Power and Bandwidth Enhancement through Asymmetric Bi-stable Design for Piezoelectric Energy Harvesters

Efficiently collecting ambient vibrations has been the research hotspot of energy harvesting technology. In this paper, an asymmetric bi-stable energy harvester is proposed to tune the bandwidth as well as to enhance the output power. By only shifting the magnet positions from symmetric to asymmetric, and requiring no ancillary mechanical structures, asymmetric double potential wells can be constructed, working bandwidth can be extended, and average output power can be increased by 10.2%. Maximally, the asymmetric bi-stable energy harvester prototype generates root mean square voltage of 3.173V on 90.5MΩ resistance @9.5Hz excitation.