Experiment on wireless sensor vibration energy collection

Based on piezoelectric phenomena, a vibration energy harvesting (EH) solution for a self-powered wireless sensor was investigated experimentally. The physical principle of the vibration EH was presented. A preliminary AC-DC module with a full bridge rectification circuit and a filtering circuit was designed. A piezoelectricity cantilever's first bending mode was excited and the output voltage and energy were measured. The experimental results show that the output DC voltage is proportional to the load impedance under 0.35 MΩ. The harvested power has a maximum value attributed to impedance matching. BaTiO3 used in this paper has a large output impedance(>10 MΩ), the maximum harvested power is 75 μW. The saving of harvested energy in random vibration condition need to be studied fourthly. The model studied in this paper can be used for a mW DC generator design.