Improve efficiency of harvesting random energy by snap-through in a quad-stable harvester

• Published in: Sensors and actuators. A. Physical. 2016-06, Vol.243, p.151-158
• Main Authors: Zhou, Zhiyong, Qin, Weiyang, Zhu, Pei
• Format: Article
• Language: English
• Subjects: Cantilever beams; Devices; Electric potential; Energy harvesting; Energy management; Harvesters; Harvesting; Magnet; Piezoelectric beam; Quad-stable energy harvester; Random excitation; Snap-through
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2016.03.024

•The quad-stable energy harvester has a wider range of frequencies under low level excitations.•The quad-stable configuration can easily attain snap-through oscillations under random excitations.•The quad-stable energy harvester can produce higher output voltage and improve the harvesting efficiency dramatically compared with the traditional bi-stable energy harvester. In response to the defects of the bi-stable energy harvester (BEH), we develop a novel quad-stable energy harvester (QEH) to improve the harvesting efficiency. The device is made up of a bimorph cantilever beam having a tip magnet and three external fixed magnets. By introducing the repulsion forces between magnets, the function of potential energy of the QEH is given. It owns four potential wells. It is proved that the quad-stable harvester can cross the barriers and realize snap-through easier. Validation experiments were performed by frequency sweeping and random excitations. Results show that compared to the BEH the frequency bandwidth of snap-through of the novel device is much wider. The QEH can make a dense snap-through in response under random excitation, and give out a large output voltage. This shows that the proposed QEH is more effective in energy harvesting applications.