Design of Integrated Micro-Fluxgate Magnetic Sensors: Advantages and Challenges of Numerical Analyses

Abstract

Miniaturization and on-chip integration are major lines of research in many branches of science and technology developments, undoubtedly in sensor technology. Fluxgate magnetometers are very sensitive, and accurate magnetic sensors able to detect weak fields both AC and DC, which in recent years saw a great effort in minimizing their dimensions, weight, and power consumption. The physics behind the fluxgate principle is rather complex and makes simulations difficult and only partially used in the literature. The limited physical access to micro sensors for measurements and the need to optimize the entire integrated system, including the sensor geometry and the excitation and readout circuits, make numerical analyses particularly useful in the design of miniaturized sensors. After a thorough review of the miniaturized solutions proposed so far, the present paper examines in detail the possibility of adopting a model based approach for designing miniaturized fluxgate sensors. The model of the fluxgate effect of two different technologies proposed in the literature has been implemented to benchmark simulation results with real data. In addition to the advantages for an optimized design, the implementation and computational challenges of the numerical analyses are precisely outlined.

Realization and Tests of Prototype Fluxgate Magnetic Sensors for the ITER Neutral Beam Injectors

“…The length of the winding was 16 mm. The excitation coils were fixed in parallel cylindrical holes inside the bobbin to make a Vacquier type fluxgate sensor [ 9 , 18 ].…”

“…Metallic Hall sensors can be used in these conditions, but their limited sensitivity [ 6 ] and complexity [ 7 ] would not allow their use for this specific application. MEMS sensors and magnetoresistive sensors have been considered several years ago [ 8 , 9 , 10 ] but have been abandoned due to their insufficient tolerance to radiation. Optical atomic magnetometers [ 11 ] can achieve sensitivity better than .…”

“…It is possible to overcome these difficulties using a fluxgate-type magnetometer (see Figure 2 ), since its sensing part is simple, intrinsically robust and does not require delicate semiconductor components. Moreover, it does not require offset compensation, as it intrinsically provides an absolute measurement of the magnetic induction field, whereas other types of sensors measure the value relative to a reference [ 9 , 13 ]. Other reasons for selecting a fluxgate magnetometer for the present application are the following: A fluxgate magnetometer is intrinsically directional.…”

Study and implementation of fluxgate current sensor with wireless connectivity for finger exoskeleton rehabilitation

“…Marconato 25 Dalessandro et al 16 Kashmiri et al 26 Noise density (nT/√Hz) . proportions between the phalanges decrease according to physiological constraints and typical circular grasping proportions.…”

Measurement System for Short-Pulsed Magnetic Fields

“…Depending on the area of application, such sensors can be large in size (about 50 mm for detecting cardiac activity [ 5 ]) as well as miniaturized. The miniaturized sensors are manufactured with PCB technology, allowing the construction of sensors measuring several tens of millimeters [ 6 ]. However, as the measured signal in this case is proportional to the derivative of the magnetic pulse, to obtain the real magnetic pulse shape, the signal has to be integrated.…”