Since the revival of multiferroic laminates with giant magnetoelectric (ME) coefficients, a variety of multifunctional ME devices, such as sensor, inductor, filter, antenna etc. have been developed. Magnetoelastic materials, which couple the magnetization and strain together, have recently attracted ever-increasing attention due to their key roles in ME applications. This review starts with a brief introduction to the early research efforts in the field of multiferroic materials and moves to the recent work on magnetoelectric coupling and their applications based on both bulk and thin-film materials. This is followed by sections summarizing historical works and solving the challenges specific to the fabrication and characterization of magnetoelastic materials with large magnetostriction constants. After presenting the magnetostrictive thin films and their static and dynamic properties, we review micro-electromechanical systems (MEMS) and bulk devices utilizing ME effect. Finally, some open questions and future application directions where the community could head for magnetoelastic materials will be discussed.
It is an important engineering challenge to detect a weak magnetic field ${H}_{AC}$ at low frequencies (1-100 Hz) due to large noise. In this work, a magnetoelectric (ME) sensor using single-crystal quartz material as the piezoelectric phase and optimized magnetostrictive layers has been presented to sense the low-frequency magnetic field signals. Firstly, the ME response properties of the bulk Metglas/quartz/Metglas laminate sensor were studied and a high ME coefficient of 3038 V/(cm $\cdot $ Oe) has been attained in its electromechanical resonance frequency. With frequency modulation technique, which a magnetic low-frequency signal can be transferred to around resonance frequency of the sensor, the proposed sensor was used to detect the low frequency magnetic field signals under zero bias conditions. It is experimentally found that the absolute resolution with respect to a 1 Hz magnetic field can be decreased as low as 44 pT ± 1.41 pT with 20 layers of Metglas. More importantly, the ME coefficients with different layers under zero bias and the effect of Metglas layers on the limit of the detection at 1 Hz also have been investigated. The results show that the limit of the detection at 1 Hz can be decreased to 10 pT ± 0.32 pT with 14 layers of Metglas which indicates an enhancement by 4.4 times in comparison with 20 layers. This simple bulk Metglas/quartz/Metglas laminate sensor with optimized layers has a great potential to be used for low-frequency bio-magnetic signals measurement at room temperature.
Mutual inductance highly determines the performance of dual-coil magnetic coupled resonance wireless power transfer (MCR-WPT). Due to the frequency splitting, the system gives inferior energy transfer efficiency in overcoupled state, where the two coils are close with each other and a large mutual inductance is presented. This raises the need to finely tune the mutual inductance for frequency splitting elimination and consequently performance optimization. Meanwhile, with the built MCR-WPT system, the mutual inductance remains constant given a fixed distance between the coils, which limits its potential application. In this article, the resonant coils with magnetoelectric composites core consisting of Metglas/lead zirconate titanate/Metglas were adopted to tune the mutual inductance. A large tunability of 56.5% in the low-frequency range and a tunability of 16.6% in the high-frequency range were achieved. The tunability of the mutual inductance indicates its great potential and provides a new route to eliminate the frequency splitting for high efficient MCR-WPT.
This study proposes a three-dimensional (3D) dumbbell-shaped magnetoelectric antenna that utilizes an acoustic resonance mechanism to circumvent fundamental dimensional constraints inherent in conventional electromagnetic radiators and to address the critical demand for operating frequency reduction in compact very low frequency (VLF) antennas for lossy-media communications. The proposed architecture features a custom constricted central cross section geometry that is engineered to downshift the operational frequency band through the manipulation of topological mass and equivalent stiffness distribution. Tapering the central segment intrinsically reduces the equivalent structural stiffness, breaking the low-frequency limitations of standard cylindrical geometries while simultaneously enhancing stress-mediated electromechanical coupling. A composite bar vibration theory-based Mason equivalent network model clarifies this structural reconfiguration and confirms highly efficient energy conversion and radiation performance. Prototype experimental evaluations demonstrate a reduction in the fundamental longitudinal resonance frequency to 13.8 kHz through the dumbbell-shaped geometry. This reduction constitutes an effective frequency downshift compared to standard cylindrical benchmarks without expanding the overall physical volume. The geometric design simultaneously induces a stress enhancement effect that stabilizes electromechanical responses and increases the radiation resistance required for long-distance VLF transmission. This designed geometric structure presents a feasible strategy for addressing space-constrained antenna limitations and serves as a potential design reference for integrating high-performance VLF wireless systems into mobile and underwater platforms.