The benefits of an asymmetric tri-stable energy harvester in low-frequency rotational motion

This letter investigates the benefits of an asymmetric tri-stable energy harvester in low-frequency rotational motion. A theoretical model framework is presented, which considers the effect of the rotational motion, to describe the dynamic characteristics and output voltage of the harvester. More importantly, the asymmetric tri-stable energy harvester is experimentally verified to be better than the symmetric one under various rotational speeds. The former exhibits a wide working rotational speed range of 140-460 rpm. The weight component of tip mass produces a periodic harmonic exciting force due to rotational motion, which can be designed to enhance energy harvesting.