2D magnetic field sensing array using face-shear mode PMN-PT/Metglas composite

Abstract

A magnetic field sensor based on the ∆E 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 ∆E 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 ∆E 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.