Liquid encapsulated electrostatic energy harvester for low-frequency vibrations

2012 ◽  
Vol 24 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Ling Bu ◽  
Xiaoming Wu ◽  
Xiaohong Wang ◽  
Litian Liu
Keyword(s):  
Polyvinylidene Fluoride ◽  
Output Voltage ◽  
Energy Harvester ◽  
Low Frequency ◽  
Electrostatic Energy ◽  
Maximum Output ◽  
Flowing Liquid ◽  
Horizontal Vibration ◽  
Low Viscosity ◽  
High Relative Permittivity

This article presents the modeling, fabrication, and testing of liquid encapsulated energy harvester using polyvinylidene fluoride electrets. Unlike harvesters reported in previous literature, this liquid encapsulated energy harvester uses flowing liquid rather than conventional resonating structures to induce variable capacitance and is more suitable for low-frequency applications. Prototypes injected with three types of liquid ( N-methyl-2-pyrrolidone, N, N-dimethylformamide, and glycerin) are tested in horizontal vibration and rotary motion mode, respectively. The results show that N, N-dimethylformamide–injected prototypes display the most desirable performance in horizontal vibration testing at 1–10 Hz due to high relative permittivity and low viscosity, with maximum output voltage of 2.32 V and power of 0.18 µW at 10 Hz. Glycerin-injected prototypes perform best at 0.1–1 Hz rotation due to effective movement and highest permittivity, with maximum output voltage of 11.46 V and power of 2.19 µW at 1 Hz.

Broadband Rotational Energy Harvesting Using Micro Energy Harvester

2018 ◽  
Author(s):  
Jui-Ta Chien ◽  
Yung-Hsing Fu ◽  
Chao-Ting Chen ◽  
Shun-Chiu Lin ◽  
Yi-Chung Shu ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Output Voltage ◽  
Energy Harvester ◽  
Low Frequency ◽  
Rotational Energy ◽  
Open Circuit ◽  
Maximum Output ◽  
Rotational Excitation ◽  
Rotating Speed ◽  
Piezoelectric Energy

This paper proposes a broadband rotational energy harvesting setup by using micro piezoelectric energy harvester (PEH). When driven in different rotating speed, the PEH can output relatively high power which exhibits the phenomenon of frequency up-conversion transforming the low frequency of rotation into the high frequency of resonant vibration. It aims to power self-powered devices used in the applications, like smart tires, smart bearings, and health monitoring sensors on rotational machines. Through the excitation of the rotary magnetic repulsion, the cantilever beam presents periodically damped oscillation. Under the rotational excitation, the maximum output voltage and power of PEH with optimal impedance is 28.2 Vpp and 663 μW, respectively. The output performance of the same energy harvester driven in ordinary vibrational based excitation is compared with rotational oscillation under open circuit condition. The maximum output voltage under 2.5g acceleration level of vibration is 27.54 Vpp while the peak output voltage of 36.5 Vpp in rotational excitation (in 265 rpm).

scholarly journals Analytical Modeling of a Doubly Clamped Flexible Piezoelectric Energy Harvester with Axial Excitation and Its Experimental Characterization

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3861
Author(s):  
Jie Mei ◽  
Qiong Fan ◽  
Lijie Li ◽  
Dingfang Chen ◽  
Lin Xu ◽  
...  
Keyword(s):  
Output Power ◽  
Power Output ◽  
Output Voltage ◽  
Energy Harvester ◽  
Load Resistance ◽  
Engineering Practice ◽  
Maximum Output ◽  
Widespread Application ◽  
Piezoelectric Energy ◽  
Axial Excitation

With the rapid development of wearable electronics, novel power solutions are required to adapt to flexible surfaces for widespread applications, thus flexible energy harvesters have been extensively studied for their flexibility and stretchability. However, poor power output and insufficient sensitivity to environmental changes limit its widespread application in engineering practice. A doubly clamped flexible piezoelectric energy harvester (FPEH) with axial excitation is therefore proposed for higher power output in a low-frequency vibration environment. Combining the Euler–Bernoulli beam theory and the D’Alembert principle, the differential dynamic equation of the doubly clamped energy harvester is derived, in which the excitation mode of axial load with pre-deformation is considered. A numerical solution of voltage amplitude and average power is obtained using the Rayleigh–Ritz method. Output power of 22.5 μW at 27.1 Hz, with the optimal load resistance being 1 MΩ, is determined by the frequency sweeping analysis. In order to power electronic devices, the converted alternating electric energy should be rectified into direct current energy. By connecting to the MDA2500 standard rectified electric bridge, a rectified DC output voltage across the 1 MΩ load resistor is characterized to be 2.39 V. For further validation of the mechanical-electrical dynamical model of the doubly clamped flexible piezoelectric energy harvester, its output performances, including both its frequency response and resistance load matching performances, are experimentally characterized. From the experimental results, the maximum output power is 1.38 μW, with a load resistance of 5.7 MΩ at 27 Hz, and the rectified DC output voltage reaches 1.84 V, which shows coincidence with simulation results and is proved to be sufficient for powering LED electronics.

scholarly journals Study of the Properties of a Hybrid Piezoelectric and Electromagnetic Energy Harvester for a Civil Engineering Low-Frequency Sloshing Environment

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 391
Author(s):  
Nan Wu ◽  
Yuncheng He ◽  
Jiyang Fu ◽  
Peng Liao
Keyword(s):  
Output Power ◽  
Energy Harvester ◽  
Civil Engineering ◽  
Maximum Output Power ◽  
Low Frequency ◽  
Electromagnetic Energy ◽  
Maximum Output ◽  
Piezoelectric Film ◽  
Hybrid Energy ◽  
Level Height

In this paper a novel hybrid piezoelectric and electromagnetic energy harvester for civil engineering low-frequency sloshing environment is reported. The architecture, fabrication and characterization of the harvester are discussed. The hybrid energy harvester is composed of a permanent magnet, copper coil, and PVDF(polyvinylidene difluoride) piezoelectric film, and the upper U-tube device containing a cylindrical fluid barrier is connected to the foundation support plate by a hinge and spring. The two primary means of energy collection were through the vortex street, which alternately impacted the PVDF piezoelectric film through fluid shedding, and the electromotive force (EMF) induced by changes in the magnetic field position in the conducting coil. Experimentally, the maximum output power of the piezoelectric transformer of the hybrid energy harvester was 2.47 μW (circuit load 270 kΩ; liquid level height 80 mm); and the maximum output power of the electromagnetic generator was 2.72 μW (circuit load 470 kΩ; liquid level height 60 mm). The low-frequency sloshing energy collected by this energy harvester can drive microsensors for civil engineering monitoring.

scholarly journals FINITE ELEMENT SIMULATION OF MEMS PIEZOELECTRIC ENERGY SCAVENGER BASED ON PZT THIN FILM

2019 ◽  
Vol 20 (1) ◽  
pp. 90-99
Author(s):  
Aliza Aini Md Ralib ◽  
Nur Wafa Asyiqin Zulfakher ◽  
Rosminazuin Ab Rahim ◽  
Nor Farahidah Za'bah ◽  
Noor Hazrin Hany Mohamad Hanif
Keyword(s):  
Thin Film ◽  
Energy Harvesting ◽  
Output Voltage ◽  
Energy Harvester ◽  
Maximum Output Power ◽  
Vibration Energy ◽  
Maximum Output ◽  
Vibration Energy Harvesting ◽  
Piezoelectric Energy ◽  
The World

Vibration energy harvesting has been progressively developed in the advancement of technology and widely used by a lot of researchers around the world. There is a very high demand for energy scavenging around the world due to it being cheaper in price, possibly miniaturized within a system, long lasting, and environmentally friendly. The conventional battery is hazardous to the environment and has a shorter operating lifespan. Therefore, ambient vibration energy serves as an alternative that can replace the battery because it can be integrated and compatible to micro-electromechanical systems. This paper presents the design and analysis of a MEMS piezoelectric energy harvester, which is a vibration energy harvesting type. The energy harvester was formed using Lead Zicronate Titanate (PZT-5A) as the piezoelectric thin film, silicon as the substrate layer and structural steel as the electrode layer. The resonance frequency will provide the maximum output power, maximum output voltage and maximum displacement of vibration. The operating mode also plays an important role to generate larger output voltage with less displacement of cantilever. Some designs also have been studied by varying height and length of piezoelectric materials. Hence, this project will demonstrate the simulation of a MEMS piezoelectric device for a low power electronic performance. Simulation results show PZT-5A piezoelectric energy with a length of 31 mm and height of 0.16 mm generates maximum output voltage of 7.435 V and maximum output power of 2.30 mW at the resonance frequency of 40 Hz. ABSTRAK: Penuaian tenaga getaran telah berkembang secara pesat dalam kemajuan teknologi dan telah digunakan secara meluas oleh ramai penyelidik di seluruh dunia. Terdapat permintaan yang sangat tinggi di seluruh dunia terhadap penuaian tenaga kerana harganya yang lebih murah, bersaiz kecil dalam satu sistem, tahan lama dan mesra alam. Manakala, bateri konvensional adalah berbahaya bagi alam sekitar dan mempunyai jangka hayat yang lebih pendek. Oleh itu, getaran tenaga dari persekitaran lebih sesuai sebagai alternatif kepada bateri kerana ia mudah diintegrasikan dan serasi dengan sistem mikroelektromekanikal. Kertas kerja ini  membentangkan reka bentuk dan analisis tenaga piezoelektrik MEMS iaitu salah satu jenis penuaian tenaga getaran. Penuai tenaga ini dibentuk menggunakan Lead Zicronate Titanate (PZT-5A) sebagai lapisan filem tipis piezoelektrik, silikon sebagai lapisan substrat dan keluli struktur sebagai lapisan elektrod. Frekuensi resonans akan memberikan hasil tenaga maksima, voltan tenaga maksima dan getaran jarak maksima. Mod pengendalian juga memainkan peranan penting bagi menghasilkan tenaga yang lebih besar. Reka bentuk yang mempunyai ketinggian dan panjang berlainan juga telah diuji dengan menggunakan bahan piezoelektrik yang sama. Oleh itu, projek ini akan menghasilkan simulasi piezoelektrik MEMS yang sesuai digunakan bagi alat elektronik berkuasa rendah. Hasil simulasi menunjukkan dengan panjang 31 mm dan ketinggian 0.16 mm, piezoelektrik PZT ini menghasilkan voltan maksima sebanyak 7.435 V dan tenaga output maksima 2.30 mW pada frekuensi resonans 40 Hz.

scholarly journals Multimodal Hybrid Piezoelectric-Electromagnetic Insole Energy Harvester Using PVDF Generators

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 635 ◽  
Author(s):  
Muhammad Iqbal ◽  
Malik Muhammad Nauman ◽  
Farid Ullah Khan ◽  
Pg Emeroylariffion Abas ◽  
Quentin Cheok ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Degrees Of Freedom ◽  
Energy Harvester ◽  
Wearable Sensors ◽  
Hand Movement ◽  
Low Frequency ◽  
Open Circuit ◽  
Wearable Electronics ◽  
Mobile Source ◽  
Step Motion

Harvesting biomechanical energy is a viable solution to sustainably powering wearable electronics for continuous health monitoring, remote sensing, and motion tracking. A hybrid insole energy harvester (HIEH), capable of harvesting energy from low-frequency walking step motion, to supply power to wearable sensors, has been reported in this paper. The multimodal and multi-degrees-of-freedom low frequency walking energy harvester has a lightweight of 33.2 g and occupies a small volume of 44.1 cm3. Experimentally, the HIEH exhibits six resonant frequencies, corresponding to the resonances of the intermediate square spiral planar spring at 9.7, 41 Hz, 50 Hz, and 55 Hz, the Polyvinylidene fluoride (PVDF) beam-I at 16.5 Hz and PVDF beam-II at 25 Hz. The upper and lower electromagnetic (EM) generators are capable of delivering peak powers of 58 µW and 51 µW under 0.6 g, by EM induction at 9.7 Hz, across optimum load resistances of 13.5 Ω and 16.5 Ω, respectively. Moreover, PVDF-I and PVDF-II generate root mean square (RMS) voltages of 3.34 V and 3.83 V across 9 MΩ load resistance, under 0.6 g base acceleration. As compared to individual harvesting units, the hybrid harvester performed much better, generated about 7 V open-circuit voltage and charged a 100 µF capacitor up to 2.9 V using a hand movement for about eight minutes, which is 30% more voltage than the standalone piezoelectric unit in the same amount of time. The designed HIEH can be a potential mobile source to sustainably power wearable electronics and wireless body sensors.

Design and Numerical Analysis of an Electrostatic Energy Harvester With Impact for Frequency Up-Conversion

2020 ◽  
Vol 15 (5) ◽  
Author(s):  
R. Lensvelt ◽  
R. H. B. Fey ◽  
R. M. C. Mestrom ◽  
H. Nijmeijer
Keyword(s):  
Power Generation ◽  
High Frequency ◽  
Energy Harvester ◽  
Low Frequency ◽  
Electrostatic Energy ◽  
Computational Time ◽  
Ambient Vibrations ◽  
Frequency Oscillator ◽  
Low Frequency Power ◽  
Frequency Power

Abstract Integration of vibration energy harvesters (VEHs) with small-scale electronic devices may form an attractive alternative for relatively large batteries and can, potentially, increase their lifespan. However, the inherent mismatch between a harvester's high-frequency resonance, typically in the range 100−1000 Hz, relative to the available low-frequency ambient vibrations, typically in the range 10–100 Hz, means that low-frequency power generation in microscale VEHs remains a persistent challenge. In this work, we model a novel electret-based, electrostatic energy harvester (EEH) design. In this design, we combine an out-of-plane gap-closing comb (OPGC) configuration for the low-frequency oscillator with an in-plane overlap comb configuration for the high-frequency oscillator and employ impact for frequency up-conversion. An important design feature is the tunability of the resonance frequency through the electrostatic nonlinearity of the low-frequency oscillator. Impulsive normal forces due to impact are included in numerical simulation of the EEH through Moreau's time-stepping scheme which has, to the best of our knowledge, not been used before in VEH design and analysis. The original scheme is extended with time-step adjustments around impact events to reduce computational time. Using frequency sweeps, we numerically investigate power generation under harmonic, ambient vibrations. Results show improved low-frequency power generation in this EEH compared to a reference EEH. The EEH design shows peak power generation improvement of up to a relative factor 3.2 at low frequencies due to the occurrence of superharmonic resonances.

scholarly journals Wearable Core-Shell Piezoelectric Nanofiber Yarns for Body Movement Energy Harvesting

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 555 ◽  
Author(s):  
Sang Hyun Ji ◽  
Yong-Soo Cho ◽  
Ji Sun Yun
Keyword(s):  
Polyvinylidene Fluoride ◽  
Output Voltage ◽  
Energy Harvester ◽  
Body Movement ◽  
Effective Area ◽  
Core Shell ◽  
Body Movements ◽  
Bending Tests ◽  
The Core ◽  
Piezoelectric Energy

In an effort to fabricate a wearable piezoelectric energy harvester based on core-shell piezoelectric yarns with external electrodes, flexible piezoelectric nanofibers of BNT-ST (0.78Bi0.5Na0.5TiO3-0.22SrTiO3) and polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) were initially electrospun. Subsequently, core-shell piezoelectric nanofiber yarns were prepared by twining the yarns around a conductive thread. To create the outer electrode layers, the core-shell piezoelectric nanofiber yarns were braided with conductive thread. Core-shell piezoelectric nanofiber yarns with external electrodes were then directly stitched onto the fabric. In bending tests, the output voltages were investigated according to the total length, effective area, and stitching interval of the piezoelectric yarns. Stitching patterns of the piezoelectric yarns on the fabric were optimized based on these results. The output voltages of the stitched piezoelectric yarns on the fabric were improved with an increase in the pressure, and the output voltage characteristics were investigated according to various body movements of bending and pressing conditions.

Investigation on a broadband magnetic levitation energy harvester for railway scenarios

2021 ◽  
pp. 1045389X2110263
Author(s):  
Shoutai Li ◽  
Yifeng Wang ◽  
Mingjin Yang ◽  
Yuhua Sun ◽  
Fei Wu ◽  
...  
Keyword(s):  
Power Generation ◽  
Output Voltage ◽  
Energy Harvester ◽  
Magnetic Levitation ◽  
Maximum Output ◽  
Control Factors ◽  
Generation Capacity ◽  
Vibration Tests ◽  
Full Factorial ◽  
The Magnetic Field

In this study, a Magnetic Levitation Energy Harvester (MLEH) was designed and fabricated. The magnetic field distribution and power generation performance of multiple cylindrical magnets were studied. The full factorial design (FFD) of L20 (22 × 5) test was carried out with the sliding magnet arrangement, coil arrangement and wiring method as the control factors, and the output power as target factor. Sweeping-frequency vibration tests and railroad spectrum random vibration tests were conducted to verify the power generation capacity of the prototype. Experimental results show that the device has a broadband response and the railroad vibration test proves the effectiveness of harvester in the application scenario for powering the rail-side sensors. The range of maximum output voltage, power and corresponding frequency in sweeping-frequency vibration tests with the amplitude of 1 to 10 mm and frequency of 5 to 50 Hz are 1.5 to 4.5 V; 1.80 to 17.0 mW and 9.7 to 30.8 Hz. The maximum output voltage and power are 1.33 V and 1.47 mW based on the measured railroad spectrum. Finally, a retrospective review in the efficiency, effectiveness and volume figure of merit is conducted to evaluate the performance of MLEH, indicating a high power density of the proposed harvester.

scholarly journals Ocean energy harvester based on piezoelectric VIV using different oscillators

2019 ◽  
Vol 136 ◽  
pp. 02017
Author(s):  
Min Liu ◽  
Hui Xia ◽  
Guoqiang Liu ◽  
Dong Xia
Keyword(s):  
Output Voltage ◽  
Energy Harvester ◽  
Fluid Velocity ◽  
Electrical Energy ◽  
Coupling Model ◽  
Maximum Output ◽  
Ocean Energy ◽  
Velocity Change ◽  
Piezoelectric Energy ◽  
Piezoelectric Beam

A finite element fluid-solid coupling model for ocean energy harvester based on piezoelectric vortex-induced vibration(VIV) is established. Given that the Karman Vortex Street is generated after the fluid passes through the vibrator. The model includes the conversion of water flow energy to VIV energy and the capture of electrical energy by piezoelectric devices. And the output voltage curve is obtained by coupling with piezoelectric beam. Based on the fluid-solid coupling calculation, the dynamic response characteristics of the oscillator under different parameters such as shape of oscillators and fluid velocity are studied. The voltage output of piezoelectric beam in cylindrical, semi-cylindrical and regular triangular oscillators is analyzed. Simulation results show that the output voltage and pressure difference are largest in regular triangular oscillator system compared with the cylindrical and semi-cylindrical system. When changing fluid velocity, it is found that the higher the velocity of the water fluid be, the higher the output voltage be. When the given fluid velocity reaches 1 m/s, the maximum output voltage of cylindrical, semi-cylindrical and regular triangular piezoelectric energy harvesters reaches 0.045V, 0.08V, and 0.085V respectively. Under the same fluid velocity, change the ratio of height and width of oscillator, and find that the higher ratio of height and width of oscillator is more suitable to harvest the energy of VIV.

Novel Low-Frequency Rectangular-Loop Piezoelectric Energy Harvester

2014 ◽  
Vol 635-637 ◽  
pp. 928-931
Author(s):  
Shuai Yuan ◽  
Bing Jiang ◽  
Li Juan Chen ◽  
Yu Guo Hao ◽  
Jian Bo Xin ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Output Voltage ◽  
Energy Harvester ◽  
Low Frequency ◽  
Effective Bandwidth ◽  
Response Analysis ◽  
Element Analysis ◽  
Piezoelectric Energy ◽  
The Finite Element Analysis ◽  
Harmonic Response Analysis

The ambient energy harvesting based on piezoelectric has become an important subject in recent research publications. A new rectangular-loop piezoelectric energy harvester(RLPEH) is proposed. The characteristic is analyzed by the finite element analysis (FEA) which includes the static analysis, modal analysis and harmonic response analysis. The analysis results show that the RLPEH could reduce the resonant frequency and improve the output voltage. The three order resonant frequency is 18.6Hz, 40.8Hz and 85.4Hz. The output voltage is 42V under 3m/s2 of acceleration and the effective bandwidth is 18.7Hz with output voltage above 10V.

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