Experimental Investigation of Three-Dimensional Multi-Directional Piezoelectric Wind Energy Harvester.

The wind-induced vibration energy harvester is a type of ideal power source for wireless sensor nodes. To adapt to the uncertainty of wind direction in natural environments, this paper proposes a three-dimensional multi-directional piezoelectric wind energy harvester (WEH), whose bluff body is an external shell with the shape like a lampshade, supported by three internal piezoelectric composite beams. A harvester prototype was made using 3D printing technology, and its multi-directional energy harvesting characteristics were systematically tested in a wind tunnel. Experiments show that it can harvest wind energy from any direction in three-dimensional space. When the wind speed is about 15 m/s and the wind direction changes in the horizontal plane, the minimum to maximum total average output power ratio is about 0.84. This work provides an experimental basis for the future development of three-dimensional multi-directional WEHs to some extent.