Theoretical and experimental investigation of a bi-stable piezoelectric energy harvester incorporating fluid-induced vibration

Vibration-based piezoelectric energy harvesting has potential applications in the effective energy supply for sensors and communication devices. To address the need to increase the levels of harvested energy and adjust the low-frequency bandwidth, we design a bi-stable piezoelectric energy harvester (BS-PEH) incorporating fluid-induced vibration, which only needs to simply modify equipment that exists fluid tank. A theoretical model based on fluid equivalence is established to construct the dynamic equation and electromechanical coupling equations of the proposed BS-PEH. Experimental results investigate the validity of the theoretical model, and the comparison with the existing literature also shows the superiority in power density. Then the sensitivity of the averaged power to uncertain resistive load is given and analyzed, and the improvement of energy harvesting capacity by bi-stable structure is discussed. Subsequently, the parametric study for design parameters reveals the influence of each parameter on the output characteristics of BS-PEH and gives the configuration of optimizing energy harvesting. Moreover, the proposed BS-PEH is easy to design, and a higher energy harvesting efficiency can be achieved by simply changing the accessories, in which modifying the slider mass can make the output power reach 81mW.