2D magnetic field sensing array using face-shear mode PMN-PT/Metglas composite
© 2020 IOP Publishing Ltd. A magnetic field sensor based on the ΔE effect (the change of elastic modulus of the MS phase under external magnetic field) was designed and fabricated using 36-face shear mode piezoelectric (PE)/magnetostriction (MS) composite. This device was proposed to sense a magnetic field by monitoring the change of the device electrical impedance in magnetic fields. The electrical impedance changes due to ΔE effect and the electromechanical coupling factor of the composite were experimentally and theoretical explored. The dynamic range for the 36-face shear mode composite is found to be ∼400% larger than a 31/32 extensional mode composite. Of particular importance is that the proposed magnetoelectric (ME) sensor based the ΔE effect is able to sense a weak magnetic field without bulky AC/DC excitation coils, which are usually used in the traditional ME sensor based on magneto-mechano-electric coupling effect. A two-dimensional (2D) magnet target imaging array was designed based on the PE/MS magnetic field sensor to image a target magnet located at different distances and with different orientations at room temperature. This design provides a good paradigm for 2D magnetic field sensing and imaging with a simple PE/MS composite sensor structure.