A magnetoelastic tag includes a frame-suspended magnetoelastic resonator that combines a strong resonant response with a relatively small resonator, enabling magnetoelastic sensor use in a variety of inconspicuous applications and/or small packages. The resonator is suspended with respect to a substrate, which reduces, minimizes, or eliminates interaction between the substrate and resonator. Signal strength is thereby enhanced, thereby allowing miniaturization while maintaining a measurable response to the interrogation field. The resonator can have a hexagonal shape and/or be suspended at particular locations about its perimeter to promote signal generation in a direction different from that of the interrogation field. A sensor can include one or more frame-suspended resonators, which can be arranged in an array, stacked, or randomly where a plurality of resonators is employed.

A system for an acoustically driven ferromagnetic resonance (ADFMR) based sensor. The system may include a power source, that provides an electrical signal to power the system, at least one circuit comprising a set of ADFMR circuits, sensitive to external electromagnetic fields, a power splitter, a power combiner and a detector circuit. The system functions to detect and measure external electromagnetic (EM) fields by measuring a perturbation of the electrical signal through the ADFMR circuits due to the EM fields.

A system for an acoustically driven ferromagnetic resonance (ADFMR) based sensor. The system may include a power source, that provides an electrical signal to power the system, at least one circuit comprising a set of ADFMR circuits, sensitive to external electromagnetic fields, a power splitter, a power combiner and a detector circuit. The system functions to detect and measure external electromagnetic (EM) fields by measuring a perturbation of the electrical signal through the ADFMR circuits due to the EM fields.

A magnetostrictive displacement sensor includes a sensor assembly having a printed circuit board (PCB), an anchor attached to the PCB, a waveguide having a first end attached to the anchor, and a sensing element. The sensing element includes a rigid member and a coil. The rigid member is attached to the waveguide and extends through an opening in the PCB and is configured to experience a strain in response to a magnetostrictive response in in the waveguide. The coil is attached to the PCB and surrounds the rigid member and the opening. The coil is configured to output a sensor signal that includes an indicator, which is produced in response to the strain in the rigid member.

An acoustically driven ferromagnetic resonance (ADFMR) device has a piezoelectric element comprised of piezoelectric material, first and second electrodes arranged in a vertical stack with the piezoelectric element to activate the piezoelectric element to generate an acoustic wave, a radio frequency voltage source electrically connected to the first electrode, a magnet comprised of a magnetostrictive material to receive the acoustic wave, the magnet being in the vertical stack with the first and second electrodes and the piezoelectric element, wherein the acoustic wave resonates at a ferromagnetic resonance of the magnetostrictive material, and a readout circuit to detect a change in the acoustic wave by detecting g one of an output voltage amplitude, a change in impedance or a reflection of the acoustic wave in the magnet to measure an unknown magnetic field in which the ADFMR device resides and as experienced at the magnetostrictive element.

An acoustically driven ferromagnetic resonance (ADFMR) device has a piezoelectric element comprised of piezoelectric material, first and second electrodes arranged in a vertical stack with the piezoelectric element to activate the piezoelectric element to generate an acoustic wave, a radio frequency voltage source electrically connected to the first electrode, a magnet comprised of a magnetostrictive material to receive the acoustic wave, the magnet being in the vertical stack with the first and second electrodes and the piezoelectric element, wherein the acoustic wave resonates at a ferromagnetic resonance of the magnetostrictive material, and a readout circuit to detect a change in the acoustic wave by detecting g one of an output voltage amplitude, a change in impedance or a reflection of the acoustic wave in the magnet to measure an unknown magnetic field in which the ADFMR device resides and as experienced at the magnetostrictive element.

A magnetostrictive film includes rich regions having a mesh pattern in a cross section perpendicular to a film thickness direction of the magnetostrictive film. The rich regions are richer in a specific element contributing to ferromagnetism than surroundings of the rich regions.

A magnetostrictive film includes rich regions having a mesh pattern in a cross section perpendicular to a film thickness direction of the magnetostrictive film. The rich regions are richer in a specific element contributing to ferromagnetism than surroundings of the rich regions.

Acoustically driven ferromagnetic resonance (ADFMR) sensor apparatuses may be tuned by the application of a tuning voltage. A tunable ADFMR sensor apparatus may include one or more tuning electrical contacts that are configured to adjust the output of the ADFMR magnetic field sensor, e.g., by applying a voltage to adjust a magnetic property of the multiferroic magnetic material of the ADFMR magnetic field sensor. Tuning may be performed in real time, or near-real time, based on an output of the ADFMR magnetic field sensor. In some cases tuning may include field zeroing and/or adjusting the range of field measurements.

Acoustically driven ferromagnetic resonance (ADFMR) sensor apparatuses may be tuned by the application of a tuning voltage. A tunable ADFMR sensor apparatus may include one or more tuning electrical contacts that are configured to adjust the output of the ADFMR magnetic field sensor, e.g., by applying a voltage to adjust a magnetic property of the multiferroic magnetic material of the ADFMR magnetic field sensor. Tuning may be performed in real time, or near-real time, based on an output of the ADFMR magnetic field sensor. In some cases tuning may include field zeroing and/or adjusting the range of field measurements.