Piezoelectric-triboelectric-electromagnetic Hybrid Rotational Energy Harvesters (H-REH)

The rapid development of sensing technology has driven the global energy demand for micro-to-milliwatt continuous power supply and increased the need for energy harvesters. This study reports the hybrid rotational energy harvester (H-REH) comprising piezoelectric, triboelectric, and electromagnetic (EM) generators for energy harvesting from low-wind speeds. The H-REH prototype is fabricated and tested to evaluate the performance of simultaneously generating electrical power through the piezoelectric strips, triboelectric layers, and EM generators. Numerical models are developed to validate the experimental results, and satisfactory agreements are observed. The maximum electrical power is obtained as 121 µW, 191 µW, and 168 nW for the piezoelectric, EM, and triboelectric components at the wind speed of 3.5 m/s, respectively. In the end, we use the H-REH to power 130 LEDs while conducting the field test to display the energy harvesting performance visually. The reported H-REH can be applied for energy harvesting from low-high wind speeds.