3D impact-based ALN/SUS microenergy harvesters for multi-directional and low-frequency vibrations

In this study, we developed the novel three-dimensional (3D) impact-based microenergy harvesters for harvesting random vibrations from multiple directions. The device consisted of a 3D box built up from the flexible AlN/SUS-based microcantilevers and the free-moving SUS ball. When the ball receives external vibration energy, it might strike the cantilevers on the surrounding walls and then the device generates electricity. The merit of this configuration is the device could generate the electricity from low frequency and multi-directional vibrations. The developed device provided the peak output power 70 nW on average for the triaxial vibrations at the extremely low frequency of 4.5 Hz which frequency regime is very difficult to be harvested by the published microenergy harvesters.