One of the new materials that have recently attracted wide attention of researchers are magnetoelectric (ME) composites. Great interest in these materials is due to their properties associated with the transformation of electric polarization/magnetization under the influence of external magnetic/electric fields and the possibility of their use to create new devices. In the proposed review, ME magnetic field sensors based on the widely used structures Terfenol—PZT/PMN-PT, Metglas—PZT/PMN-PT, and Metglas—Lithium niobate, among others, are considered as the first applications of the ME effect in technology. Estimates of the parameters of ME sensors are given, and comparative characteristics of magnetic field sensors are presented. Taking into account the high sensitivity of ME magnetic field sensors, comparable to superconducting quantum interference devices (SQUIDs), we discuss the areas of their application.
In this work a magnetoelectric (ME) current sensor design based on a magnetoelectric effect is presented and discussed. The resonant and non-resonant type of ME current sensors are considered. Theoretical calculations of the ME current sensors by the equivalent circuit method were conducted. The application of different sensors using the new effects, for example, the ME effect, is made possible with the development of new ME composites. A large number of studies conducted in the field of new composites, allowed us to obtain a high magnetostrictive-piezoelectric laminate sensitivity. An optimal ME structure composition was matched. The characterization of a non-resonant current sensor showed that in the operation range to 5 A, the sensor had a sensitivity of 0.34 V/A, non-linearity less than 1% and for a resonant current sensor in the same operation range, the sensitivity was of 0.53 V/A, non-linearity less than 0.5%.
Ever-evolving advances in flexible magnetic sensors are promising to fuel technological developments in the fields of touchless human–machine interaction, implantable medical diagnosis, and magnetoreception for artificial intelligence. However, the realization of highly flexible and extremely sensitive magnetic sensors remains a challenge. Here, we report a cost-effective, flexible, and ultra-sensitive heterostructural magnetoelectric (ME) sensor consisting of piezoelectric Pb(Zr0.52Ti0.48)O3 (PZT) thick films and Metglas foils. The flexible sensor exhibits a strong ME coefficient of 19.3 V cm−1 Oe−1 at low frequencies and 280.5 V cm−1 Oe−1 at resonance due to the exceptionally high piezoelectric coefficient d33 ∼ 72 pC N−1 of the constituent PZT thick films. The flexible ME sensor possesses not only ultrahigh sensitivities of 200 nT at low frequencies and 200 pT at resonance but also shows an excellent mechanical endurance. Through 5000 bending cycles (radii of ∼1 cm), the sensors showed no fatigue-induced performance degradation. This ultrasensitive flexible sensor provides a platform capable of sensing and responding to external magnetic fields and will find applications in soft robotics, wearable healthcare monitoring, and consumer electronics.
A rapid surge in the research on very low frequency (VLF) antennas is occurring due to the demand for radio navigation and special environment communications such as underwater and underground applications. Among them, magnetoelectric (ME) antennas have recently proven to be a prospective solution for miniaturization of VLF communication systems. However, the essential magnetic bias fields (Hdc) lead to challenges of miniaturization, electromagnetic interference, and noise sources for ME antenna application. Here, a bias-free VLF ME antenna based on the magneto-gradient ME composite (i.e., annealed Metglas/Metglas/PZT/Metglas/annealed Metglas) has been designed. Owing to the interaction effect between multi-unannealed/annealed Metglas, the magneto-gradient ME composite exhibits a large direct and converse ME response (αDME = 107 V/cm Oe and αCME = 9 Gs/V at resonance) at bias-free, which is about 63% and 33% of the maximum value under optimal magnetic bias for unannealed ME composites. Moreover, a digital amplitude shift keying (ASK) modulation method is proved suitable for the as-made bias-free VLF ME antenna. Such a bias-free ME antenna provides a practicable strategy for miniaturization of VLF communication.
Wireless communication has always been an indispensable element in the modern information‐based society. Beyond the commercial electrical antenna, very low frequency (VLF) mechanical antennas have recently become research hotspot since their combination of miniaturization and favorable radiation efficiency in lossy electrically conductive environments. However, their usage is challenged due to the relatively limited radiation capability and modulation bandwidth. This study demonstrates an improved high‐efficiency magnetoelectric (ME) mechanical antenna based on the magneto‐mechano‐electric (MME) effect, realized via the synergistic effect of piezo‐driven magnets motion and converse magnetoelectricity (ME). Converse ME coefficient and radiation measurement show that the MME antenna demonstrates superior performance over a normal ME antenna. The oscillation magnet serves as an extra vibrating magnetic dipole besides the ME composite and thus brings radiation enhancement to the mechanical antenna. Furthermore, digital signal modulations are conducted with a VLF carrier signal to enable anti‐interference and anti‐attenuation communication. In view of the exemplary demonstration, the MME effect‐based antenna is expected to provide a new strategy for mechanical antenna improvement and shows tremendous potential for conductive environments communication applications.
Long-wave antennas are extensively used in special environment communications, such as underwater and underground applications, but the huge size of traditional electrical antennas restricts their applications. The emergent acoustically excited magnetoelectric (ME) antennas is expected to solve the portability problem. However, the contradiction between the radiation intensity and modulation rate (i.e., baud rate) of ME antenna remains an obstacle to its development. Here, we propose a very low frequency (VLF, 3–30 kHz) ME antenna based on a Rosen-type magnetostrictive-piezoelectric ME composite, which collaboratively optimizes both radiation intensity and transmission rate. The radiation intensity and efficiency of the proposed ME antenna were, respectively, two and three orders of magnitude higher than those of a same-sized loop antenna. A VLF communication system based on the Rosen-type ME antenna utilized amplitude shift keying (ASK) modulation was demonstrated. The system achieved an ultra-high baud rate of up to 2 kbaud (i.e., 2 kbps bit rate), confirming the feasibility of this approach.