scholarly journals Simulation and improvements of a magnetic flux sensor for application in immunomagnetic biosensing platforms

2021 ◽  
Author(s):  
Kan Wang ◽  
TangAn Li ◽  
Bo Cao ◽  
Hao Xu ◽  
Wei Zheng ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Limit Of Detection ◽  
Signal To Noise Ratio ◽  
Point Of Care ◽  
Test Strip ◽  
Magnetic Field Measurement ◽  
Element Analysis ◽  
Sensor Structure ◽  
Flux Sensor

In recent years, point-of-care testing (POCT) has become a topical issue. Lateral flow immunoassay strategies based on magnetic nanoparticles (MNPs) are important POCT elements due to their sensitive quantification of biological materials via MNP magnetic field measurement. In this study, we designed a magnetic flux sensor for use in immunomagnetic biosensing platforms, incorporating a mathematical model and computer simulation strategy. The system used field programmable gate array (FPGA) as the control chip, synthesized excitation signals and excited coils to generate excitation magnetic fields. Also, the stepping motor was controlled to drive the test strip at a uniform speed through the sensor detection area. A differential configuration strategy was used for sensor pick-up coils to assess MNP influence on the magnetic flux, which was insensitive to background magnetic interference and common-mode noise. These factors significantly enhanced the signal-to-noise ratio of the sensor. The magnetic flux sensor structure was optimized, and response magnetic field characteristics of MNP on test strips analyzed using finite element analysis (FEA) simulations. System performance was evaluated by testing human chorionic gonadotropin (HCG), which demonstrated a linear performance, with a limit of detection of 0.0098 mIU/mL. This system may be used to identify other target analytes in different application settings.

scholarly journals Performance Validation of a Planar Hall Resistance Biosensor through Beta-Amyloid Biomarker

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 434 ◽  
Author(s):  
SungJoon Kim ◽  
Sri Ramulu Torati ◽  
Artem Talantsev ◽  
ChangYeop Jeon ◽  
SungBae Lee ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Second Harmonic ◽  
Signal To Noise Ratio ◽  
Point Of Care ◽  
Magnetic Sensors ◽  
Hall Resistance ◽  
Field Mode ◽  
Mode Method ◽  
Performance Validation

Magnetic sensors have great potential for biomedical applications, particularly, detection of magnetically-labeled biomolecules and cells. On the basis of the advantage of the planar Hall effect sensor, which consists of improved thermal stability as compared with other magnetic sensors, we have designed a portable biosensor platform that can detect magnetic labels without applying any external magnetic field. The trilayer sensor, with a composition of Ta (5 nm)/NiFe (10 nm)/Cu (x = 0 nm~1.2 nm)/IrMn (10 nm)/Ta (5 nm), was deposited on a silicon wafer using photolithography and a sputtering system, where the optimized sensor sensitivity was 6 μV/(Oe∙mA). The detection of the magnetic label was done by comparing the signals obtained in first harmonic AC mode (1f mode) using an external magnetic field and in the second harmonic AC mode (2f mode) with a self-field generated by current passing through the sensor. In addition, a technique for the β-amyloid biomarker-based antibody-antigen sandwich model was demonstrated for the detection of a series of concentrations of magnetic labels using the self-field mode method, where the signal-to-noise ratio (SNR) was high. The generated self-field was enough to detect an immobilized magnetic tag without an additional external magnetic field. Hence, it could be possible to reduce the device size to use the point-of-care testing using a portable circuit system.

Finite Element Analysis and Research on Corrosion Defect of Tank Floor

2016 ◽  
Vol 853 ◽  
pp. 514-518
Author(s):  
Zhi Jun Yang ◽  
De Shu Chen ◽  
Liang Chen ◽  
Yu Zhuo Liu ◽  
Ran An ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Magnetic Flux ◽  
Magnetic Flux Leakage ◽  
Bottom Plate ◽  
Element Analysis ◽  
Corrosion Defect ◽  
Leakage Magnetic Field ◽  
Leakage Field ◽  
Flux Leakage

Storage tank is an essential vessel in petrochemical industry, and the corrosion of tank is an important reason for the safety hazard. The corrosion of tank bottom plate is more serious than the tank wall, and it is not easy to check and repair, when damaged to a certain extent it will cause the leakage of the media, then lead to waste of energy, environmental pollution, at the same time it will cause a major accident. Magnetic flux leakage testing is widely used in the field of tank floor inspection with the advantages of fast scanning speed, accurate results and so on. In this paper, the finite element simulation and analysis of the corrosion defect leakage magnetic field is used to obtain the data, and the characteristic of the leakage magnetic field is extracted. The effect of defect depth and width and shape on the magnetic flux leakage field is studied, and the distribution curve of the magnetic flux leakage field is obtained.

A High Accuracy of Magnetometer by Using Independent Directional Magnetic Field Measurement Technique

2014 ◽  
Vol 565 ◽  
pp. 133-137
Author(s):  
Athirot Mano ◽  
Wisut Titiroongruang
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Flux Density ◽  
Measurement Technique ◽  
Field Measurement ◽  
High Accuracy ◽  
Two Dimensions ◽  
Magnetic Flux Density ◽  
Magnetic Field Measurement ◽  
Hall Sensors

In a measurement of magnetic flux density with high accuracy by using Hall effect sensor must be considered position of Hall sensor, that perfect perpendicular with magnetic flux line for measurement. Only one Hall element can cause measuring error. Therefore, this paper presents an application of independent directional magnetic field measurement technique on two dimensions for high accuracy magnetometer. It is presented by using two Hall sensors locate perpendicular to each other and use the relation of the two voltage output signal from both Hall sensors to calculate constant Hall voltage and Magnetic flux density with high accuracy by using trigonometric function with Lab-View programming. And as the result of experiment, this technique can reduce the limitation in term of this angle in the range magnetic flux density can be measured 0-1800 gauss. A calibration curve of this system compare with standard Gauss meter shows the coefficient of determination (R2) equal to 1 and has the accuracy percentage as less than 0.5%.

Finite Element Analysis of Magnetization Reversal Effect Based on Ferromagnetic Specimens

2014 ◽  
Vol 620 ◽  
pp. 127-132
Author(s):  
Xiao Wen Xi ◽  
Shang Kun Ren ◽  
Li Hua Yuan
Keyword(s):  
Magnetic Field ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Magnetic Flux ◽  
Magnetization Reversal ◽  
Tensile Load ◽  
Magnetic Flux Leakage ◽  
Element Analysis ◽  
The Magnetic Field ◽  
Flux Leakage

Using large finite element analysis (FEA) software ANSYS, the stress-magnetization effect on 20# steel specimens with different shape notches is simulated under the geomagnetic field and tensile load. With the stimulation, the magnetic flux leakage fields at certain positions of the surface specimen were measured. Through analysis the relationship between the magnetic flux leakage fields of certain points with tensile stress, the results showed that the magnetic field value at certain positions of specimen surface first decreases and then increases along with the increase of stress, which is called magnetization reversal phenomenon; Different gaps and different positions of the specimen show different magnetization reversal rules; By measuring the maximal variation of the magnetic field value △Hmax at certain positions of the surface specimen and by analyzing its change law, we can roughly estimate specimen stress size and distribution regularity of stress. Moreover, this article also discusses the effect of lifts-off of the probe on the law of stress magnetization.

Improvement of Independent Directional Magnetic Field Measurement Technique with Hall Sensors

2013 ◽  
Vol 811 ◽  
pp. 347-352 ◽  
Author(s):  
Athirot Mano ◽  
Narin Atiwongsangthong ◽  
Wisut Titiroongruang
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Flux Density ◽  
Field Measurement ◽  
Density Measurement ◽  
Original System ◽  
Magnetic Flux Density ◽  
Magnetic Field Measurement ◽  
Hall Sensors ◽  
Flux Density Measurement

The independent directional magnetic field measurement is a new technique for magnetic flux density measurement with high accuracy. This technique can reduce the limitation in term of angle that magnetic flux lines interact with Hall sensors. However, the original system limits the uniformity and symmetry of magnetic field patterns, which can cause an error for measurement system. Therefore, the aim of this research is to present the method to increase measurement accuracy of system, by improve magnetic field uniformity which can be done by using electromagnet instead of permanent magnet. The system is also improved the mechanical circle motion by using stepping motor, it is used to rotate Hall sensors in magnetic field which is generated by electromagnet. The result from experiment has shown of this method that can reduce the error percentage as 5% compare with original system. This method is shown 0.99997 of coefficient of determination, which represents to accuracy in magnetic flux density measurement range 0-1350 Gauss.

scholarly journals Effect of Pole Shoe Design on Inclination Angle of Different Magnetic Fields in Permanent Magnet Machines

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2437
Author(s):  
Jonathan Sjölund ◽  
Sandra Eriksson
Keyword(s):  
Magnetic Field ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Field Strength ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Magnetic Circuit ◽  
Magnetic Flux Density ◽  
Element Analysis ◽  
Inclination Angles

Electromagnetic modelling of electrical machines through finite element analysis is an important design tool for detailed studies of high resolution. Through the usage of finite element analysis, one can study the electromagnetic fields for information that is often difficult to acquire in an experimental test bench. The requirement for accurate result is that the magnetic circuit is modelled in a correct way, which may be more difficult to maintain for rare earth free permanent magnets with an operating range that is more likely to be close to non-linear regions for the relation between magnetic flux density and magnetic field strength. In this paper, the inclination angles of the magnetic flux density, magnetic field strength and magnetization are studied and means to reduce the inclination angles are investigated. Both rotating and linear machines are investigated in this paper, with different current densities induced in the stator windings. By proper design of the pole shoes, one can reduce the inclination angles of the fields in the permanent magnet. By controlling the inclination angles, one can both enhance the performance of the magnetic circuit and increase the accuracy of simpler models for permanent magnet modelling.

scholarly journals Dish-Shape Magnetic Flux Concentrator for Inductive Power Transfer Systems

2020 ◽  
pp. 455-461
Author(s):  
Marwan H. Mohammed ◽  
◽  
Yasir M. Y. Ameen ◽  
Ahmed A. S. Mohamed
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Power Transmission ◽  
Three Dimensional ◽  
Transmission Efficiency ◽  
Power Transfer ◽  
Element Analysis ◽  
Inductive Power Transfer ◽  
Three Dimensional Finite Element ◽  
Inductive Power

Recently, safety concerns related to electro-magnetic fields (EMFs) in inductive power transfer (IPT) systems for electric vehicles applications are pointed out. Magnetic flux concentrators are commonly used in the system to direct magnetic field lines and enhance the power transfer capability and efficiency. This article explores the performance of an IPT system for two different shapes of magnetic flux concentrators in terms of magnetic field distribution and power transmission efficiency. The dish-shape and plate-shape flux concentrators are examined and compared with a coreless IPT system. A simulation study based on three-dimensional finite-element analysis is carried out to design the magnetic couplers and analyze the IPT system’s performance. The simulation results are verified analytically and good matches are achieved.

scholarly journals Calibration of ac induction magnetometer

2018 ◽  
Vol 31 (4) ◽  
pp. 613-626 ◽  
Author(s):  
Branko Koprivica ◽  
Marko Sucurovic ◽  
Alenka Milovanovic
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Flux Density ◽  
Field Measurement ◽  
Large Diameter ◽  
Experimental Results ◽  
Magnetic Flux Density ◽  
Magnetic Field Measurement ◽  
Experimental Setup ◽  
Coil System

The aim of this paper is to describe a procedure and experimental setup for calibration of AC induction magnetometer. The paper presents an overview of the previous research and results of measurement of magnetic flux density inside large diameter multilayer solenoid. This solenoid is magnetising coil of the magnetometer. The paper also describes a system of five smaller coils of the magnetometer which are placed inside the large solenoid. Three small coils are pickup coils, accompanied with two compensation coils, of which one is an empty coil for magnetic field measurement. The experimental results of calibration of this coil system have been presented. A proper discussion of all the results presented has been also given in the paper.

scholarly journals Ultrasensitive Magnetic Field Sensors for Biomedical Applications

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1569 ◽  
Author(s):  
Dmitry Murzin ◽  
Desmond J. Mapps ◽  
Kateryna Levada ◽  
Victor Belyaev ◽  
Alexander Omelyanchik ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Quantum Interference ◽  
Biomedical Applications ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Point Of View ◽  
Nitrogen Vacancy ◽  
Physical Point ◽  
Atomic Lattice ◽  
Magnetic Field Sensors

The development of magnetic field sensors for biomedical applications primarily focuses on equivalent magnetic noise reduction or overall design improvement in order to make them smaller and cheaper while keeping the required values of a limit of detection. One of the cutting-edge topics today is the use of magnetic field sensors for applications such as magnetocardiography, magnetotomography, magnetomyography, magnetoneurography, or their application in point-of-care devices. This introductory review focuses on modern magnetic field sensors suitable for biomedicine applications from a physical point of view and provides an overview of recent studies in this field. Types of magnetic field sensors include direct current superconducting quantum interference devices, search coil, fluxgate, magnetoelectric, giant magneto-impedance, anisotropic/giant/tunneling magnetoresistance, optically pumped, cavity optomechanical, Hall effect, magnetoelastic, spin wave interferometry, and those based on the behavior of nitrogen-vacancy centers in the atomic lattice of diamond.

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