Magnetic Crosstalk Suppression and Probe Miniaturization of Coupled Core Fluxgate Sensors

This paper demonstrates the probe structure optimization of coupled core fluxgate magnetic sensors through finite element analysis. The obtained modelling results have been used to optimize the probe structures from horizontal- to vertical- arrangements for magnetic crosstalk suppression and probe miniaturization. The finite element analysis show that with the same distance between each adjacent fluxgate elements, the magnetic crosstalk is suppressed by 6 times and the volume is reduced by 2 times after the optimization. Furthermore, the miniaturized probes with low magnetic crosstalk have been designed and implemented. The experimental results which showed more than 5 times suppression of magnetic crosstalk verified the simulation results. Therefore, the results provide detailed reference to cope with the contradiction between volume miniaturization and magnetic crosstalk suppression in magnetic sensor-array design

Symmetry-Breaking as a Paradigm to Design Highly-Sensitive Sensor Systems

A large class of dynamic sensors have nonlinear input-output characteristics, often corresponding to a bistable potential energy function that controls the evolution of the sensor dynamics. These sensors include magnetic field sensors, e.g., the simple fluxgate magnetometer and the superconducting quantum interference device (SQUID), ferroelectric sensors and mechanical sensors, e.g., acoustic transducers, made with piezoelectric materials. Recently, the possibilities offered by new technologies and materials in realizing miniaturized devices with improved performance have led to renewed interest in a new generation of inexpensive, compact and low-power fluxgate magnetometers and electric-field sensors. In this article, we review the analysis of an alternative approach: a symmetry-based design for highly-sensitive sensor systems. The design incorporates a network architecture that produces collective oscillations induced by the coupling topology, i.e., which sensors are coupled to each other. Under certain symmetry groups, the oscillations in the network emerge via an infinite-period bifurcation, so that at birth, they exhibit a very large period of oscillation. This characteristic renders the oscillatory wave highly sensitive to symmetry-breaking effects, thus leading to a new detection mechanism. Model equations and bifurcation analysis are discussed in great detail. Results from experimental works on networks of fluxgate magnetometers are also included