Performance investigation of a nonlinear vibrational energy harvester with band limited noise

In the field of Energy Harvesting, it has been demonstrated that, under the proper conditions, nonlinear configurations of the harvester can provide better performance, compared to linear resonant oscillators; the performance is quantified in terms of the amount of energy extracted from environmental mechanical vibrations. In this paper the authors present the preliminary results of investigations on a system for energy harvesting from wideband vibrations, using a nonlinear Snap-Through Buckling configuration and two piezoelectric transducers, placed at the stable minima of the potential energy function that underpins the dynamics. The device is demonstrated to be capable of scavenging energy from band limited vibration sources in the range 0.5-15 Hz, but could be exploited up to 20 Hz with an acceptable loss of efficiency. The bandwidth of the device is compatible with applications where the vibrations occur at low frequencies e.g. In the case of a running human. The device is seen to generate power up to 160 μW in case of a noise limited at 15 Hz; the power is sufficient to operate a standard wireless sensor node. The conversion efficiency of the harvester is about 12%.