The internet of things (IoT) has revolutionized society by creating a network of interconnected devices with sensors, processing ability and software for data exchange. However, the expansion of IoT places undue strain on energy resources. Thus, the development of low-power components is critical. Moreover, the demand for IoT has opened new markets for wearable technologies, necessitating innovations towards miniaturization. This rapid growth introduces further challenges in communication and environmental adaptability. Magnetoelectric (ME) microelectromechanical and nanoelectromechanical systems (M/NEMS) introduce unparalleled properties to reshape the IoT landscape. ME M/NEMS enable a 100,000× reduction in wavelength, resulting in reduced size and weight, and provide multifunctionality, such as simultaneous sensing, data transmission and wireless power transfer. With renewed interest in ME M/NEMS platforms, several disruptive technologies have emerged ranging from ultra-compact radiofrequency front-ends to quantum sensing, computing and communication networks. This Review delves into ME materials, ME composites and ME M/NEMS for IoT functions, including logic memory; magnetic sensing; wireless power transfer; ultra-compact antennas; power, radiofrequency and microwave electronics; and communication systems.

Magnetoelectric (ME) devices combining piezoelectric and magnetostrictive materials have emerged as powerful tools to miniaturize and enhance sensing and communication technologies. This paper examines recent developments in bulk acoustic wave (BAW) and surface acoustic wave (SAW) ME devices, which demonstrate unique capabilities in ultra-sensitive magnetic sensing, compact antennas, and quantum applications. Leveraging the mechanical resonance of BAW and SAW modes, ME sensors achieve the femto- to pico-Tesla sensitivity ideal for biomedical applications, while ME antennas, operating at acoustic resonance, allow significant size reduction, with high radiation gain and efficiency, which is suited for bandwidth-restricted applications. In addition, ME non-reciprocal magnetoacoustic devices using hybrid magnetoacoustic waves present novel solutions for RF isolation, which have also shown potential for the efficient control of quantum defects, such as negatively charged nitrogen-vacancy (NV⁻) centers. Continued advancements in materials and device structures are expected to further enhance ME device performance, positioning them as key components in future bio-sensing, wireless communication, and quantum information technologies.

As the rapid development of integrated magnetic and magnetoelectric, numerous novel devices including high performance on-chip transformers, inductors, filters, antennas, and sensors with unique advantages in power efficiency, size and tunability, etc. have been demonstrated. In this review, an overview of the development of magnetism and magnetoelectric will be firstly given. The conceptual illustration and materials used in integrated magnetoelectric will then be presented. Selections of on-chip devices from literatures will be shown to exemplify the integrated magnetic and magnetoelectric applications. Finally, the prospect and the direction of the future research will be discussed in the conclusion.

The miniaturization of antennas has been a significant challenge in the field of electronics and telecommunications. In recent years, mechanically driven thin‐film bulk acoustic resonator (FBAR) magnetoelectric (ME) antennas have emerged as a promising solution, demonstrating superior miniaturization capabilities compared to conventional state‐of‐the‐art compact antennas. While nanoelectromechanical systems (NEMS) FBAR ME antennas exhibit high miniaturization potential, their suspended thin‐film heterostructures render them fragile and exhibit low power handling capabilities. The findings demonstrate that solidly mounted resonator (SMR) NEMS ME antennas on a Bragg acoustic resonant reflector offer a compelling solution. With a circular resonating disk of 200 μm diameter operating at 1.75 GHz, these SMR‐based antennas display a high antenna gain of −18.8 dBi and a 1 dB compression point (P1dB) of 30.4 dBm. Compared to same‐size FBAR ME antennas with a free‐standing membrane, SMR‐based antennas exhibit significantly higher structural stability and 23.3 dB stronger power handling capability, in addition to easier fabrication processes. The compatibility of the simple fabrication processes with complementary metal–oxide–semiconductor technology, along with the dramatic miniaturization, high power handling, robust mechanical properties, and much higher antenna radiation gain, make these SMR‐based ME antennas a promising candidate for future antenna systems.

Compact, conformal antennas with ground plane immunity and high gain are crucial to IoT, 5G, and biomedical applications. Conventional electrical antennas suffer large size, detuned impedance, and degraded gain and radiation efficiency on a ground plane as they operate on electromagnetic resonance and use electric dipole for radiation. Utilizing electromechanical resonance, magnetoelectric(ME) coupling, and magnetic dipole radiation in magnetostrictive/piezoelectric heterostructures, ME antennas exhibit ultra‐compact sizes comparable to acoustic wavelength and enhanced radiation performance on a ground plane. This study first utilizes parallel and series antenna array topology to achieve a profound gain and radiation efficiency enhancement without degrading impedance mismatch and quality factor of ME resonators. Notably, by increasing the array element number, 10 dBi gain enhancement is achieved in 3 × 3 thin‐film bulk acoustic resonator (FBAR) ME antenna array, reaching a peak antenna gain of −17.3 dBi. Unlike conventional antenna arrays, ME antenna arrays enhance radiation efficiency without affecting directivity, owing to ultra‐compact dimensions much less than one‐quarter of electromagnetic wavelength. Their ground plane immunity and 3 dB gain enhancement on ground planes with different shapes are also demonstrated. The demonstrated ME antenna arrays are outstanding platform‐independent ultra‐compact high‐gain conformal antenna candidates for wireless communication, wireless power transfer, and portable electronic and biomedical devices.

We provide the clearest experimental evidence to date that positive leader velocity decreases with the decline of air density in the troposphere. The experiments are conducted at altitudes of 4,300 m in Tibet and 53 m in Beijing using the long air gap discharge technique. Rigorous comparative studies are performed using synchronized measurement of positive leader velocity and current under different air densities and similar temperature and humidity conditions. The effect of reduced air density on positive leader velocity is analyzed with a detailed thermal‐hydrodynamic model. It is found that the widely used similarity law setting initial leader radius inversely proportional to air density does not hold in estimating positive leader speeds in the troposphere.