Toward Broadband Vibration-based Energy Harvesting

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 paper reviews the advances made in the past few years on this issue. The broadband vibration-based energy harvesting solutions, covering resonance tuning, 2 multimodal energy harvesting, frequency up-conversion and techniques exploiting nonlinear oscillations, are summarized in detail with regard to their merits and applicability in different circumstances.

The benefits of Duffing-type nonlinearities and electrical optimisation of a mono-stable energy harvester under white Gaussian excitations

“…From equation (14) it can be seen that β has no influence on the relative velocity PDF and therefore cannot effect the power output of the device (as stated in [10] and [16]). However, the nonlinearity does affect the relative displacement PDF and can therefore be used to reduce the maximum displacement of the centre magnet without effecting the power output.…”

“…However, the nonlinearity does affect the relative displacement PDF and can therefore be used to reduce the maximum displacement of the centre magnet without effecting the power output. In [5] the maximum possible amplitude of the centre magnet was identified as one of the limiting factors with respect to device performance and equation (14) shows that the nonlinear spring term is beneficial in this respect.…”

“…Consequently, much effort has been directed towards the development of devices which are designed to work well over a larger bandwidth (reviews of which can be found in [13] and [14]). Of particular interest here is the findings shown in [15] where it was suggested that the introduction of Duffing-type nonlinearities into an SDOF electromagnetic device may help to extend its useful bandwidth.…”

An Energy conversion model for cantilevered piezoelectric vibration energy harvesters using only measurable parameters

“…[4][5][6][7] In this work, we are mainly concerned with piezoelectric energy harvesters (PEHs) because piezoelectricity is known to possess high energy conversion efficiency and ease of miniaturization. 7 Although many improved configurations for PEHs have been proposed to overcome the main issues of insufficient output power and narrow working frequency bandwidth, [8][9][10][11][12][13][14] cantilever-type PEHs with relatively low resonant frequencies have been more commonly employed so far either in unimorph or bimorph configurations. It is noted that cantilever-type PEHs still play a role as a reference when the performance of a newly developed PEH are to be compared.…”

On square-wave-driven stochastic resonance for energy harvesting in a bistable system

“…Early work on vibrational harvesting mechanisms primarily concentrated on harvesters operating within linear regimes, [1][2][3][4][5][6] after which the exploitation of nonlinear phenomena began to take over, principally because of the limited bandwidth offered by systems operating purely within the linear response region. Variations around the Duffing oscillator provide several interesting possibilities.…”