| Piezoelectric cantilever with PZT is key component for vibration energy harvester. In this paper, we discussed the whole preparation process of piezoelectric cantilever,with focused on PZT ferroelectric film preparation and MEMS based fabrication technology.The PZT ferroelectric film was prepared by Sol-Gel method on Pt/Ti/SiO2/Si base with domestic reagents. The factors that would make impact of precursor Sol were discussed respectively, including concentration, pH, and temperature. We also studied the thermal and annealing process and their influence on the film. With the ultimately determined solution ,we made PZT ferroelectric thin film with thickness of 2μm. The Scanning Electron Microscope and X-ray diffraction were used to analyze the composition and micro structure of the film. The TR66A Tester was used to analyze the hysteresis loop. With analysis of crystal structure and electrical properties, finding that Pt/Ti bottom electrode and sufficient annealing treatment could enhance (111) preferred crystallographic orientation, which shows better ferroelectric properties. The Pr of the sample is 19.94μC/cm2,Ec is 11.60 kV/cm.Design and fabricate a MEMS-based piezoelectric generator using self-prepared PZT film. The main part of the generator is a trapezoidal shape cantilever with Ni metal mass on the free end. The design is in order to improve power generation efficiency and reduce the resonant frequency. The whole fabrication process of MEMS-based techniques including wet chemical etching, RIE dry etching and UV-LIGA is introduced. The size of the cantilever is length×W1×W2= 2000μm×750μm×500μm. By being measured on the vibration testing system, the generator reaches the first resonant mode at 155.0 Hz. With 1g acceleration, the output peak-peak voltage is 984 mV. In addition, we also investigate the energy harvesting application from ultrasonic vibration in fluid environments by a specially developed waterproof piezoelectric cantilever generator. |
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