Flutter-driven triboelectrification for harvesting wind energy

Technologies to harvest electrical energy from wind have vast potentials because wind is one of the cleanest and most sustainable energy sources that nature provides. Here we propose a flutter-driven triboelectric generator that uses contact electrification caused by the self-sustained oscillation of flags. We study the coupled interaction between a fluttering flexible flag and a rigid plate. In doing so, we find three distinct contact modes: single, double and chaotic. The flutter-driven triboelectric generator having small dimensions of 7.5 x 5cm at wind speed of 15 ms(-1) exhibits high-electrical performances: an instantaneous output voltage of 200V and a current of 60 mu A with a high frequency of 158 Hz, giving an average power density of approximately 0.86mW. The flutter-driven triboelectric generation is a promising technology to drive electric devices in the outdoor environments in a sustainable manner.