Wideband, low-frequency springless vibration energy harvesters: part II

Abstract

This paper concludes a two-part investigation of a novel architecture for vibration energy harvesting (VEH), the springless VEH. In this part, we study vertical springless electromagnetic VEHs where the direction of motion is aligned with the gravitational field. Experimental results show the existence of three topologies in the response of vertical springless VEHs; linear, single-impact, and double-impact. A model, encompassing all three topologies, was developed and validated by comparison to experimental results. We found that vertical springless VEHs demonstrate low frequency harvesting (<20 Hz), widebeand harvesting (bandwidths up to = BW 11.2 Hz), and an optimal output power of P = 7.52 mW at a base acceleration of 0.6 g. While horizontal springless VEHs typically offer more output power, the single-impact regime of the vertical springless VEHs offers the simultaneous advantages of wider harvesting bandwidths at lower operating frequencies.

Frequency tunable electromagnetic vibration energy harvester using piecewise linear nonlinearity

“…As is common with many of these systems, this system did not show high vibration performance for all excitation conditions, namely the reverse frequency sweep. Bendame et al [24,25] also proposed a springless VEH with stoppers positioned at the ends of the harvester. In this system, a nonlinearity in the form of a mechanical stopper is introduced into the traditional linear system creating a piecewise-linear (PWL) nonlinear oscillator to change the dynamics of the system.…”