A dual auxiliary beam galloping triboelectric nanogenerator for low speed wind energy harvesting

Aiming to improve the energy harvesting efficiency under low wind speed, we propose a dual auxiliary beam galloping triboelectric nanogenerator (GTENG) in this work. The structural design of a single main beam and a pair of auxiliary beams enables the device to work under a higher vibration frequency when triggered by wind. A stable and improved working frequency of about 4.6 Hz was observed at various wind speeds. The device started to vibrate at a wind speed of 1.7 m/s and generated an output voltage of about 100 V. The outputs of this GTENG approach to saturation at a wind speed of around 5 m/s. The output voltage and short-circuit current reached 260 V and 20 μA, respectively. A maximum power of about 1 mW was obtained under a wind speed of 5.7 m/s with a load of 33 MΩ. Moreover, the effectivity and long-term stability of the device were demonstrated under low wind speeds. A digital watch is powered for 45 s after charging a 47 μF capacitor for 120 s at a wind speed of 3.1 m/s.