Characterization of Laminated Magnetoelectric Vector Magnetometers to Assess Feasibility for Multi-Axis Gradiometer Configurations

Wide arrays of applications exist for sensing systems capable of magnetic field detection. A broad range of sensors are already used in this capacity, but future sensors need to increase sensitivity while remaining economical. A promising sensor system to meet these requirements is that of magnetoelectric (ME) laminates. ME sensors produce an electric field when a magnetic field is applied. While this ME effect exists to a limited degree in single phase materials, it is more easily achieved by laminating a magnetostrictive material, which deforms when exposed to a magnetic field, to a piezoelectric material. The transfer of strain from the magnetostrictive material to the piezoelectric material results in an electric field proportional to the induced magnetic field. Other fabrication techniques may impart the directionality needed to classify the ME sensor as a vector magnetometer. ME laminate sensors are more affordable to fabricate than competing vector magnetometers and with recent increases in sensitivity, have potential for use in arrays and gradiometer configurations. However, little is known about their total field detection, the effects of multiple sensors in close proximity and the signal processing needed for target localization. The goal for this project is to closely examine the single axis ME sensor response in different orientations with a moving magnetic dipole to assess the field detection capabilities. Multiple sensors were tested together to determine if the response characteristics are altered by the DC magnetic bias of ME sensors in close proximity. And finally, the ME sensor characteristics were compared to alternate vector magnetometers.