Study On Vibrational Power Harvesting From Environment Based On Piezoelectric Cantilever Structures

The energy of vibration in the natural environment is widely spread, and the miniature vibration-based generator may withdraw it and transform into the energy which may use directly. Among them, vibration-based generator acquirement most attention as piezoelectric mode for its advantage of working condition without power source, high mechanical and electrical coupling characteristic and power density. This kind of generator largely extent, uses the piezoelectric cantilever structure as inverting element. For the reason that of simple structure and convenient processing, the resonance frequency, geometry and material of piezoelectric cantilevers have an immediate effect on working condition and output of energy harvesting device.In order to implement a device of high power output and work under the natural environment, this article has established the piezoelectric cantilever model for vibrational energy harvesting. Theoretical analysis and ANSYS finite element analysis were carried on, in view of its key component——piezoelectric beam, including its energy conversion process, resonance frequency solution and output. Resonance frequencies of piezoelectric cantilever structures were measured via Doppler vibration meter, and the experimental platform was built as well. Result of experiment finally could be used for realizing the vibrational energy gathering, thus the dream of solution by micro power supply for micro power loss component and wireless sensor node may come true.Main Content:1. Introduction of vibration-based generator, especially the principle and present research for those use piezoelectric cantilever structures, as well as existent problem.2. Based on the characteristic of environment vibration, model of energy harvesting device using piezoelectric cantilever was established.3. Theoretical analyses of piezoelectric cantilever were carried on for material characteristic, electric equivalent circuit and so on. The formulas of resonance frequencies and output power were deduced. 4. ANSYS is applied for the analysis of piezoelectric cantilever structures, solution of resonance frequencies were stated, meanwhile, the factor of proof mass, width and length of cantilevers and thickness of PZT were discussed.5. Circuit for signal magnified, commutated and low input voltage synchronous boost converter were designed and debugged. The experiments of random and sinusoidal vibration tests have been done.