Enhanced extremely weak-field energy harvesting via magnetic flux and stress concentration effects in ferromagnetic/ferroelectric composite

Abstract

In this work, we report an enhanced magneto-mechano-electric (MME) coupling in Ni/Pb(Zr,Ti)O3 (PZT) ceramic composited ladder-type cantilever attached with a tip mass of NdFeB magnet, which simultaneously exhibits the magnetic flux concentration effect and the stress concentration effect, and therefore, it shows an enhanced extremely weak-field (EWF) coupling ability. Investigations show that the proposed MME energy harvester (EH) can generate an output power density of 7.16  μW Hz−1 Oe−2 cm−3, which is the highest value compared to the state of the art MME energy harvesters. Under an EWF of even as low as Hac = 0.1 Oe (about half level of the geomagnetic field), the proposed MME-EH can still produce a peak–peak output power of 23.5  μW, which is enough power to light up 4 LEDs in real time. Furthermore, it can drive a wireless sensor communication system in real time under a weak Hac = 0.75 Oe excitation, demonstrating it has potential to serve as a micro-energy source of wireless sensor networks in EWF circumstance. This work is not only beneficial but has also inspired future multi-function-integrated material and smart electronic device designs in Internet of Things in EWF circumstance.