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To improve the harvesting performance of bi-stable energy harvesters, this paper proposes a novel bi-stable piezoelectric energy harvester which consists of a piezoelectric cantilever beam with a tip magnet and a movable magnet. The movable magnet connects to the base through a spring and is allowed to move along the spring compression direction. T...
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... to the power outputs, Fig.8 shows that when the amplitude is lower than 0.14, the SBEH generates higher power output and presents higher efficiency than the TBEH under the situation of weak excitation level. The ratio of the power output by the SBEH to that of the TBEH within this amplitude range is listed as Table 2. It is obvious that the SBEH can improve the harvesting performance significantly, up to about 29 times the TBEH when A=0.04 and the least 4 times when A=0.12. ...Similar publications
Taking into account the gravitational potential energy of the piezoelectric energy harvester, the size effect, and the rotary inertia of tip magnet, a more accurate distributed parametric electromechanical coupling equation of tristable cantilever piezoelectric energy harvester is established by using the generalized Hamilton variational principle....
This paper focuses power generation and nonlinear dynamic behaviors on a new bistable piezoelectric-electromagnetic energy harvester. Three different kinds of piezoelectric cantilever beam structures, which include the monostable piezoelectric cantilever beam, the bistable piezoelectric cantilever beam with spring and magnet, and the bistable piezo...
In order to make a piezoelectric vibration energy harvester collect more energy on a broader frequency range, nonlinearity is introduced into the system, allowing the harvester to produce multiple steady states and deflecting the frequency response curve. However, the harvester can easily maintain intra-well motion rather than inter-well motion, wh...
Citations
... Researchers such as Wang et al. 23 have examined TPVEHs influenced by geometric nonlinearity and gravitational effects, highlighting the formation of asymmetric potential energy wells that facilitate easier transitions between vibrational states under minimal excitation. Subsequent works by Yang and Towfighian 24 and Li et al. 25 introduced a bistable energy harvester with a movable magnet designed to ease the snap-through mechanism. Furthermore, Zhou et al. 26 proposed a flexible, nonlinear, bistable energy harvester capable of generating tunable potential wells for increased power output. ...
This study introduces an innovative asymmetric tri-stable piezoelectric vibration energy harvester (ATPVEH) augmented with an elastic base (EB), aimed at optimizing energy capture from low-orbit vibrations. This design incorporates a uniquely configured asymmetric tri-stable piezoelectric cantilever beam, positioned within a U-shaped block that is further enhanced by an elastic base. A strategically placed spring (kf)–mass (Mf) system, situated between the U-shaped block and the constrained end of the beam, significantly boosts the vertical displacement of the beam during vibrational events. We developed a dynamic model for the ATPVEH+EB utilizing Lagrange’s equations, exploring the impact of various factors—including the asymmetry of the potential well, the stiffness of the elastic base, the mass of the spring–mass system, and the load resistance—on the system’s nonlinear dynamic responses. Our findings indicate that the ATPVEH+EB facilitates more efficient energy harvesting from low-orbit vibrations, demonstrating dual response peaks across its operational frequency spectrum. Notably, the displacement and output voltage amplitudes of the ATPVEH+EB can be enhanced by increasing mf or decreasing kb, whereas the peak output power transitions toward a lower frequency range as the load resistance escalates. Both theoretical analyses and numerical simulations corroborate the ATPVEH+EB’s superior performance in harvesting energy within low-orbit vibrational environments.
... To improve the performance, a two-span beam that has buckled and flexed piezoelectric film is used. Li et al. 29 proposed a bi-stable piezoelectric energy harvester which consists of a piezoelectric cantilever beam with a tip magnet and a movable magnet. The movable magnet is attached to the base by a spring and is free to move in the direction of the spring compression. ...
Many electrical devices can be powered and operated by harvesting the wasted energy of the surroundings. This research aims to overcome the challenges of output power with a sharp peak, small bandwidth, and the huge dimensions of the piezoelectric energy harvesters relative to the output power. The aforementioned challenges motivated us to investigate the effect of nonlinearity in the shape (tapered and straight cross-section area) as well as the fixation method (the number of fastened ends) to determine the optimal design with high output power and wide working frequency. This research proposes a novel piezoelectric energy harvester array, where each beam is made up of three fixed beams that are joined together by a center mass. The proposed design produces an output power of 35 mW between 25 and 40 Hz. The output power of the proposed design is 3.24 times more than the conventional designs. The recommended approach is simulated utilizing finite element analysis FEA. Analytical and experimental methods validate the proposed FEA, which exhibits excellent agreement.
... Reference [9] introduced a through mechanism using a spring in BSEHs, where the spring stiffness significantly affected the output. The snap-through mechanism enabled the beam to operate more efficiently across broader frequency ranges. ...
Unwanted vibrations cause discomfort and affect the accuracy of the machinery. Vibrations of low frequency (<30 Hz) are usually inutile. Various researchers focus on harvesting and enhancing energy output through low-frequency vibrations. This paper focuses on improving energy harvesting from low-frequency vibration sources through taper shape (TAP) bistable beam fabricated using thin Piezoelectric Polyvinylidene fluoride (PVDF) film sandwiched between thin copper and aluminium films on both sides. Voltage power output through a PVDF film depends on the film’s strain distribution; hence, in this study, five different beam designs are studied for strain distribution through the ANSYS workbench. Further, an experimental harmonic analysis study for voltage output is performed on rectangular beam (RECT) and TAP beam for both straight and bistable configuration using three different harmonic input conditions, which concluded that the voltage output for the TAP beam is much more than that of the RECT beam, with a much more significant voltage output increase in bistable conditions for all three harmonic input conditions.
... To enhance the bandwidth and energy efficiency of EHs, researchers have explored nonlinear mechanisms such as bi-stable [21,22] and tri-stable vibration mechanisms [23][24][25], and array beams in series and parallel connection [26,27]. These nonlinear mechanisms are suitable for harvesting energy sources with frequencies fluctuating within a limited range. ...
We propose a novel magnetic energy harvester (MEH) with multiple resonance modes. The MEH consists of low-frequency and high-frequency piezoelectric cantilevers connected by a coupling beam. Theoretical modeling, simulation, and experiments were conducted to validate the multiple resonance phenomenon. The results from these investigations are consistent with each other. It is evident that the internal coupling (IC) effect resulting from the coupling beam facilitates significant voltage outputs from both cantilevers at their respective resonant frequencies, i.e. the low-frequency beam (LFB) resonates at the resonant frequency of the high-frequency beam (HFB), resulting in a remarkable 122% increase in the output voltage. Conversely, the HFB resonates at the resonant frequency of the LFB, leading to an astounding 1200% increase in the output voltage. As a result of the IC phenomenon, the operating frequency bandwidth for harvesting an output voltage of more than 1 V in the LFB has been extended by 35.3%, while that of the HFB for capturing an output voltage of more than 0.5 V has been extended by 62.5%. Additionally, the coupling effect significantly enhances the power output of the MEH.
... The dynamic response under random excitation proved that the FBEH has a smaller threshold for snap-through. Several illuminating investigations of variable potential barriers have been conducted around similar piezoelectric BEH-VP [Shan et al., 2018;Li et al., 2020;Fan et al., 2021;Chen et al., 2022;Deng et al., 2022]. Apart from the orthogonal BEH-VP 2450035-3 Int. ...
To achieve broadband energy harvesting under weak excitations, this paper comprehensively investigates a novel tri-magnet levitating bistable electromagnetic energy harvester with variable potential wells (BEEH-VP). The bistable nonlinear mechanism is realized using the single-sided bipolarity of the ring magnets. Auxiliary springs are integrated into the ring magnets to dynamically self-adjust the spacing of the ring magnets, causing variable potential wells. The analytical model of BEEH-VP is derived and verified experimentally. The performance of the proposed BEEH-VP is compared with that of the bistable electromagnetic energy harvester featuring fixed potential wells (BEEH-FP). The comparative results clearly demonstrate that the BEEH-VP exhibits superior capabilities in terms of energy output under weak excitation and possesses a broader frequency bandwidth. Bifurcation analysis for the excitation conditions reveals that the proposed structure features complex dynamic behaviors, such as intra-well, chaotic, harmonic inter-well, and subharmonic inter-well vibrations. In comparison to BEEH-FP, BEEH-VP requires lower acceleration to perform the snap-through and has a larger vibration amplitude, facilitating improved output performance.
... Zhou et al. [28] presented a nonlinear flexible BEH, and its simulation results demonstrated that the proposed harvester has a smaller threshold for snap-through and thus generates larger output power. Li et al. [29] designed a novel spring-connected BEH, and numerical simulations showed that its potential barrier was reduced and snap-through triggered easily under lower excitation. ...
... Constructions with moving magnets have also been featured in other works. Xinxin et al. [35] proposed an energy harvester built of a piezoelectric cantilever beam with a tip magnet and a movable magnet connected by a spring to the housing, which broadened operating bandwidth and improved harvesting power. Zhou et al. [36] had the same goal when he introduced a bi-stable energy harvester based on two flexible beams with a variable potential energy function. ...
Dynamical systems for kinetic energy harvesting have recently been designed that use nonlinear mechanical resonators and corresponding transducers to create electrical output. Nonlinearities are important for providing a broadband input frequency efficiency, which is necessary to ensure that the output voltage is at a satisfactory level in the case of a variable ambient vibration source. In this paper, we analyze the dynamics of such a system with the additional possibility of a switching potential barrier in the nonlinear resonator. In order to improve the effectiveness of the energy harvester, we numerically test the possibility of using abrupt changes in the system parameters. We analyze the voltage output for various frequencies of both the harmonic excitations and the potential barrier switching. In a range that includes low and high switching frequencies of potentials, the periodic solutions dominate in the bifurcation diagrams. With regard to the large switching frequency, the effective values of the voltage at the piezoelectric electrodes are significantly reduced. The highest effective values of the voltage that are induced at the piezoelectric electrodes are observed when the chaotic solutions appear due to their specific ability to pass the potential barrier for relatively small excitation. The results also show that mechanical damping with high-enough magnitudes minimize the influence of the transient states caused by the switching potentials.
... At present, rotational energy harvesters based on the piezoelectric effect, the electromagnetic effect, the triboelectric effect and the electrostatic effect are extensively explored and investigated. In addition, various smart structures and physical principles like nonlinearity [1][2][3][4][5][6][7], multimode array [8][9][10][11] and frequency tuning method [12][13][14][15][16] have successfully been applied to enhance energy harvesting efficiency. ...
Piezoelectric energy harvesters (PEHs) have attracted great attention to solve the power supply issue of wireless sensors in rotational motions. PEHs based on smart structures and physical principles have been widely investigated. Currently, the frequency bandwidth and the energy harvesting efficiency are two urgent issues to be solved in practical applications. Benefiting from the advantages of magnet-induced nonlinearity and frequency up-conversion, this paper proposes array PEHs for rotational energy harvesting. To reveal their broadband mechanisms, the corresponding theoretical model is established according to Lagrange equations. Then, effects of the gap distances, frequency up-conversion and installation configurations on the dynamic characteristics of PEHs are theoretically analyzed. In addition, experimental validations are conducted to investigate these effects under different rotational speeds. Experimental results demonstrate that the gap distance of 8 mm leading to a large driving force is better for improving energy harvesting performance than other gap distances. Furthermore, the frequency up-conversion phenomena are validated to widen the effective frequency bandwidth. The gravity effect on the PEHs for the forward and headstand configurations is noticed, simultaneously qualitatively verifying the gravity coefficient in the derived mathematical model. In summary, this paper presents a high-efficiency array PEHs for rotational energy harvesting with in-depth theoretical analyses, providing insights into the broadband PEH design in rotational motions.
... Constructions with moving magnets have also been featured in other works. Xinxin et al. [35] proposed an energy harvester built of a piezoelectric cantilever beam with a tip magnet and a movable magnet connected by a spring to the housing, which broadened operating bandwidth and improved harvesting power. Zhou et al. [36] had the same goal when he introduced a bi-stable energy harvester based on two flexible beams with a variable potential energy function. ...
Dynamical systems for kinetic energy harvesting have recently been designed that use nonlinear mechanical resonators and corresponding transducers to create electrical output. Nonlinearities are important for providing a broadband input frequency efficiency, which is necessary to ensure that the output voltage is at a satisfactory level in the case of a variable ambient vibration source. In this paper, we analyze the dynamics of such a system with the additional possibility of a switching potential barrier in the nonlinear resonator. In order to improve the effectiveness of the energy harvester, we numerically test the possibility of using abrupt changes in the system parameters. We analyze the voltage output for various frequencies of both the harmonic excitations and the potential barrier switching. In a range that includes low and high switching frequencies of potentials, the periodic solutions dominate in the bifurcation diagrams. With regard to the large switching frequency, the effective values of the voltage at the piezoelectric electrodes are significantly reduced. The highest effective values of the voltage that are induced at the piezoelectric electrodes are observed when the chaotic solutions appear due to their specific ability to pass the potential barrier for relatively small excitation. The results also show that mechanical damping with high-enough magnitudes minimize the influence of the transient states caused by the switching potentials.
... As a result, broadening the operating bandwidth of a MEMS PEH can effectively improve the energy harvesting efficiency. Many research groups have proposed various nonlinear mechanisms to realize continuous bandwidth broadening, such as mono-stable, 19 bi-stable, 20,21 and frequency up-conversion mechanisms. [22][23][24][25] These nonlinear PEHs are adapted to the scenarios that the frequencies of vibration sources fluctuate in a limited range. ...
In this paper, a multi-frequency vibrational piezoelectric energy harvester (PEH) with a dual-microcantilever coupled structure based on the internal resonance effect is proposed. The device consists of a low-frequency cantilever and a high-frequency cantilever with an integer multiple of resonant frequencies connected by a clamped–clamped coupling beam. The internal resonant PEH (IR-PEH) is prepared by the microelectromechanical systems piezoelectric thick-film process based on the flexible thin metal substrate. The output performance of the proposed PEH device is greatly improved by taking advantages of the internal coupling structure and the piezoelectric thick-film microfabrication process. Under the excitation acceleration of 2 g, the maximum power output of IR-PEH reaches 424.6 μW at 190 Hz and 108.8 μW at 365 Hz, which increases by 35% of the power output due to the internal resonance coupling comparing with the PEH without the coupling effect. The corresponding power densities of IR-PEH reach 6.3 and 1.6 mW/cm ³ , respectively. This IR-PEH configuration induces the competitive advantages of good performance, wide bandwidth, and small volume, which can be potentially employed as a power source for low power wireless sensing nodes.
