Study On Nonlinear Vibration Piezoelectric Energy Harvester

The world moves toward greater find and utilize of new type energy sources in this energy-shortage-century. Among of the various energy harvesting technologies, the piezoelectric energy harvester has emerged as a prominent research area and continues to grow at a rapid pace. With the drive for alternative energy solutions, people need to find more efficient ways to power microchips. The key challenge will be amplifying the electrical energy generated by the piezoelectric materials and enable them to be integrated into low-cost and compact structures. Using nonlinear techniques, the piezoelectric energy harvester can obtain a wide vibration frequency and a higher output voltage. Based on the macro-structure of piezoelectric energy harvesting device model, the fabrication of the micro-energy harvester using MEMS technology has been paying more attention by many researchers.The nonlinear piezoelectric energy harvesters were design and investigated, which were based on the bimorph and the piezoelectric micro-cantilever respectively. The relevant background knowledge was introduced, including the piezoelectric theory, the nonlinear vibration theory and the piezoelectric harvesting theory. The fabrication processes of the nonlinear piezoelectric MEMS energy harvester were presented.As the nonlinear piezoelectric energy harvester which was based on the bimorph. the maximum output peak voltage improved from65V to104V under vibration acceleration of20m/s\the maximum output power was about0.48mW, and the resonant frequency various range was18Hz, it obtained that the resonant frequency of the nonlinear piezoelectric energy harvester can be changed in the small scope, and the output voltage was improved too. However, the bending moment is the main factor that led the output charge improved for the piezoelectric MEMS energy harvester, which maximum output charge was18pC under input excitation voltage of7.2V, the maximum output charge was increased by four times compared to the similar case of the linear piezoelectric MEMS energy harvester, its output maximum power was0.0106nW.