Development and experiments of a micro piezoelectric vibration energy storage device

According to the difficult replacement and poor endurance of the battery for wireless sensor network nodes, a micro piezoelectric vibration energy storage device was developed in this paper. The electric generating performance of the device was then tested on a self-made experimental system. It is shown that the developed energy storage device can collect effectively surrounding vibrations. What is more, the inherent frequency of the device can be expanded by adjusting the span between its two piezoelectric vibrators. It is also found that the output of the device depends badly on the external load resistance. With the increasing of load resistance, the output voltage increases while the output power increases first then decreases. The output power has an optimal associated load resistance. The output power achieves a maximum value 115.2 μW when the load resistance is 200 kΩ. With the energy storing circuit, the output electric energy of the device can effectively act as a power source for any low power micro electron devices such as wireless sensor network nodes. It is believed that this work may be practical for energy supplying of the low power micro electron devices.