Electrical Energy Harvesting Using a Mechanical Rectification Approach

Aerospace ◽  
2006 ◽  
Author(s):  
R. M. Tieck ◽  
G. P. Carman ◽  
D. G. Enoch Lee

This paper presents a new approach using frequency rectification to harvest electrical energy from mechanical energy using piezoelectric devices. The rectification approach utilizes a linearly traveling Rectifier to impart vibrational motion to a cantilever piezoelectric bimorph. A conventional cantilever-type energy harvester is tested aside the rectified beam. The Standard beam generated 0.11 W of power, a power density of 15.63 kW/m3, and an energy density of 130.7 J/m3. The Rectified beam generated 580 mW of power, a power density of 871.92 kW/m3, and an energy density of 313.15 J/m3, a factor 2.4 greater than conventional energy harvesting methods. These results confirm the original thesis that a mechanically rectified piezoelectric Energy Harvester would generate larger Energy and Power Densities as well as Specific Powers, compared to conventional technologies.

Author(s):  
Shaofan Qi ◽  
Roger Shuttleworth ◽  
S. Olutunde Oyadiji

Energy harvesting is the process of converting low level ambient energy into usable electrical energy, so that remote electronic instruments can be powered without the need for batteries or other supplies. Piezoelectric material has the ability to convert mechanical energy into electrical energy, and cantilever type harvesters using this material are being intensely investigated. The typical single cantilever energy harvester design has a limited bandwidth, and is restricted in ability for converting environmental vibration occurring over a wide range of frequencies. A multiple cantilever piezoelectric generator that works over a range of frequencies, yet has only one Piezo element, is being investigated. The design and testing of this novel harvester is described.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2876
Author(s):  
Hailu Yang ◽  
Ya Wei ◽  
Weidong Zhang ◽  
Yibo Ai ◽  
Zhoujing Ye ◽  
...  

Road power generation technology is of significance for constructing smart roads. With a high electromechanical conversion rate and high bearing capacity, the stack piezoelectric transducer is one of the most used structures in road energy harvesting to convert mechanical energy into electrical energy. To further improve the energy generation efficiency of this type of piezoelectric energy harvester (PEH), this study theoretically and experimentally investigated the influences of connection mode, number of stack layers, ratio of height to cross-sectional area and number of units on the power generation performance. Two types of PEHs were designed and verified using a laboratory accelerated pavement testing system. The findings of this study can guide the structural optimization of PEHs to meet different purposes of sensing or energy harvesting.


Author(s):  
Tien-Kan Chung ◽  
Chieh-Min Wang ◽  
Chia-Yuan Tseng ◽  
Tzu-Wei Liu ◽  
Po-Chen Yeh

In this paper, we report a micro 3-D kinetic energy harvester demonstrating an energy conversion from environmental mechanical-energy (3-D mechanical motion) to electrical energy (voltage output). In addition to energy harvesting/conversion from 3-D motion, we demonstrate a non-contact frequency-up rectification approach which converts an incoming lower vibration frequency to a higher frequency in order to increase the power output of the harvester.


Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 803
Author(s):  
Zhongjie Li ◽  
Chuanfu Xin ◽  
Yan Peng ◽  
Min Wang ◽  
Jun Luo ◽  
...  

A novel hybridization scheme is proposed with electromagnetic transduction to improve the power density of piezoelectric energy harvester (PEH) in this paper. Based on the basic cantilever piezoelectric energy harvester (BC-PEH) composed of a mass block, a piezoelectric patch, and a cantilever beam, we replaced the mass block by a magnet array and added a coil array to form the hybrid energy harvester. To enhance the output power of the electromagnetic energy harvester (EMEH), we utilized an alternating magnet array. Then, to compare the power density of the hybrid harvester and BC-PEH, the experiments of output power were conducted. According to the experimental results, the power densities of the hybrid harvester and BC-PEH are, respectively, 3.53 mW/cm3 and 5.14 μW/cm3 under the conditions of 18.6 Hz and 0.3 g. Therefore, the power density of the hybrid harvester is 686 times as high as that of the BC-PEH, which verified the power density improvement of PEH via a hybridization scheme with EMEH. Additionally, the hybrid harvester exhibits better performance for charging capacitors, such as charging a 2.2 mF capacitor to 8 V within 17 s. It is of great significance to further develop self-powered devices.


2018 ◽  
Vol 29 (18) ◽  
pp. 3572-3581
Author(s):  
Suihan Liu ◽  
Ali Imani Azad ◽  
Rigoberto Burgueño

Piezoelectric energy harvesting from ambient vibrations is well studied, but harvesting from quasi-static responses is not yet fully explored. The lack of attention is because quasi-static actions are much slower than the resonance frequency of piezoelectric oscillators to achieve optimal outputs; however, they can be a common mechanical energy resource: from large civil structure deformations to biomechanical motions. The recent advances in bio-micro-electro-mechanical systems and wireless sensor technologies are motivating the study of piezoelectric energy harvesting from quasi-static conditions for low-power budget devices. This article presents a new approach of using quasi-static deformations to generate electrical power through an axially compressed bilaterally constrained strip with an attached piezoelectric layer. A theoretical model was developed to predict the strain distribution of the strip’s buckled configuration for calculating the electrical energy generation. Results from an experimental investigation and finite element simulations are in good agreement with the theoretical study. Test results from a prototyped device showed that a peak output power of 1.33 μW/cm2 was generated, which can adequately provide power supply for low-power budget devices. And a parametric study was also conducted to provide design guidance on selecting the dimensions of a device based on the external embedding structure.


Author(s):  
Prateek Asthana ◽  
Gargi Khanna

Piezoelectric energy harvesting refers to conversion of mechanical energy into usable electrical energy. In the modern connected world, wireless sensor nodes are scattered around the environment. These nodes are powered by batteries. Batteries require regular replacement, hence energy harvesters providing continuous autonomous power are used to power these sensor nodes. This work provides two different fixation modes for the resonant frequency for the two modes. Variation in geometric parameter and their effect on resonant frequency and output power have been analyzed. These harvesters capture a wide-band of ambient vibrations and convert them into usable electrical energy. To capture random ambient vibrations, the harvester used is a wide-band energy harvester based on conventional seesaw mechanism. The proposed structure operates on first two resonant frequencies in comparison to the conventional cantilever system working on first resonant frequency. Resonance frequency, as well as response to a varying input vibration frequency, is carried out, showing better performance of seesaw cantilever design. In this work, modeling of wide-band energy harvester with proof mass is being performed. Position of proof mass plays a key role in determining the resonant frequency of the harvester. Placing the proof mass near or away from fixed end results in increase and decrease in stress on the piezoelectric layer. Hence, to avoid the breaking of cantilever, the position of proof mass has been analyzed.


Author(s):  
H. Li ◽  
S. D. Hu ◽  
H. S. Tzou

Piezoelectric energy harvesting has experienced significant growth over the past few years. Various harvesting structures have been proposed to convert ambient vibration energies to electrical energy. However, these harvester’s base structures are mostly beams and some plates. Shells have great potential to harvest more energy. This study aims to evaluate a piezoelectric coupled conical shell based energy harvester system. Piezoelectric patches are laminated on the conical shell surface to convert vibration energy to electric energy. An open-circuit output voltage of the conical energy harvester is derived based on the thin-shell theory and the Donnel-Mushtari-Valsov theory. The open-circuit voltage and its derived energy consists of four components respectively resulting from the meridional and circular membrane strains, as well as the meridional and circular bending strains. Reducing the surface of the harvester to infinite small gives the spatial energy distribution on the shell surface. Then, the distributed modal energy harvesting characteristics of the proposed PVDF/conical shell harvester are evaluated in case studies. The results show that, for each mode with unit modal amplitude, the distribution depends on the mode shape, harvester location, and geometric parameters. The regions with high strain outputs yield higher modal energies. Accordingly, optimal locations for the PVDF harvester can be defined. Also, when modal amplitudes are specified, the overall energy of the conical shell harvester can be calculated.


2011 ◽  
Vol 22 (18) ◽  
pp. 2215-2228 ◽  
Author(s):  
Jayant Sirohi ◽  
Rohan Mahadik

There has been increasing interest in wireless sensor networks for a variety of outdoor applications including structural health monitoring and environmental monitoring. Replacement of batteries that power the nodes in these networks is maintenance intensive. A wind energy–harvesting device is proposed as an alternate power source for these wireless sensor nodes. The device is based on the galloping of a bar with triangular cross section attached to a cantilever beam. Piezoelectric sheets bonded to the beam convert the mechanical energy into electrical energy. A prototype device of size approximately 160 × 250 mm was fabricated and tested over a range of operating conditions in a wind tunnel, and the power dissipated across a load resistance was measured. A maximum power output of 53 mW was measured at a wind velocity of 11.6 mph. An analytical model incorporating the coupled electromechanical behavior of the piezoelectric sheets and quasi-steady aerodynamics was developed. The model showed good correlation with measurements, and it was concluded that a refined aerodynamic model may need to include apparent mass effects for more accurate predictions. The galloping piezoelectric energy-harvesting device has been shown to be a viable option for powering wireless sensor nodes in outdoor applications.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Long Zhang ◽  
Keith A. Williams ◽  
Zhengchao Xie

The power source with the limited life span has motivated the development of the energy harvesters that can scavenge the ambient environment energy and convert it into the electrical energy. With the coupled field characteristics of structure to electricity, piezoelectric energy harvesters are under consideration as a means of converting the mechanical energy to the electrical energy, with the goal of realizing completely self-powered sensor systems. In this paper, two previous models in the literatures for predicting the open-circuit and close-circuit voltages of a piezoelectric cantilever bimorph (PCB) energy harvester are first described, that is, the mechanical equivalent spring mass-damper model and the electrical equivalent circuit model. Then, the development of an enhanced coupled field model for the PCB energy harvester based on another previous model in the literature using a conservation of energy method is presented. Further, the laboratory experiments are carried out to evaluate the enhanced coupled field model and the other two previous models in the literatures. The comparison results show that the enhanced coupled field model can better predict the open-circuit and close-circuit voltages of the PCB energy harvester with a proof mass bonded at the free end of the structure in order to increase the energy-harvesting level of the system.


Author(s):  
Yuejuan Li ◽  
Marvin H. Cheng ◽  
Ezzat G. Bakhoum

Piezoelectric devices have been widely used as a means of transforming ambient vibrations into electrical energy that can be stored and used to power other devices. This type of power generation devices can provide a convenient alternative to traditional power sources used to operate certain types of sensors/actuators, MEMS devices, and microprocessor units. However, the amount of energy produced by these devices is in many cases far too small to directly power an electrical device. Therefore, much of the research into power harvesting has focused on methods of accumulating the energy until a sufficient amount is present, allowing the intended electronics to be powered. Due to the tiny amount of harvestable power from a single device, it is critical to collect vibration energy efficiently. Many research groups have developed various methods to operate the harvesting devices at their resonant frequencies for maximal amount of energy. Different techniques of conversion circuits are also investigated for efficient transformation from mechanical vibration to electrical energy. However, efforts have not been made to the analysis of array configuration of energy harvesting elements. Poor combination of piezoelectric elements, such as phase difference, cannot guarantee the increasing amount of harvested energy. To realize a piezoelectric energy-harvesting device with higher volume energy density, the energy conversion efficiencies of different array configurations were investigated. In the present study, various combinations of piezoelectric elements were analyzed to achieve higher volume energy density. A charging circuit for solid-state batteries with planned energy harvesting strategy was also proposed. With the planned harvesting strategy, the required charging time can be estimated. Thus, the applicable applications can be clearly identified. In this paper, optimal combination of piezoelectric cantilevers and different modes of charging methods were investigated. The results provide a means of choosing the piezoelectric device to be used and estimate the amount of time required to recharge a specific capacity solid-state battery.


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