Review of Helical Magnetic Structures in Magnetic Microwires

We provide an overview of the helical magnetic structures in magnetic microwires. Having analyzed the experimental data describing the magnetic behavior of magnetic microwires since the 1990s, we found indirect evidence of the existence of various types of helical magnetic structures. Purposeful research has allowed us to discover the spiral magnetic structure as one of the most unusual helical structures. A comparison of the spiral structure with another type of helical structure—elliptical—was carried out. In the analysis, emphasis was placed on the length of the domain wall as one of the most important parameters. The difference in the dynamic properties of the spiral and elliptical domain walls has been demonstrated.This research was funded by the Spanish MCIU, under PGC2018-099530-B-C31 (MCIU/AEI/FEDER, UE), by the EU under the “INFINITE”(Horizon 2020) project, by the Government of the Basque Country, under the PUE_2021_1_0009 and Elkartek (MINERVA, ZE-KONP and COMPONENS) projects, by the University of the Basque Country, under the scheme of “Ayuda a Grupos Consolidados” (Ref.: GIU18/192) and under the COLAB20/15 project and by the Diputación Foral de Gipuzkoa in the frame of Programa “Red guipuzcoana de Ciencia, Tecnología e Innovación 2021” under the 2021-CIEN-000007-01 project

A Novel Variable Geometry based Planar Inductor Design for Wireless Charging Application

In this thesis, the performance, modelling and application of a planar electromagnetic coil are discussed. Due to the small size profiles and their non‐contact nature, planar coils are widely used due to their simple and basic design. The uncertain parameters have been identified and simulated using ANSYS that has been run utilising a newly developed MATLAB code. This code has made it possible to run thousands of trials without the need to manually input the various parameters for each run. This has facilitated the process of obtaining all the probable solutions within the defined range of properties. The optimum and robust design properties were then determined. The thesis discusses the experimentation and the finite element modelling (FEM) performed for developing the design of planar coils and used in wireless chargers. In addition, the thesis investigates the performance of various topologies of planar coils when they are used in wireless chargers. The ANSYS Maxwell FEM package has been used to analyse the models while varying the topologies of the coils. For this purpose, different models in FEM were constructed and then tested with topologies such as circular, square and hexagon coil configurations. The described methodology is considered as an effective way for obtaining maximum Power transfer efficiency (PTE) with a certain distance on planar coils with better performance. The explored designs studies are, namely: (1) Optimization of Planar Coil Using Multi-core, (2) planar coil with an Orthogonal Flux Guide, (3) Using the Variable Geometry in a Planar coil for an Optimised Performance by using the robust design method, (4) Design and Integration of Planar coil on wireless charger. In the first design study, the aim is to present the behaviour of a newly developed planar coil, built from a Mu-metal, via simulation. The structure consists of an excitation coil, sensing coils and three ferromagnetic cores 2 located on the top, middle and bottom sections of the coil in order to concentrate the field using the iterative optimisation technique. Magnetic materials have characteristics which allows them to influence the magnetic field in its environment. The second design study presents the optimal geometry and material selection for the planar with an Orthogonal Flux Guide. The study demonstrates the optimising of the materials and geometry of the coil that provides savings in terms of material usage as well as the employed electric current to produce an equivalent magnetic field. The third design study presents the variable geometry in a planar inductor to obtain the optimised performance. The study has provided the optimum and robust design parameters in terms of different topologies such as circular, square and hexagon coil configurations and then tested, Once the best topology is chosen based on performance. The originality of the work is evident through the randomisation of the parameters using the developed MATLAB code and the optimisation of the joint performance under defined conditions. Finally, the fourth design study presents the development of the planar coil applications. Three shapes of coils are designed and experimented to calculate the inductance and the maximum power transfer efficiency (PTW) over various spacing distances and frequency

Development of a robot-based magnetic flux leakage inspection system

Surface cracking is one of the primary factors leading to failure of mechanical components. One of the most sensitive methods for surface or near surface crack detection is MFL inspection. Magnetic sensor based MFL inspection, MSI, has shown many advantageous over MPI and gives the opportunity for automated MFL inspection after its equivalent detectability to MPI is validated. A standard industrial robot is introduced and applied in this work as an automated solution for precise sensor guidance and a more accurate, flexible and efficient automatic MSI system is developed as an extension of the already existing automatic MFL inspection scheme at IZFP. Performance of the system is demonstrated by applying the system on different inspection situations of concern. The measurement results obtained validate the application of the system on the inspection.Oberflächenrisse sind eine der wichtigsten Faktoren, die zum Versagen von mechanischen Komponenten führen können. Eine der empfindlichsten Methoden für Überprüfung von Oberflächen auf Risse im Bereich der Werkstückoberfläche ist die magnetische Streuflussprüfung. Die auf dem Magnetsensor basierte magnetische Streuflussprüfung, MSI, hat viele Vorteile bei der praktischen Anwendung gegenüber MPI gezeigt und bietet die Möglichkeit zur automatisierten MFL mit dem Gegenwert der Validierung des MPI Verfahrens. In dieser Arbeit wird ein Standard-Industrieroboter vorgestellt, welcher für eine automatisierte Lösung zur Prüfungsdurchführung verwendet wird. So kann die präzise Sensorführung für ein genaues, flexibles und effizientes automatisches MSI-System gewährleistet werden. Das System dient auch als Erweiterung zu den bereits bestehenden automatischen MFL Prüfsystem besteht. Schließlich wird die Leistungsfähigkeit des Gesamtsystems durch die Anwendungen in unterschiedlichen Prüfsituationen demonstriert. Die erhaltenen Prüfergebnisse bestätigen die Anwendung des Systems als Grundlage für unterschiedliche Prüfaufgaben im mechanisierten Prüfbetrieb auch im Produktionsprozeß

Microfluidics for Biosensing and Diagnostics

Efforts to miniaturize sensing and diagnostic devices and to integrate multiple functions into one device have caused massive growth in the field of microfluidics and this integration is now recognized as an important feature of most new diagnostic approaches. These approaches have and continue to change the field of biosensing and diagnostics. In this Special Issue, we present a small collection of works describing microfluidics with applications in biosensing and diagnostics

Recent Application in Biometrics

In the recent years, a number of recognition and authentication systems based on biometric measurements have been proposed. Algorithms and sensors have been developed to acquire and process many different biometric traits. Moreover, the biometric technology is being used in novel ways, with potential commercial and practical implications to our daily activities. The key objective of the book is to provide a collection of comprehensive references on some recent theoretical development as well as novel applications in biometrics. The topics covered in this book reflect well both aspects of development. They include biometric sample quality, privacy preserving and cancellable biometrics, contactless biometrics, novel and unconventional biometrics, and the technical challenges in implementing the technology in portable devices. The book consists of 15 chapters. It is divided into four sections, namely, biometric applications on mobile platforms, cancelable biometrics, biometric encryption, and other applications. The book was reviewed by editors Dr. Jucheng Yang and Dr. Norman Poh. We deeply appreciate the efforts of our guest editors: Dr. Girija Chetty, Dr. Loris Nanni, Dr. Jianjiang Feng, Dr. Dongsun Park and Dr. Sook Yoon, as well as a number of anonymous reviewers

Fluxgate Impedanzanalysator für Empfindlichkeits- und Rauscheigenschaften

The fluxgate sensor is known as a precision, low noise, reliable magnetic field sensor, and has been developed for decades. The sensor has been used in measurement systems, which need high precision in magnetic field measurements such as in satellite systems, navigation, and geological exploration. Although there are lots of competitors to the fluxgate such as Hall, GMR, and AMR sensors, the development of fluxgate sensors is still continuing to get better performance. There are still many potential developments of fluxgate sensors, to make it better than what is nowadays commercially available. The main big potential is the development of sensitivity and noise properties. Many efforts have been done to obtain this such as treatment of the core material, tuning the coils, making a new model of output voltage involving the core permeability or coil inductance, and the electronics signal processing optimization. The new model is intended to obtain the good permeability, inductance, or any other parameters for the best sensitivity and noise performance by designing the geometry. This thesis describes the development of a novel fluxgate analyzer for fluxgate sensor characterization, which is used for modeling the fluxgate sensor output to study the parameters that affect fluxgate sensor output. The characterization is based on the impedance of fluxgate sensor coils, which contain high permeability material as fluxgate sensor core. The non-linearity of the core permeability becomes the crucial and important topic in designing the impedance analyzer. The instrument has been designed to comply with the fluxgate sensor characteristics, which has low impedance and high core permeability. For that reason, the fluxgate analyzer has been designed with low output impedance and to be able to provide a very low current for fluxgate impedance measurement. A model from the impedance measurement is used to calculate and predict the fluxgate output sensitivity. Together with other physical parameters such as winding number and length, the model is utilized to set-up an equation to calculate the fluxgate output voltage and sensitivity.Der Fluxgate-Sensor ist als präziser, rauscharmer, zuverlässiger Magnetfeldsensor bekannt, und wird seit Jahrzehnten entwickelt. Der Sensor wurde in Messsystemen verwendet, die eine hohe Präzision bei Magnetfeldmessungen erfordern, beispielsweise bei Satellitensystemen, bei der Navigation und bei der geologischen Erkundung. Obwohl für das Fluxgate viele Konkurrenten wie Hall-, GMR- und AMR-Sensoren vorhanden sind, wird die Entwicklung an Fluxgates für eine bessere Performance weiter geführt. Es gibt noch viele mögliche Entwicklungen an Fluxgate-Sensoren, um sie besser zu machen als die, die heutzutage kommerziell erhältlich sind. Das wichtigste und größte Potenzial ist die Verbesserung der Empfindlichkeits- und Rauscheigenschaften. Viele Anstrengungen wurden unternommen, um dies zu erreichen, wie eine Bearbeitung des Kernmaterials, ein Abstimmen der Spulen, ein neues Modell der Ausgangsspannung, die die Kernpermeabilität oder Spuleninduktivität beinhaltet, und die Optimierung der Elektroniksignalverarbeitung.Das neue Modell soll die gute Permeabilität, Induktivität oder andere Parameter für die beste Empfindlichkeit und Rauschleistung durch die Gestaltung der Geometrie enthalten. Diese Arbeit beschreibt die Entwicklung eines neuartigen Fluxgate-Analysators zur Fluxgate-Sensorcharakterisierung. Dieser wird zur Modellierung des Fluxgate-Sensorausgangs verwendet, um die Parameter zu untersuchen, die den Fluxgate-Sensorausgang beeinflussen. Die Charakterisierung basiert auf der Impedanz von Fluxgate-Sensorspulen, die als Fluxgate-Sensorkern hochpermeables Material enthalten. Die Nichtlinearität der Kernpermeabilität wird zum entscheidenden und wichtigen Thema beim Entwurf des Impedanzanalysators. Das Gerät wurde so entwickelt, dass es den Eigenschaften des Fluxgate-Sensors entspricht, der eine niedrige Impedanz und eine hohe Kernpermeabilität aufweist. Aus diesem Grund wurde der Fluxgate-Analysator mit einer niedrigen Ausgangsimpedanz entworfen und kann einen sehr niedrigen Strom für die Fluxgate-Impedanzmessung bereitstellen. Ein Modell aus der Impedanzmessung wird verwendet, um die Fluxgate-Ausgangsempfindlichkeit zu berechnen und vorherzusagen. Zusammen mit anderen physikalischen Parametern wie Wicklungszahlen und -länge wird das Modell verwendet, um eine Gleichung zur Berechnung der Fluxgate-Ausgangsspannung und -empfindlichkeit zu erstellen

EUROSENSORS XVII : book of abstracts

Fundação Calouste Gulbenkien (FCG).Fundação para a Ciência e a Tecnologia (FCT)

Department of Defense Dictionary of Military and Associated Terms

The Joint Publication 1-02, Department of Defense Dictionary of Military and Associated Terms sets forth standard US military and associated terminology to encompass the joint activity of the Armed Forces of the United States. These military and associated terms, together with their definitions, constitute approved Department of Defense (DOD) terminology for general use by all DOD components