Toward Broadband Vibration-based Energy Harvesting

TLDR

The dramatic drop in power consumption of integrated circuits has spurred interest in harvesting ambient vibrations as a battery‑free power source, yet conventional linear resonator harvesters lose performance when excitation frequencies shift, a common issue with the frequency‑varying or broadband nature of real vibrations. The study aims to broaden the bandwidth of vibration‑based energy harvesters to address the mismatch between resonant frequencies and variable ambient excitations. The review surveys broadband harvesting strategies—including resonance tuning, multimodal harvesting, frequency up‑conversion, and nonlinear oscillation techniques—detailing their merits and suitability across different scenarios.

Abstract

The dramatic reduction in power consumption of current integrated circuits has evoked great research interests in harvesting ambient energy, such as vibrations, as a potential power supply for electronic devices to avoid battery replacement. Currently, most vibration-based energy harvesters are designed as linear resonators to achieve optimal performance by matching their resonance frequencies with the ambient excitation frequencies a priori. However, a slight shift of the excitation frequency will cause a dramatic reduction in performance. Unfortunately, in the vast majority of practical cases, the ambient vibrations are frequency-varying or totally random with energy distributed over a wide frequency spectrum. Hence, developing techniques to increase the bandwidth of vibration-based energy harvesters has become the next important problem in energy harvesting. This article reviews the advances made in the past few years on this issue. The broadband vibration-based energy harvesting solutions, covering resonance tuning, multimodal energy harvesting, frequency up-conversion, and techniques exploiting non-linear oscillations, are summarized in detail with regard to their merits and applicability in different circumstances.