Enhanced Design of Vibration Energy Harvester Using Dual Masses

Author(s):  
Xiudong Tang ◽  
Lei Zuo

A type of dual-mass vibration energy harvester, where two masses are connected in series with the energy transducer and spring, is proposed and analyzed in this paper. The dual-mass vibration energy harvester is proved to be able to harvest more energy than the traditional single degree-of-freedom (DOF) one when subjected to harmonic force or base displacement excitation. The optimal parameters for maximizing the power output in both the traditional and the new configurations are discussed with taking the parasitic mechanical damping of the system into account. In consistent of the previous literature, we find that the optimal condition for maximum power output of the single DOF vibration energy harvester is when the excitation frequency equals to the natural frequency of the mechanical system and the electrical damping due to the energy harvesting circuit is the same as the mechanical damping. However, the optimal conditions are quite different for the dual-mass vibration energy harvester. It is found that two local optimums exist, where the optimal excitation frequency and electrical damping are analytically obtained. The local maximum power of the dual-mass vibration energy harvester is larger than the global maximum power of single DOF one. Moreover, at certain frequency range between the two natural frequencies of the dual-mass system, the harvesting power always increases with the electrical damping ratio. This suggests that we can obtain higher energy harvesting rate using dual-mass harvester. The sensitivity of the power to parameters, such as mass ratio and tuning ratio, is also investigated.

2018 ◽  
Vol 202 ◽  
pp. 02002
Author(s):  
Faruq Muhammad Foong ◽  
Chung Ket Thein ◽  
Beng Lee Ooi

Vibration energy harvesting has emerged as a promising source of sustainable energy to power small electronics. This study investigates the effect of total damping on the power output of an electromagnetic vibration energy harvester. Analytical results show that an increase in the effective mass of the harvester increases the mechanical damping but decreases the electromagnetic damping. The total damping of the harvester displayed an increasing trend with the effective mass when the electromagnetic damping is lower that the mechanical damping but changed into a decreasing trend when the electromagnetic damping becomes larger than the mechanical damping. Findings also suggest that there is an optimum proof mass to beam mass ratio where the harvester would produce maximum power in both cases of where a constant and varying optimum load resistance were considered.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Masoud Derakhshani ◽  
Thomas A. Berfield

Vibration-based energy harvesting via microelectromechanical system- (MEMS-) scale devices presents numerous challenges due to difficulties in maximizing power output at low driving frequencies. This work investigates the performance of a uniquely designed microscale bistable vibration energy harvester featuring a central buckled beam coated with a piezoelectric layer. In this design, the central beam is pinned at its midpoint by using a torsional rod, which in turn is connected to two cantilever arms designed to induce bistable motion of the central buckled beam. The ability to induce switching between stable states is a critical strategy for boosting power output of MEMS. This study presents the formulation of a model to analyze the static and dynamic behaviors of the coupled structure, with a focus on the evolution of elongation strain within the piezoelectric layer. Cases of various initial buckling stress levels, driving frequencies, and driving amplitude were considered to identify regimes of viable energy harvesting. Results showed that bistable-state switching, or snap-through motion of the buckled beam, produced a significant increase in power production potential over a range of driving frequencies. These results indicate that optimal vibration scavenging requires an approach that balances the initial buckling stress level with the expected range of driving frequencies for a particular environment.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 201-210
Author(s):  
Yoshikazu Tanaka ◽  
Satoru Odake ◽  
Jun Miyake ◽  
Hidemi Mutsuda ◽  
Atanas A. Popov ◽  
...  

Energy harvesting methods that use functional materials have attracted interest because they can take advantage of an abundant but underutilized energy source. Most vibration energy harvester designs operate most effectively around their resonant frequency. However, in practice, the frequency band for ambient vibrational energy is typically broad. The development of technologies for broadband energy harvesting is therefore desirable. The authors previously proposed an energy harvester, called a flexible piezoelectric device (FPED), that consists of a piezoelectric film (polyvinylidene difluoride) and a soft material, such as silicon rubber or polyethylene terephthalate. The authors also proposed a system based on FPEDs for broadband energy harvesting. The system consisted of cantilevered FPEDs, with each FPED connected via a spring. Simply supported FPEDs also have potential for broadband energy harvesting, and here, a theoretical evaluation method is proposed for such a system. Experiments are conducted to validate the derived model.


2014 ◽  
Vol 953-954 ◽  
pp. 655-658 ◽  
Author(s):  
Guang Qing Shang ◽  
Hong Bing Wang ◽  
Chun Hua Sun

Energy harvesting system has become one of important areas of ​​research and develops rapidly. How to improve the performance of the piezoelectric vibration energy harvester is a key issue in engineering applications. There are many literature on piezoelectric energy harvesting. The paper places focus on summarizing these literature of mathematical modeling of piezoelectric energy harvesting, ranging from the linear to nonlinear, from early a single mechanical degree to piezoaeroelastic problems.


2020 ◽  
Vol 142 (10) ◽  
Author(s):  
Shan Gao ◽  
Hongrui Ao ◽  
Hongyuan Jiang

Abstract Piezoelectric vibration energy harvesting technology has attracted significant attention for its applications in integrated circuits, microelectronic devices, and wireless sensors due to high power density, easy integration, simple configuration, and other outstanding features. Among piezoelectric vibration energy harvesting structures, the cantilevered beam is one of the simplest and most commonly used structures. In this work, a vertically staggered rectangle-through-holes (VS-RTH) cantilevered model is proposed, which focuses on the multi-directional vibration collection. To verify the output performance of the device, this paper employs basic materials and fabrication methods with mathematical modeling. The simulations are conducted through finite element methods to discuss the properties of VS-RTH energy harvester on resonant frequency and output characteristics. Besides, an energy storage circuit is adopted as a collection system. It can achieve a maximum voltage of 4.5 V which is responded to the harmonic vibrating input of 1 N force and 1 m/s2 in a single vibrating direction. Moreover, the power density is 2.596 W/cm3 with a 100 kΩ resistor. It is almost four times better than the output of unidirectional cantilever beam with similar resonant frequency and volume. According to the more functionality in the applications, VS-RTH energy harvester can be used in general vibration acquisition of machines and vehicles. Except for electricity storage, the harvester can potentially employ as a sensor to monitor the diversified physical signals for smooth operation and emergence reports. Looking forward, the VS-RTH harvester renders an effective approach toward decomposing the vibration directions in the environment for further complicating vibration applications.


2011 ◽  
Vol 403-408 ◽  
pp. 4231-4234 ◽  
Author(s):  
Khalid Ashraf ◽  
Mohd Haris Md Khir ◽  
John Ojur Dennis

This paper presents an impact-based frequency increased electromagnetic vibration energy harvester to scavenge energy in a low frequency environment. To realize the novel impact based frequency up-conversion mechanism, a coil has been elastically anchored with a platform on which four permanent magnets are arranged in such a way that a strong closed magnetic flux path, linking the coil, is formed. The proposed scavenger has two dynamics of motion. The first phase is a low frequency oscillation to absorb energy from ambient vibration during which both the coil and magnet act as proof mass and move collectively. The increased proof mass ensures maximization of absorbed energy. After crossing a certain clearance, the platform containing magnetic setup rigidly and supporting the coil elastically, collides with a rigid stopper and bounces back. As a result of this mechanical impact a high frequency oscillation is setup in the coil relative to the magnets during which energy is transferred to electrical domain by electromagnetic induction. A macro-prototype has been build to prove the proposed concept. Initial test results show that the proposed harvester generates a peak voltage of 1 volt across a load of 220 Ω at an excitation frequency of 5 Hz which corresponds to a peak power of 4.5 mW and average power of 660 µW.


Author(s):  
M. H. Ansari ◽  
M. Amin Karami

A piezoelectric vibration energy harvester is designed to generate electricity under the weight of passing crowds. The piezoelectric beam buckles to a controlled extent when the device is stepped on. The device is a seven bar mechanism. The upper and lower bars as well as the lateral links are rigid. The middle horizontal beam is a bimorph piezoelectric beam. Damages to the piezoelectric beam are avoided by constraining its axial deformation. This constrain is implemented by limiting squeezing of the mechanism. When a person moves over the mechanism or steps off the devices it causes the bimorph to buckle or return to the unbuckled condition. The transitions result in vibrations of the piezoelectric beam and thus generate energy. In this paper, the energy harvester is analytically modeled. The electro-mechanical coupling and the geometric nonlinearities have been included in the model for the piezoelectric beam. The design criteria for the device are discussed. It is demonstrated that the device can be realized with commonly used piezoelectric patches and can generate hundreds of milliwatts of power. A three part beam is also investigated. The effect of design parameters on the generated power and required tolerances are illustrated. The proposed device could be implemented in the sidewalks producing energy from the weight of people passing over it. Other possible applications are portable smart phones chargers and shoe hill energy harvesting. Dance floor of a club is another applicable example for using this harvester. The main advantage of using horizontal configuration instead of a vertical arrangement is the ease of placement in the pavements.


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