Modeling, fabrication, and experimental validation of hybrid piezo-magnetostrictive and piezomagnetic energy harvesting units

As sources of energy are becoming more scarce and expensive, energy harvesting technologies that convert ambient energy to electrical energy are receiving more global interest. Proposed in this article are two hybrid energy harvesters that each employs a combination of piezoelectric (PZT), magnetostrictive (MSM), and electromagnetic technologies. Harvesters employ spiral geometries to allow smaller natural frequencies compared to a straight beam. In particular, the hybrid technology that uses piezoelectric and magnetostrictive has shown significant improvement in the frequency bandwidth of the device. The two harvesters are fabricated, modeled, and tested for their voltage, power, and displacement outputs. The test results are shown to be in good agreement with those obtained from the model.