A design of mass-spring type piezoelectric energy harvesting

This study introduces an experimental power generation system based on piezoelectric energy conversion for low-power applications such as wireless sensor nodes. Piezoelectric Transducers (PZTs) are especially suitable for energy harvesting from the ambiance. A PZT is able to produce an open-circuit voltage at a hundred-volt level. However, the acquired current may be achieved on a nano-micro scale. Therefore, PZT Energy Harvesters (PEH) have a very limited power generation capability. In order to generate greater output power, a series of PZTs should be applied to a PEH with a proper electrical connection. In this paper, PEH is presented with a novel circuit topology to increase the output power. The experimental system uses 20 diaphragm type PZTs with a spring of 15 cm mounted at the center of each transducer. The required vibration is produced using a spring-mass structure of each PZT. Mass-spring structure vibrates by the wind effect. The maximum output power of the presented experimental generator at a nominal wind speed of 12 m/s is around 10.8 mJ. The obtained results indicate that the proposed experimental generator is suitable for low-power applications, and the output power of the generator can be increased by using more PTZs connected via circuit topology.