal Metals ◽  
Numerical Finite Element ◽  
The Magnetic Field

In this paper, we investigated the behavior of a type II superconducting armature when accelerated by a pulsed magnetic field generated by a single-stage pancake coil. While conducting this investigation, we performed a numerical finite element simulation and an experimental study of the magnetic field dynamics at the edge of the pancake coil when the payload was a superconducting disc made from YBa2Cu3O7−x, cooled down to 77 K. The magnetic field measurements were performed using a CMR-B-scalar sensor, which was able to measure the absolute magnitude of the magnetic field and was specifically manufactured in order to increase the sensor’s sensitivity up to 500 mT. It was obtained that type II superconducting armatures can outperform normal metals when the launch conditions are tailored to their electromagnetic properties.

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