Design and Development of Low Frequency Vibration Energy Harvester for Wireless Sensor Networks

Motivated by wireless sensor networks technology for surveillance and tracking of animals, the energy harvesters are designed and fabricated. Since energy harvester is designed to harvest low frequency seismic noise, electromagnetic principle will be used in the harvester. It can be noted that structure undergoes small strains and thus piezoelectric based harvester is not suitable for low strains. Folded beam structure, circular spiral and square spiral geometries have been considered for the design of vibration energy harvester. Folded beam structure has been tested against experiments and it agrees well with the simulated results. Simulations performed on circular and square spiral geometries show that the first natural frequency is about 0.2 Hz. Square coil was manufactured and tested which gave natural frequency of 0.29 Hz.