The latest research findings from Professor Dong Shuxiang's research team in the Institute for Advanced Study, Shenzhen University and their collaborators were published online in Advanced Materials, on December 17, 2023. The paper titled " A High-Q Electric-Mechano-Magnetic Coupled Resonator for ELF/SLF Cross-Medium Magnetic Communication " proposed a new mechanism and method for Electric-Mechano-Magnetic (EMM) coupling in a centimeter-scale piezoelectric ceramic/ferromagnetic material heterogeneous structure, significantly enhancing EMM coupling. It inspires the design of Extremely Low Frequency/Super Low Frequency (ELF/SLF) mechanical antennas, and also offering new solutions for communication in challenging environments like underwater and underground. The first author of the paper is Dr. Chang Jianglei, with Professor Dong Shuxiang as the corresponding authors. The research team included Dr. Peng Wei, Dr. Ci Penghong, Ms Zheng Xinyi and Dr. Wang Bin from the same institute, as well as Professor Zhang Chunli and Dr. He Zhuangzhuang from Zhejiang University, and Dr. Xu Shupeng from East China Normal University.

ELF/SLF electromagnetic wave could effectively propagate in the harsh cross-medium environment where a high-frequency electromagnetic wave cannot pass due to the fast-decay. For efficiently transmitting a strong ELF/SLF radiation signal, the traditional electromagnetic antenna requires a super-large loop (>10 km). To address this issue, in this work,we report a piezoelectric ceramic/ferromagnetic heterogeneous structured, cantilever beam-typeelectric-mechano-magnetic (EMM) coupled resonatorat only centimeter scale for ELF/SLF cross-medium magnetic communication.Through designing hard-soft hybrid step-stiffness elastic beam, the resonator exhibits a much higher quality factor Q (~ 240) for ELF/SLF magnetic field transmitting, which is one to five orders of magnitude higher than those of previously reported mechanical antennas and loop coil antennas. Moreover, the resonator exhibits a 5000 times higher magnetic field emitting efficiency compared to a conventional loop coil antenna in ELF/SLF band.It also demonstrates a 200% increase in magnetic field emitting capacity compared to existing piezoelectric-driven antennas. Additionally, an ASK+PSK modulation method is proposed for suppressing relaxation time of the resonator,and a reduction in the relaxation time by 80% is observed. Furthermore, an air-seawater cross-medium magnetic field communication was successful demonstrated, indicating its potential as portable, high-efficient antenna for underwater and underground communications.

This work was supported by the National Key R&D Program of China. Link to the original article:https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202309159