Vibration Energy Harvesting Device Research Articles

Effects of Mechanical and Electrical Topologies on Piezoelectric Stacked Energy Harvesting in Vehicle Suspensions

The choice of mechanical and electrical topologies can affect piezoelectric energy harvesting efficiency, but the problem of achieving high-efficiency energy conversion in energy harvesters stacked as cantilevers has not been perfectly solved. This study focuses on the topology of piezoelectric elements in a stacked vehicle suspension vibration energy harvesting device. Through theoretical analysis, the stress expressions of the excited and driven elements are derived. The stress of the piezoelectric elements is affected by the positions of the connection and excitation points. A stress model was established for a four-piece piezoelectric element connected by a thin light rod in ANASYS. The simulation results show that the average stress in the piezoelectric bending element model is maximum when the excitation and connection points are located at both ends of the free end. Compared with the middle position of the free end of the piezoelectric element, the average stress of the model is increased by 92.904%. Considering the difference in voltage generated by piezoelectric elements, four kinds of electrical topology are designed and analyzed experimentally. When the driven elements are connected in parallel and then connected in series with the excited element, the output power varied the least with the change of load resistance. The system produces a high power and offers a wide selection of load resistors. When the load is 26 kΩ, a single set of four piezoelectric elements produces 86.407 mW of output power.

Design a low-frequency vibration energy harvesting device based on a square spiral beam local resonant phononic crystal

Self-powered miniature wireless sensors play a crucial role in Internet of Things technology. Harvesting low-frequency environmental vibrations to achieve self-powering of sensors is a current hot topic in research. In this study, a square spiral beam local resonant phononic crystal is designed for low-frequency vibrational energy harvesting. Initially, the bandgap and vibrational modes of an ideal phononic crystal at infinite period are analyzed by the finite element method; the possibility of using the structure to harvest vibrational energy is explored. Subsequently, a PnC plate model with a unit cell is built, and its vibrational modes are analyzed, verifying that it possesses similar vibrational properties. Following this, a piezoelectric vibration energy harvesting device is assembled and its energy harvesting performance is analyzed. Numerical simulations indicate that the designed device can achieve a maximum power density of 52.14 μW/cm2. Physical experiments validate the excellent energy harvesting performance of the device. The device offering a new option for designing self-powered devices for wireless miniature sensors.

Dynamic analysis of a novel multilink-spring mechanism for vibration isolation and energy harvesting

Due to technical limitations, existing vibration isolation and energy harvesting (VIEH) devices have poor performance at low frequency. This paper proposes a new multilink-spring mechanism (MLSM) that can be used to solve this problem. The VIEH performance of the MLSM under harmonic excitation and Gaussian white noise was analyzed. It was found that the MLSM has good vibration isolation performance for low-frequency isolation and the frequency band can be widened by adjusting parameters to achieve a higher energy harvesting power. By comparison with two special cases, the results show that the MLSM is basically the same as the other two oscillators in terms of vibration isolation but has better energy harvesting performance under multistable characteristics. The MLSM is expected to reduce the impact of vibration on high-precision sensitive equipment in some special sites such as subways and mines, and at the same time supply power to structural health monitoring devices.

Mechanical Vibration Energy Harvesting and Vibration Monitoring Based on Triboelectric Nanogenerators

Mechanical equipment is ubiquitous in industrial production, and the vibration energy generated by its operation usually cannot be effectively harvested, resulting in huge energy waste. Meanwhile, real‐time monitoring of machine operation can be achieved by collecting vibration information. Indeed, vibration energy harvesting and vibration monitoring are of great significance for the development of green energy and machine fault diagnosis. As an emerging power generation technology, triboelectric nanogenerator (TENG) has shown extraordinary potential in the field of vibration energy harvesting and vibration monitoring. First, the theoretical basis, working modes, and triboelectric materials are described. Then, TENG devices for vibration energy harvesting are classified and introduced based on the structural characteristics, and the main advantages and disadvantages are compared. Furthermore, the current research progress of a self‐powered vibration monitoring system based on TENG is introduced. Finally, the shortcomings of triboelectric nanogenerators in this field are analyzed and summarized, and future research directions and application scenarios are prospected.

Investigative Study of the Effect of Damping and Stiffness Nonlinearities on an Electromagnetic Energy Harvester at Low-Frequency Excitations

Ambient vibration energy is widely being harnessed as a source of electrical energy to drive low-power devices. The vibration energy harvester (VEH) of interest employs an electromagnetic transduction mechanism, whereby ambient mechanical vibration is converted to electrical energy. The limitations affecting the performance of VEHs, with an electromagnetic transduction structure, include its operational bandwidth as well as the enclosure-size constraint. In this study, an analysis and design of a nonlinear VEH system is conducted using the Output Frequency Response Function (OFRF) representations of the actual system model. However, the OFRF representations are determined from the Generalised Associated Linear Equation (GALE) decompositions of the system of interest. The effect of both nonlinear damping and stiffness characteristics, to, respectively, extend the average power and operational bandwidth of the VEH device, is demonstrated.

Integrated device for multiscale series vibration reduction and energy harvesting

A multi-degree-of-freedom device is proposed, which can achieve efficient vibration reduction as the main objective and energy harvesting as the secondary purpose. The device comprises a multiscale nonlinear vibration absorber (NVA) and piezoelectric components. Energy conversion and energy measurement methods are used to evaluate the device performance from multiple perspectives. Research has shown that this device can efficiently transfer transient energy from the main structure and convert a portion of transient energy into electrical energy. Main resonance and higher-order resonance are the main reasons for efficient energy transfer. The device can maintain high vibration reduction performance even when the excitation amplitude changes over a large range. Compared with the single structures with and without precompression, the multiscale NVA-piezoelectric device offers significant vibration reduction advantages. In addition, there are significant differences in the parameter settings of the two substructures for vibration reduction and energy harvesting.

A hybrid piezoelectric-electromagnetic energy harvester used for harvesting and detecting on the road

At present, some piezoelectric energy harvesters (PEH) have been widely used in various small wireless electronic devices and micro intelligent sensing devices for self-power supply, but PEH still needs to be further improved in the effective acquisition of road vibration energy at low frequency (<10 Hz), especially at ultra-low frequency (<5 Hz) and broadening the capture energy band. Based on this, this paper proposes a hybrid piezo-electromagnetic road vibration energy harvesting device -TPEH (Triple piezoelectric energy harvester) suitable for road deceleration belts. Spring is introduced as the key to improve the efficiency of energy harvesting. Firstly, the vibration environment of the deceleration belts is surveyed, and then the influence of different K, frequencies, vehicle types and impedance on the energy capture effect is observed in the experiment. The experimental results show that: first of all, K = 20 N/kg main spring has the best resilience; Secondly, with the increase of excitation frequency from 0 Hz to 10 Hz, the maximum peak voltage of TPEH increases from 5.7V to 31.2V, and reaches the full bandwidth in the low frequency range of 0–10 Hz, especially the frequency band widening in the range of 0–1 Hz has ma de a breakthrough. Then, the total output power of TPEH reaches a maximum of 10.29 mW under the optimal load condition of 10 kΩ. Finally, TPEH is applied to the speed strip of a local road section. Through reasonable distribution of vibration signals, TPEH could accurately wireless communication module.

Liquid Vibration Energy Harvesting Device Using Ferrofluids.

Mechanical vibrations can be effectively converted into electrical energy using a liquid type of energy harvesting device comprised of a ferrofluid and a permanent magnet-inductor coil assembly. Compared to solid vibration energy harvesting devices, the liquid nature of the ferrofluid overcomes space conformity limitations which allow for the utilization of a wider range of previously inaccessible mechanical vibration energy sources for electricity generation and sensing. This report describes the design and the governing equations for the proposed liquid vibration energy harvesting device and demonstrates vibration energy harvesting at frequencies of up to 33 Hz while generating up to 1.1 mV. The proposed design can continuously convert mechanical into electrical energy for direct discharge or accumulation and storage of electrical energy.

Self‐biased magnetoelectric composite for energy harvesting

AbstractThe wireless sensor network energy supply technology for the Internet of things has progressed substantially, but attempts to provide sustainable and environmentally friendly energy for sensor networks remain limited and considerably cumbersome for practical application. Energy harvesting devices based on the magnetoelectric (ME) coupling effect have promising prospects in the field of self‐powered devices due to their advantages of small size, fast response, and low power consumption. Driven by application requirements, the development of composite with a self‐biased magnetoelectric (SME) coupling effect provides effective strategies for the miniaturized and high‐precision design of energy harvesting devices. This review summarizes the work mechanism, research status, characteristics, and structures of SME composites, with emphasis on the application and development of SME devices for vibration and magnetic energy harvesting. The main challenges and future development directions for the design and implementation of energy harvesting devices based on the SME effect are presented.

Mechanical energy conversion to electricity through periodically stress-induced martensitic transformation in Co-Ni-Ga

We anticipate and demonstrate experimentally the mechanical-to-electrical energy conversion through the variation of magnetization resulting from a periodical stress-induced martensitic transformation in the single crystalline Co-Ni-Ga ferromagnetic shape memory alloy. Dynamic loading in a stress-induced austenite-martensite two-phase state was performed with the peak-to-peak strain amplitude from 0.002 to 0.024 in a frequency range of 25 - 150 Hz. A reproducible superelastic behavior occurred at all frequencies. Alongside this remarkable result, we found that the electrical power output depends quadratically on the peak-to-peak strain. This study suggests a new route for the development of broad-band vibration energy harvesting devices.

Research on pendulum-type tunable vibration energy harvesting

Sensors, as the most common electronic devices in electromechanical systems, are often scattered in huge numbers in the environment to be monitored. When the power of the sensor comes from batteries, the long-term continuous power supply and the replacement of the battery under severe working conditions are the main problems. Compared with other energy sources, vibration energy is more universal and stable, so it is often harvested and utilized by specific devices. Most of the traditional vibration energy harvesting devices have the disadvantage that the natural frequency cannot be tuned, which will lead to significant decline of energy harvesting efficiency when the environmental frequency changes. Although some energy harvesting devices are with tunable nature frequency, the linearity is relatively poor when tuning. In order to solve the problems above, a structural model of an electromagnetic energy harvesting device using motion of a pendulum rod is constructed. Natural frequency characteristics and electromagnetic field finite element simulation analysis of the model are carried out. An experimental platform of the device and a corresponding electric energy storage circuit are designed and built. Simulation and experimental results show that the natural frequency of the device can be tuned linearly in the range of 7 Hz–13.5 Hz. The maximum induced electromotive force that the device can output is 1.37 V and the maximum power is 521 mW. When the device is connected to the electric energy storage circuit, the device can output 3.4 V DC voltage. Compared with the traditional devices that can only harvest energy efficiently from a single vibration frequency, the advantage of this model is that its natural frequency can be adjusted to adapt to different ambient vibration frequencies and the linearity of tuning has been verified, which makes its energy harvesting efficiency relatively higher. The device model proposed in this paper would have potential application value in the field of vibration energy harvesting and wireless micro sensors power supply.

A bi-stable device for simultaneous vibration absorption and energy harvesting using bi-stable piezoelectric composite laminate

A bi-stable device is presented for simultaneous vibration absorption and energy harvesting by introducing the piezoelectric element into the bi-stable nonlinear energy sink (BNES), which is called the bi-stable piezoelectric absorber (BPZA). BPZA only consists of the cantilever bi-stable piezoelectric composite laminate (BPCL) and tip masses. This BPZA is a lightweight, simple and reliable structure since it does not need any external devices to maintain bistability. A finite element model (FEM) and an equivalent theoretical model are developed to model a harmonically excited linear oscillator coupled with BPZA. The Runge-Kutta method is used to solve the theoretical model numerically. The effects of the excitation amplitude, the tip mass of BPZA and the load resistance are considered on the vibration suppression efficiency and energy harvesting of BPZA. The results show adjusting these parameters can improve the vibration suppression efficiency and energy harvesting of BPZA. In addition, the experimental prototype is prepared and verifies the rightness of the finite element model and theoretical model. The BPZA achieves the goal of higher power density at lower acceleration and simultaneously has a good vibration absorption effect. Maximum power of 15.8mW is generated at an excitation frequency of 22 Hz and acceleration of 0.5 g.

A compact quasi-zero-stiffness device for vibration suppression and energy harvesting

In this study, a novel compact energy harvesting dynamic vibration absorber (EHDVA) with quasi-zero-stiffness (QZS) characteristics is engineered for both vibration suppression and energy harvesting under low frequency. The QZS EHDVA is composed of a negative stiffness magnetic spring (NSMS), a spiral flexure spring (SFS) and coils. Firstly, the analytical expressions of the force and stiffness of the NSMS are derived by using the equivalent magnetic charge method, and the restoring force of the SFS is analyzed with finite element method. The electromechanically coupled equations are then solved using the Harmonic Balance Method (HBM), and the effect of system parameters on both the performances of vibration suppression and energy harvesting is investigated in detail. Finally, the prototype of the QZS EHDVA is fabricated, and an experiment is carried out to verify the theoretical model. According to the testing findings, the QZS EHDVA is able to suppress vibration in the low frequency region between 3.7 Hz and 6.1 Hz. In addition, the maximum output power of 1.51 mW is achieved under a load resistance of 300Ω at a driving frequency of 4.5 Hz.

The Cutting Edge of Vibration Energy Harvesting Technology

Energy harvesting has been around for more than a decade, with continual research tackling the issues of charging and powering up electronic gadgets. Because of its multiple advantages, such as greater mobility and a longer lifespan, the notion of energy harvesting has acquired broad popularity. Researchers are investigating methods to harness the energy created by vibrations from various materials and transducers as part of the energy conservation movement. This paper examines major advancements in vibration energy collecting during the last 15 years. It focuses on the many processes used to collect vibration energy, such as piezoelectric, electromagnetic, electrostatic generators, and MEMs techniques, as well as power management circuits, to enhance various elements of vibration energy harvesting devices from diverse sources. While the research on vibration energy harvesting has grown significantly, this work summarises significant achievements in the subject over the last 15 years and updates prior review publications.

Analytical modeling of a device for vibration isolation and energy harvesting using simply-supported bi-stable hybrid symmetric laminate

The bi-stable hybrid symmetric laminate (BHSL) has been investigated for vibration isolation and energy harvesting, by taking advantage of its bi-stable characteristic. A device using simply-supported BHSL is proposed to integrate these two functions. This device is called the quasi-zero-stiffness (QZS) vibration isolator with a piezoelectric element (PE). An equivalent theoretical model is developed based on the restoring force-displacement curve of BHSL. The approximate analytical solutions and direct numerical solutions are obtained by the harmonic balance method and the Runge-Kutta method, respectively. Displacement transmissibility is utilized to quantify the vibration isolation performance of this vibration isolator. The influences of the excitation amplitude, the length of BHSL, the width of BHSL and the load resistance are analyzed. The results show that adjusting these parameters can improve the vibration isolation performance and energy harvesting performance. The QZS vibration isolator with PE achieves the goal of higher power density under a low-frequency and low-amplitude excitation and simultaneously has a good vibration isolation performance.

Analysis of electret-based vibration energy harvesting devices with curved-beam hinges

Recently, vibration energy harvesting devices have gained growing interests. One of the main requirements for them is a broad bandwidth owing to stochastic spectral characteristics of the general vibration sources. Among various approaches for wide bandwidth, curved-beam hinges are quite attractive due to their simple structures. Although there have been several reports on curved beams, a more detailed study is needed. The device under study is an electret-based one with balanced comb-drive configuration. The whole system is modeled by using nonlinear stochastic differential equations. The numerical analysis results show that there is an optimum curve height for maximum power output, which depends on various conditions, such as external vibration strength, comb-drive dimensions, and initial electret charges. At the external acceleration magnitude of 0.02 g and 0.05 g, the device with curved beams can produce up to 2.9 times and 4.8 times higher power output, respectively, than one with straight beams for given device geometries. To the contrary, at lower and higher vibration magnitudes, straight-beam devices harvest more energy than curved-beam ones. Therefore, it can be concluded that the curved beam height needs to be carefully determined based on the conditions of the application, especially on the characteristics of the external vibration sources.

Non-stationary response of nonlinear systems with singular parameter matrices subject to combined deterministic and stochastic excitation

A new technique is proposed for determining the response of multi-degree-of-freedom nonlinear systems with singular parameter matrices subject to combined deterministic and non-stationary stochastic excitation. Singular matrices in the governing equations of motion potentially account for the presence of constraints equations in the system. Further, they also appear when a redundant coordinates modeling is adopted to derive the equations of motion of complex multi-body systems. In this regard, the system response is decomposed into a deterministic and a stochastic component corresponding to the two components of the excitation. Then, two sets of differential equations are formulated and solved simultaneously to compute the system response. The first set pertains to the deterministic response component, whereas the second one pertains to the stochastic component of the response. The latter is derived by utilizing the generalized statistical linearization method for systems with singular matrices, while a formula for determining the time-dependent equivalent elements of the generalized statistical linearization methodology is also derived. The efficiency of the proposed technique is demonstrated by pertinent numerical examples. Specifically, a vibration energy harvesting device subject to combined deterministic and modulated white noise excitation and a structural nonlinear system with singular parameter matrices subject to combined deterministic and modulated white and colored noise excitations are considered.

Optimal Design of a Novel Piezoelectric Vibration Energy Harvester

A novel piezoelectric vibration energy harvester structure is designed. The output voltage is employed as the objective function, and the structural parameters of the vibration energy harvester device are optimized by Taguchi method. The best parameter combination of A3(95mm), B3(45mm), C1(60mm), D2(35mm) and E1(50mm) is determined. Through the analysis of variance, it is concluded that parameter A has the most obvious effect on the response of the piezoelectric energy harvester, with the contribution rate reaching 26.02%, and the influences of B, C, D and E decrease successively. The finite element model of the piezoelectric vibration energy harvester is established, then the load impedance matching characteristics and acceleration dependence of voltage are discussed.

REWoD-based vibrational energy harvesting exploiting saline-solutions loaded PAAm hydrogels on micro-structured aluminium oxides electrodes

Nowadays, sensors are among the most exploited systems in everyday life, with widespread applications stimulating increasing research. Usually, they require external power, thus adding issues such as periodic maintenance and size constraints. Energy harvesting (EH) from mechanical vibrations (VEH) can overcome such limitations: in particular, Reverse Electrowetting on Dielectric (REWoD) can provide a high-power density of ∼µW/cm2 by exploiting the mechanical modulation of the capacitance at the liquid/dielectric interface without additional external bias. Compared with other vibrational EH (VEH) techniques, REWoD harvests energy efficiently even from very low-frequency vibrations (<10 Hz,the range of human motion), and it is one of the most promising technologies for miniaturisation. Here we present a feasibility study and proof of concept for a portable VEH device, exploiting low-cost materials such as highly hydrophobic micro-structured Al oxide electrodes combined with off-the-shelf polyacrylamide (PAAm) hydrogels loaded with saline solutions. The PAAm hydrogels, thanks to heat treatment in LiCl solution, exhibit a negligible degradation compared to the typical hydrogel drying time. A laboratory prototype using 3 hydrogel hemispheres simultaneously generated an average power of ∼1.55 μW at 7 Hz with a power density of 9.1 nW/μl.

Compliant quasi-zero stiffness device for vibration energy harvesting and isolation

Using a small piezoelectric device to extract energy from low frequency (< 5 Hz) and ultra-low level (< 0.05 g) vibration environments is a very challenging task. The device with quasi-zero stiffness (QZS), widely used in vibration isolation, could be a good candidate for a low frequency energy harvester. However, the conventional QZS devices with complex frames are not very suitable for small-scale harvesters operating in low vibration conditions. To solve these problems, we propose a compact W-shaped compliant mechanism with the direct QZS. Both static and dynamic models have been established to investigate the performance. A compact prototype is fabricated for testing. The experimental results are in good agreement with numerical predictions and demonstrate a good energy harvesting performance under the excitation level below 0.02 g. The normalized power density can even reach 2.3 mW/cm 3 g 2 under the excitation level of 0.007 g at 3.5 Hz. This device can also serve as a compact low-frequency vibration isolator with the transmissibility of − 20 dB at 10 Hz. Overall, this compact QZS device shows a great potential to scalable applications of low-frequency energy harvesting and vibration isolation. Schematic diagram of the energy harvester. • A compact, W-shape compliant system is proposed with a quasi-zero stiffness. • The energy harvester can be used in low frequency environments ( < 5 Hz), and ultra-low vibration (< 0.02 g). • The device with a small size also shows a good performance in the isolation of vibrations at low frequencies.