Multifrequency Response Magnetoelectric Cantilever Beam Devices for Magnetic Field Energy Harvesting and Detection

In this work, magnetoelectric (ME) Galfenol/PZT cantilever beam devices with varying lengths were designed and fabricated. The devices exhibited a multifrequency response of the ME coupling effect, with the maximum value of ME coupling coefficient ( $\alpha _{\text {ME}}{)}$ of the 35-mm ME cantilever beam device reaching 80.2 V/(cm $\cdot $ Oe) at resonance frequency. The variation of $\alpha _{\text {ME}}$ with magnetic field exhibits an in-plane anisotropy. Additionally, the relationship between ME output voltage and ac excitation field displays great linearity and sensitivity, indicating the potential for the ME cantilever beam device to measure magnetic field space angle. Notably, the peak voltage of the ME output voltage is high, and the maximum output power of the 35-mm-long ME cantilever beam device is 0.11 mW under a 2.80-Oe ac magnetic field, which is sufficient to drive 31 light-emitting diodes (LEDs) for illumination. Thus, the ME cantilever beam device provides an experimental basis and device prototype for wireless sensor networks, serving as a promising microenergy source by harvesting stray weak magnetic field energy.