Broadband vibration energy harvesting techniques

The continuous reduction in power consumption of wireless sensing electronics has led to immense research interests in vibration energy harvesting techniques for self-powered devices. Currently, most vibration-based energy harvesters are designed as linear resonators that only work efficiently with limited bandwidth near their resonant frequencies. Unfortunately, in the vast majority of practical scenarios, ambient vibrations are frequency-varying or totally random with energy distributed over a wide frequency range. Hence, increasing the bandwidth of vibration energy harvesters has become one of the most critical issues before these harvesters can be widely deployed in practice. This chapter reviews the advances made in the past few years on this issue. The broadband vibration energy harvesting techniques, covering resonant frequency tuning, multimodal energy harvesting, and nonlinear energy harvesting configurations are summarized in detail with regard to their merits and applicability in different circumstances.