Smart wireless sensor network powered by random ambient vibrations

Over the past years, there has been a lot of efforts on the development of wireless sensor networks. However, the major constraint on broad application of wireless sensor network is still the battery lifetime on the wireless sensor nodes. In this paper, a complete power efficient sensor network system will be presented, and energy harvesting from ambient vibrations to further extend battery lifetime will also be detailed. The consideration on the power efficient design will take all aspects from hardware to network protocols. A tunable resonant frequency power harvesting device in cantilever beam form which will shift its resonant frequency to match that of the external vibrations adapting to the random ambient vibrations will also be presented to gain high energy harvesting efficiency from random ambient vibrations. With all the power saving and the power harvesting features implemented in the wireless sensor network design, years of battery lifetime on the sensor node could be expected. The experiment verification of the system and also scenario analysis on battery lifetime will also be presented in this paper.