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Promote efficiency of harvesting vibration energy by tailoring potential energy with addition of magnets

Large-amplitude snap-through motion might happen between two equilibria of a buckling inverted piezoelectric beam under vibration excitation, therefore enhancing the energy harvesting performance of system significantly. However, in practical application, owing to the deep potential well of a buckling beam, relatively large excitation amplitude is needed to trigger such snap-through motion. To overcome this limitation, we herein propose an improved inverted beam harvester that comprises an inverted beam with an affixed tip magnet and two additional magnets mounted in the vicinity of the equilibrium positions. By introducing this repulsive magnetic force, the potential energy could be tailored to promote the occurrence of snap-through motion. Numerical simulation is conducted and it is shown that with the proposed design the harvester would be able to realize snap-through motion more easily compared to the original buckling system. This has also been validated by the experiment in which large deflection and voltage output are both observed when snap-through motion is activated under low excitation frequency.