Energy Harvesting From Hydraulic Pressure Fluctuations

2012 ◽  
Author(s):  
Kenneth A. Cunefare ◽  
Nalin Verma ◽  
Alper Erturk ◽  
Ellen Skow ◽  
Jeremy Savor ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Energy Harvester ◽  
Dynamic Pressure ◽  
High Energy ◽  
Sensor Nodes ◽  
Hydraulic Systems ◽  
Mean Pressure ◽  
Pressure Ripple ◽  
The Mean

State-of-the-art hydraulic hose and piping systems employ integral sensor nodes for structural health monitoring in order to avoid catastrophic failures. These systems lend themselves to energy harvesting for powering sensor nodes. The foremost reason is that the power intensity of hydraulic systems is orders of magnitude higher than typical energy harvesting sources considered to date, such as wind turbulence, water flow, or vibrations of civil structures. Hydraulic systems inherently have a high energy intensity associated with the mean pressure and flow. Accompanying the mean pressure is what is termed dynamic pressure ripple caused by the action of pumps and actuators. Pressure ripple is conducive to energy harvesting as it is a deterministic source with an almost periodic time domain behavior. Pressure ripple generally increases in magnitude with the mean pressure of the system, which in turn increases the power that can be harvested. The harvested energy in hydraulic systems could enable self-powered wireless sensor nodes for applications such as energy-autonomous structural health monitoring and prognosis. An energy harvester prototype was designed for generating low-power electricity from dynamic pressure ripples. The prototype employed an axially-poled off-the-shelf piezoelectric stack. A housing isolated the stack from the hydraulic fluid while maintaining mechanical coupling to the system to allow for dynamic pressure induced deflection of the stack. The system exhibits an attractive off-resonance energy harvesting problem since the fundamental resonance of the piezoelectric stack is much higher than the frequency content of ripple. Although the energy harvester is not excited at resonance, the high energy intensity of the ripple results in significant electrical power output. The prototype provided a maximum output of 1.2 mW at 120Ω. With these results, it is clear that the energy harvester provides non-negligible power output suitable for powering sensors and other low power components. This work also presents electromechanical model simulations for predicting the piezoelectric power output in terms of the force transmitted from the pressure ripple as well as experimental characterization of the power output as a function of the force from the ripple.

Power Density Performance Improvements for High Pressure Ripple Energy Harvesting

2013 ◽  
Author(s):  
Nalin Verma ◽  
Kenneth A. Cunefare ◽  
Ellen Skow ◽  
Alper Erturk
Keyword(s):  
High Pressure ◽  
Root Mean Square ◽  
Power Output ◽  
Energy Harvester ◽  
Dynamic Pressure ◽  
Hydraulic Pressure ◽  
Pressure Amplitude ◽  
Mean Square ◽  
Pressure Ripple ◽  
Ripple Amplitude

A hydraulic pressure energy harvester (HPEH) device, which utilizes a housing to isolate a piezoelectric stack from the hydraulic fluid via a mechanical interface, generates power by converting the dynamic pressure within the system into electricity. Prior work developed an HPEH device capable of generating 2187 microWatts from an 85 kPa pressure ripple amplitude using a 1387 mm3 stack. A new generation of HPEH produced 157 microWatts at the test conditions of 18 MPa static pressure and 394 kPa root-mean-square pressure amplitude using a 50 mm3 stack, thus increasing the power produced per volume of piezoelectric stack principally due to the higher dynamic pressure input. The stack and housing design implemented on this new prototype device yield a compact, high-pressure hydraulic pressure energy harvester designed to withstand 35 MPa. The device, which is less than a 2.54 cm in length as compared to a 5.3 cm length of a previous HPEH, was statically tested up to 21.9 MPa and dynamically tested up to 19 MPa with 400 kPa root-mean-square dynamic pressure amplitude. An inductor was included in the load circuit in parallel with the stack and the load resistance to increase the power output of the device. A previously developed electromechanical power output model for this device that predicts the power output given the dynamic pressure ripple amplitude is compared to the power results. The power extracted from this device would be sufficient to meet the proposed applications of the device, which is to power sensor nodes in hydraulic systems.

Optimization of energy harvesting based on the uniform deformation of piezoelectric ceramic

2016 ◽  
Vol 09 (05) ◽  
pp. 1650069 ◽  
Author(s):  
Yaoze Liu ◽  
Tongqing Yang ◽  
Fangming Shu
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Piezoelectric Ceramic ◽  
Energy Harvester ◽  
Optimization Method ◽  
Piezoelectric Energy ◽  
Bonding Area ◽  
Almost All ◽  
Matching Load ◽  
Tip Mass

Since the piezoelectric properties were used for energy harvesting, almost all forms of energy harvester needs to be bonded with a mass block to achieve pre-stress. In this article, disc type piezoelectric energy harvester is chosen as the research object and the relationship between mass bonding area and power output is studied. It is found that if the bonding area is changed as curved, which is usually complanate in previous studies, the deformation of the circular piezoelectric ceramic is more uniform and the power output is enhanced. In order to test the change of the deformation, we spray several homocentric annular electrodes on the surface of a piece of bare piezoelectric ceramic and the output of each electrode is tested. Through this optimization method, the power output is enhanced to more than 11[Formula: see text]mW for a matching load about 24[Formula: see text]k[Formula: see text] and a tip mass of 30[Formula: see text]g at its resonant frequency of 139[Formula: see text]Hz.

A Belleville-Spring Based Piezoelectric or Electromagnetic Energy Harvester

2014 ◽  
Author(s):  
Davide Castagnetti
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Experimental Validation ◽  
Energy Harvester ◽  
Elastic System ◽  
Low Frequency ◽  
Electromagnetic Energy ◽  
Frequency Range ◽  
Modal Response ◽  
Force Displacement

Energy harvesting from kinetic ambient energy requires converters able to efficiently operate in the low frequency range. A limit of the solutions proposed in the literature, both electromagnetic and piezoelectric, is their operating frequency, which generally ranges from about 50 to 300 Hz. To overcome these limitations, this work proposes an innovative energy harvester exploiting two counteracting Belleville springs. Thanks to the peculiar height to thickness ratio of the springs a highly compliant elastic system is obtained, which can be used either for electromagnetic or piezoelectric harvesting. The harvester is modelled analytically and numerically both with regard to the force-displacement and to the modal response. The experimental validation of the harvester, highlights a noticeable power output but at a higher eigenfrequency than expected.

Performance Analysis of Piezoelectric Energy Harvesting in Pavement: Laboratory Testing and Field Simulation

2019 ◽  
Vol 2673 (3) ◽  
pp. 115-124 ◽  
Author(s):  
Abbas F. Jasim ◽  
Hao Wang ◽  
Greg Yesner ◽  
Ahmad Safari ◽  
Pat Szary
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Laboratory Testing ◽  
Energy Harvester ◽  
Total Power ◽  
Piezoelectric Energy Harvesting ◽  
Loading Frequency ◽  
Vehicle Speed ◽  
Piezoelectric Energy ◽  
Energy Harvesting System

This study investigated the energy harvesting performance of a piezoelectric module in asphalt pavements through laboratory testing and multi-physics based simulation. The energy harvester module was assembled with layers of Bridge transducers and tested in the laboratory. A decoupled approach was used to study the interaction between the energy harvester and the surrounding pavement. The effects of embedment location, vehicle speed, and temperature on energy harvesting performance were investigated. The analysis findings indicate that the embedment location and vehicle speed affects the resulted power output of the piezoelectric energy harvesting system. The embedment depth of the energy module affects both the magnitude and frequency of stress pulse on top of the energy module induced by tire loading. On the other hand, higher vehicle speed causes greater loading frequency and thus greater power output; the effect of pavement temperature is negligible. The analysis of total power output before reaching fatigue failure of the energy module can be used to determine the optimum embedment location in the asphalt layer. The proposed energy harvesting system provides great potential to generate green energy from waste kinetic energy in roadway pavements. Field study is recommended to verify these findings with long-term performance monitoring of pavement with embedded energy harvesters.

Design and Modeling of Hydraulic Pressure Energy Harvesters for Low Dynamic Pressure Environments

2014 ◽  
Author(s):  
Ellen Skow ◽  
Kenneth Cunefare ◽  
Alper Erturk
Keyword(s):  
High Pressure ◽  
Piezoelectric Material ◽  
Load Transfer ◽  
Dynamic Pressure ◽  
Distribution Networks ◽  
Sensor Nodes ◽  
Hydraulic Pressure ◽  
Cross Sectional ◽  
Energy Harvesters ◽  
Pressure Ripple

Hydraulic Pressure Energy Harvesters (HPEHs) use the direct piezoelectric effect to extract electrical power from the dynamic pressure ripple present in hydraulic systems. As with other energy harvesters, an HPEH is intended to be an enabling technology for powering sensor nodes. To date, HPEH devices have been developed for high-pressure, high-dynamic pressure ripple systems. High-pressure applications are common in industrial hydraulics, where static pressures may be up to 35 MPa. Other fluid systems, such as cross-country pipelines as well as water distribution networks operate at much lower pressures, e.g., from around 1 to 4 MPa, with proportionally lower dynamic pressures. Single-crystal piezoelectric materials are incorporated into the HPEH design, along with means to increase the load transfer into the piezoelectric material as well as increased output harvester circuits, so as to increase the power output of these devices. The load transfer from the pressurized fluid into the piezoelectric material is through an interface, where the interface area may be designed such that the area exposed to the fluid is greater than the cross-sectional area of the piezoelectric, yielding higher stress in the material than the pressure in the fluid. Furthermore, given the relatively large capacitance of the piezoelectric elements used in HPEH devices, inductive-tuned resonant harvester circuits implemented with passive elements are feasible. HPEH devices integrating these features are shown to produce viable power outputs from low dynamic pressure systems.

Flexoelectric Energy Harvesting Using Circular Thin Membranes

2020 ◽  
Vol 87 (9) ◽  
Author(s):  
Zhaoqi Li ◽  
Qian Deng ◽  
Shengping Shen
Keyword(s):  
Energy Harvesting ◽  
Energy Harvester ◽  
Energy Conversion Efficiency ◽  
High Energy ◽  
Circular Membrane ◽  
Governing Equations ◽  
Energy Harvesters ◽  
Thin Membranes ◽  
High Energy Conversion Efficiency ◽  
Working Frequency

Abstract In this work, we propose a circular membrane-based flexoelectric energy harvester. Different from previously reported nanobeams based flexoelectric energy harvesters, for the flexoelectric membrane, the polarization direction around its center is opposite in sign to that far away from the center. To avoid the cancelation of the electric output, electrodes coated to upper and lower surfaces of the flexoelectric membrane are respectively divided into two parts according to the sign of bending curvatures. Based on Hamilton’s principle and Ohm’s law, we obtain governing equations for the circular membrane-based flexoelectric energy harvester. A generalized assumed-modes method is employed for solving the system, so that the performance of the flexoelectric energy harvester can be studied in detail. We analyze the effects of the thickness h, radius r0, and their ratio on the energy harvesting performance. Specifically, we show that, by selecting appropriate h and r0, it is possible to design an energy harvester with both high energy conversion efficiency and low working frequency. At last, through numerical simulations, we further study the optimization ratio for which the electrodes should be divided.

Theoretical and experimental studies of a piezoelectric ring energy harvester

2019 ◽  
Vol 30 (7) ◽  
pp. 998-1009 ◽  
Author(s):  
XF Zhang ◽  
HS Tzou
Keyword(s):  
Energy Harvesting ◽  
Power Output ◽  
Output Voltage ◽  
Laboratory Experiments ◽  
Electromechanical Coupling ◽  
Energy Harvester ◽  
Experimental Studies ◽  
Design Parameters ◽  
Resistive Load ◽  
Practical Applications

Based on the electromechanical coupling of piezoelectricity, a piezoelectric ring energy harvester is designed and tested in this study, such that the harvester can be used to power electric devices in the closed-circuit condition. Output energies across the external resistive load are evaluated when the ring energy harvester is subjected to harmonic excitations, and various design parameters are discussed to maximize the power output. In order to validate the theoretical energy harvesting results, laboratory experiments are conducted. Comparing experiment results with theoretical ones, the errors between them are under 10% for the output voltage. Laboratory experiments demonstrate that the ring energy harvester is workable in practical applications.

Investigations of a Stiffness Tunable Nonlinear Vibrational Energy Harvester

2014 ◽  
Vol 14 (08) ◽  
pp. 1440023 ◽  
Author(s):  
Dongxu Su ◽  
Kimihiko Nakano ◽  
Rencheng Zheng ◽  
Matthew P. Cartmell
Keyword(s):  
Energy Harvesting ◽  
Permanent Magnets ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Duffing Oscillator ◽  
Experimental Tests ◽  
High Energy ◽  
Practical Implementation ◽  
Energy Harvesting Devices ◽  
Energy Orbit

The recent potential benefit of nonlinearity has been applying in order to improve the effectiveness of energy harvesting devices. For instance, at relatively high excitation levels, both low and high-energy responses can coexist for the same parameter combinations in a hardening type Duffing oscillator, and this provides a wider bandwidth and a higher energy harvesting effectiveness under periodic excitations. However, frequency or amplitude sweeps of the excitation must be used in order to reach a desirable high-energy orbit, and this gives a limitation on practical implementation. This paper presents a stiffness tunable nonlinear vibrational energy harvester which contains a moving magnetic end mass attached to a cantilever beam, whose nonlinearity emerges from the interaction forces with two neighboring permanent magnets facing with opposing poles. The motivating hypothesis has been that the jump from the low-energy orbit to the high-energy orbit can be triggered by tuning the stiffness of the system without changing the frequency or the amplitude of the excitation. Theoretical investigations show a methodology for tuning stiffness, and experimental tests have validated that the proposed method can be used to trigger a jump to the desirable state, and hereby this can broaden the bandwidth of the energy harvester.

scholarly journals Stabilisation of the high-energy orbit for a non-linear energy harvester with variable damping

2015 ◽  
Vol 230 (12) ◽  
pp. 2003-2012 ◽  
Author(s):  
Dongxu Su ◽  
Rencheng Zheng ◽  
Kimihiko Nakano ◽  
Matthew P Cartmell
Keyword(s):  
Energy Harvesting ◽  
Energy Harvester ◽  
High Energy ◽  
Low Energy ◽  
Additional Energy ◽  
Non Linear ◽  
In Series ◽  
Improved Performance ◽  
Non Linear Oscillator ◽  
Energy Orbit

The non-linearity of a hardening-type oscillator provides a wider bandwidth and a higher energy harvesting capability under harmonic excitations. Also, both low- and high-energy responses can coexist for the same parameter combinations at relatively high excitation levels. However, if the oscillator’s response happens to coincide with the low-energy orbit then the improved performance achieved by the non-linear oscillator over that of its linear counterpart, could be impaired. This is therefore the main motivation for stabilisation of the high-energy orbit. In the present work, a schematic harvester design is considered consisting of a mass supported by two linear springs connected in series, each with a parallel damper, and a third-order non-linear spring. The equivalent linear stiffness and damping coefficients of the oscillator are derived through variation of the damper element. From this adjustment the variation of the equivalent stiffness generates a corresponding shift in the frequency–amplitude response curve, and this triggers a jump from the low-energy orbit to stabilise the high-energy orbit. This approach has been seen to require little additional energy supply for the adjustment and stabilisation, compared with that needed for direct stiffness tuning by mechanical means. Overall energy saving is of particular importance for energy harvesting applications. Subsequent results from simulation and experimentation confirm that the proposed method can be used to trigger a jump to the desirable state, thereby introducing a beneficial addition to the performance of the non-linear hardening-type energy harvester that improves overall efficiency and broadens the bandwidth.

A Bistable Piezoelectric Energy Harvester With an Elastic Magnifier for Applications in Medical Pacemakers

2016 ◽  
Author(s):  
Antonio C. Galbier ◽  
M. Amin Karami
Keyword(s):  
Energy Harvesting ◽  
Physical Model ◽  
Energy Harvester ◽  
Experimental Testing ◽  
Magnetic Interaction ◽  
High Energy ◽  
Heart Beat ◽  
Bistable System ◽  
Beam Structures ◽  
Piezoelectric Energy

Embedded piezoelectric energy harvesting (PEH) systems in medical pacemakers have been an attractive and well visited research area. These systems typically utilize different configurations of beam structures with forcing originating from heart beat oscillations. The goal of these systems is to remove the pacemaker battery, which makes up 60–80% of the device volume, and replace it with a self-reliant power option. With emerging technologies encouraging a push towards leadless pacemakers typical energy harvesting beam structures are becoming inherently coupled with the heart system. The introduction of the nonlinearity resulting from the bistable magnetic interaction of two magnets is known to enhance energy harvesting performance due to its double-well potential behavior. Introducing the elastic magnifier enables large tip oscillations and high energy orbits for the bistable system. A continuous nonlinear model is derived for the bistable system (BPEH) and a one-degree-of-freedom linear mass-spring-damper model is derived for the elastic magnifier. The elastic magnifier (EM) will not consider the damping negligible due to the viscous nature of the heart, unlike most models. For experimental testing a physical model was created for the bistable structure and fashioned to an elastic magnifier. A hydrogel was chosen as the physical model for the EM. Experimental results have shown that the bistable piezoelectric energy harvester coupled with a linear elastic magnifier (BPEH+LEM) produces more power at certain input frequencies and operates a larger bandwidth than a PEH, BPEH, and a standard piezoelectric energy harvester with the elastic magnifier (PEH+LEM). Numerical simulations were validated by these results showing that this system enters high-energy and high orbit oscillations. It has been shown that BPEH systems implemented in medical pacemakers can have enhanced performance if positioned over the myocardial heart wall.

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