A Magnetically Coupled Piezoelectric Rotational Energy Harvester with Dual Operational Mode for Both Low and High Angular Velocities

Existing literature on rotational energy harvesters is limited to designs optimized for either low or high rotational speeds, lacking versatility in operational frequency bandwidth. This paper proposes a magnetically coupled piezoelectric rotational energy harvester capable of operating in two distinct modes to capture energy from both low and high angular velocities. At low rotational speeds, the harvester operates in a gravitational mode; while at high speeds, a centripetal force induced bi-stability mode is engaged as a nonlinear oscillatory mechanism. Numerical simulations evidence the feasibility of activating both of these modes. The initial feasibility result presented here gives confidence to further develop the proposed system as a potential versatile rotational energy harvester capable of capturing kinetic energy from a broadband spectrum of angular velocities.