A Flapping Airflow Energy Harvester with Flexible Wing Sections

This paper reports a novel method to improve output power of a flapping airflow energy harvester by introducing flexible wing sections. The flapping airflow energy harvester consists of a cantilever beam structure with a wing at its free end. A bluff body is placed in front of the wing to induce aerodynamic instability that leads to up and down oscillation of the wing. By coupling transducers to the oscillating wing, electromagnetic in this case, electrical energy can be generated. In this research, instead of using a commonly used rigid wing, the proposed airflow energy harvester has flexible wing sections that are able to bend, thus reduce the aerodynamic resistance during the wing oscillation. Therefore, the overall mechanical damping can be reduced and output power of the proposed energy harvester is increased. It is found experimentally that the proposed method is able to improve energy harvester performance of flapping airflow energy harvesters under high airflow speeds.