Finding an efficient way for underwater communication with a portable antenna at very-low frequency (VLF 3-30 kHz) is challenging since the conventional electrical antennas require the size to be larger than 1/10 of the wavelength. Recently, acoustically driven antennas were proposed to realize portable VLF communication in air but lack the demonstration in a lossy environment. Here, we reported the first VLF underwater communication system based on a pair of acoustically actuated magnetoelectric (ME) antennas with small size of 10 cm in length. A theoretical analysis of reflection and radiation performance of the ME antenna was conducted, where the electromechanical resonance (EMR) frequency and effective magnetic dipole moment were estimated, and a near-field coupling model of a pair of ME antennas was further established. The results of theoretical predictions and finite element (FEM) simulations were then compared with experimental measurements and their differences were discussed. A prototype of underwater communication system based on the ME antenna pair was finally presented, where a binary digital modulation with a bit rate of 100 bps has been demonstrated, confirming the feasibility of ME antennas for portable underwater communication.

A giant magnetoelectric (ME) effect in self-biased annealed Metglas/Pb(Zr,Ti)O₃/Metglas laminates under zero magnetic bias is reported. The remanent magnetization was increased by annealing Metglas, which generated an internal bias field. This shifted the M-H hysteresis loops, yielding large values for the ME voltage coefficient of α_ME = 12 V/cm·Oe and 380 V/cm·Oe at 1 kHz and electromechanical resonance under zero magnetic bias, respectively. This self-biased laminate is shown to have a high sensitivity to ac magnetic fields.

We report the direct measurement of a magnetoelectric (ME) exchange between magnetostrictive ${\text{CoFe}}_2{\text{O}}_4$ nanopillars in a piezoelectric ${\text{BiFeO}}_3$ matrix for single-layer nanocomposite epitaxial thin films grown on (001) ${\text{SrTiO}}_3$ substrates with ${\text{SrRuO}}_3$ bottom electrodes. The ME coefficient was measured by a magnetic cantilever method and had a maximum value of $\sim 20\text{mV}/\text{cm}\text{Oe}$ . The films possessed saturation polarization $\left(60\mu \text{C}/{\text{cm}}^2\right)$ and magnetization (410 emu/cc) properties equivalent to bulk values, with typical hysteresis loops.