A novel up-converting mechanism based on double impact for non-linear piezoelectric energy harvesting

Abstract

In this paper we show the importance of double impact in an up-converting mechanism by usinga resonant low-frequency driving beam across a high-frequency piezoelectric beam, to enhancethe electrical output power in a vibration energy harvesting (VEH) system suitable for ambientvibrations. The main advantage of this device is its nearly constant output voltage betweenimpacts compared to other VEH systems using up-converting mechanisms whose outputvoltages decay abruptly after impact. With the proposed design, the optimum electrical load ofthe system is substantially lower compared to traditional low-frequency VEH systems. Thismechanism improves the energy transfer to some transducers and electronic interfaces with lowinput impedances, attaining optimal efficiency.