Low-frequency and broadband vibration energy harvester driven by mechanical impact based on layer-separated piezoelectric beam

Abstract

Vibration energy harvesting is to transform the ambient mechanical energy to electricity. How to reduce the resonance frequency and improve the conversion efficiency is very important. In this paper, a layer-separated piezoelectric cantilever beam is proposed for the vibration energy harvester (VEH) for low-frequency and wide-bandwidth operation, which can transform the mechanical impact energy to electric energy. First, the electromechanical coupling equation is obtained by the Euler-Bernoulli beam theory. Based on the average method, the approximate analytical solution is derived and the voltage response is obtained. Furthermore, the physical prototype is fabricated, and the vibration experiment is conducted to validate the theoretical principle. The experimental results show that the maximum power of 0.445 mW of the layer-separated VEH is about 3.11 times higher than that of the non-impact harvester when the excitation acceleration is 0.2 g. The operating frequency bandwidth can be widened by increasing the stiffness of the fundamental layer and decreasing the gap distance of the system. But the increasing of operating frequency bandwidth comes at the cost of reducing peak voltage. The theoretical simulation and the experimental results demonstrate good agreement which indicates that the proposed impact-driving VEH device has advantages for low-frequency and wide-bandwidth. The high performance provides great prospect to scavenge the vibration energy in environment.

Modeling and experiment of vibro-impact vibration energy harvester based on a partial interlayer-separated piezoelectric beam

“…Comparing with the previous research work (Cao et al, 2019c), it is found that the first and second resonant frequencies of the partial separated VEH are smaller than that of the complete separated VEH. The results show the advantages of lower frequency and broad bandwidth energy harvesting.…”

“…However, conventional vibro-impact VEHs need much more space to assemble the driving system, impactor or magnet, that is disadvantageous to expand the engineering applications especially for the integration with micro-electro-mechanical system. In order to overcome these issues, the authors (Cao et al, 2019c) proposed a layer-separated vibration energy harvester based on vibro-impact model, where there is no need any other impactor. The results show that it's realizable to scavenge the vibration energy.…”

Design and performance enhancement of a force-amplified piezoelectric stack energy harvester under pressure fluctuations in hydraulic pipeline systems

“…To obtain the electromechanical coupling equation of the enhanced PFEH, the piezoelectric stack is regarded as a single degree-of-freedom system, see Figure 3(e). As aforementioned, the dynamic equation of the piezoelectric stack under the excitation force 𝐹 𝑜𝑢𝑡 can be expressed as 𝑚 𝑆 𝑦̈+ 𝐶 𝑆 𝑦̇+ 𝐾 𝑆 𝑦 = 𝐹 𝑜𝑢𝑡 (11) in which 𝑦 is the longitudinal vibration displacement of the piezoelectric stack, 𝐶 𝑠 is a damping coefficient of the system, 𝑚 𝑆 = 𝑁𝜌𝑑𝑆 3…”

“…Vibrationbased energy harvesting (VEH) techniques, which can transform ambient mechanical energy from external sources to electric energy, is an ideal solution to drive small-scale and wireless devices, like those used in wearable electronics and wireless sensors. In recent years, a plenty of research studies have devoted great efforts on different technologies of VEH, and various transduction mechanisms have been used, such as electrostatic [1][2][3], electromagnetic [4][5][6], piezoelectric [7][8][9][10][11] and ferroelectric approaches [12][13][14][15]. On the other hand, many structure forms have been proposed to improve and enhance the performance of vibration energy harvesters, including bi-stable [16][17][18], multi-stable [19][20][21][22] and multi-degree models [23][24][25].…”

A review of nonlinear piezoelectric energy harvesting interface circuits in discrete components

“…The mechanical base structure is used to collect the vibration energy and transfer it to the piezoelectric elements. Different types of nonlinear structures, e.g., impact structures [23][24] , frequency up-conversion [25] , monostable structures [26] , and multi-stable structures [27][28][29] , have been developed to broaden the working bandwidth of piezoelectric energy harvesters (PEHs) [30] so as to improve the total harvested energy and environment serviceability [31][32][33] . Researchers have also concentrated on improving piezoelectric materials to enhance the dielectric property, storage capacity, stability, and piezoelectricity [34][35][36][37][38][39] .…”