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Last update: November 12, 2013.
1

Adaptive vibration energy harvesting  

Microsoft Academic Search

By scavenging energy from their local environment, portable electronic devices such as mobile phones, radios and wireless sensors can achieve greater run-times with potentially lower weight. Vibration energy harvesting is one such approach where energy from parasitic vibrations can be converted into electrical energy, through the use of piezoelectric and electromagnetic transducers. Parasitic vibrations come from a range of sources

Sam Behrens; John Ward; Josh Davidson

2007-01-01

2

Piezoelectric Vibration Energy Harvesting Device.  

National Technical Information Service (NTIS)

A piezoelectric vibration energy harvesting device which is made up of a first mass, a second, a first spring coupled to the first mass, and a second spring coupled to the second mass. A piezoelectric element is bonded between the first mass and the secon...

K. Andic K. K. Deng

2005-01-01

3

Increasing sensitivity of vibration energy harvester  

Microsoft Academic Search

This paper deals with an electromagnetic vibration energy harvester which generates electrical energy from ambient vibrations. This harvester provides an autonomous source of energy for wireless applications, with an expected power consumption of several mW, placed in an environment excited by ambient vibrations. A tuned up design of the harvester with an electromagnetic converter provides sufficient generating of electrical energy

Z. Hadas; C. Ondrusek; V. Singule

2009-01-01

4

Increasing sensitivity of vibration energy harvester  

NASA Astrophysics Data System (ADS)

This paper deals with an electromagnetic vibration energy harvester which generates electrical energy from ambient vibrations. This harvester provides an autonomous source of energy for wireless applications, with an expected power consumption of several mW, placed in an environment excited by ambient vibrations. A tuned up design of the harvester with an electromagnetic converter provides sufficient generating of electrical energy for wireless applications. The output power depends on a frequency and level of the vibration and sensitivity of the energy harvester. Our harvester includes a unique spring-less resonance mechanism where stiffness is provided by repelled magnetic forces. The sensitivity is affected only by friction forces inside the mechanism of the harvester. Ways of decreasing friction, it means an increasing sensitivity, are investigated in this paper. The increasing sensitivity of the harvester provides more generated energy or decrease of the harvester size and weight.

Hadas, Z.; Ondrusek, C.; Singule, V.

2009-05-01

5

Power sensitivity of vibration energy harvester  

Microsoft Academic Search

This paper deals with a power sensitivity improvement of an electromagnetic vibration energy harvester which generates electrical\\u000a energy from ambient vibrations. The harvester provides an autonomous source of energy for wireless applications, with an expected\\u000a power consumption of several mW, placed in environment excited by ambient mechanical vibrations. An appropriately tuned up\\u000a design of the harvester with adequate sensitivity provides

Zdenek Hadas; Cestmir Ondrusek; Vladislav Singule

2010-01-01

6

Adaptive learning algorithms for vibration energy harvesting  

Microsoft Academic Search

By scavenging energy from their local environment, portable electronic devices such as MEMS devices, mobile phones, radios and wireless sensors can achieve greater run times with potentially lower weight. Vibration energy harvesting is one such approach where energy from parasitic vibrations can be converted into electrical energy through the use of piezoelectric and electromagnetic transducers. Parasitic vibrations come from a

John K. Ward; Sam Behrens

2008-01-01

7

PERFORMANCE OF MICROFABRICATED PIEZOELECTRIC VIBRATION ENERGY HARVESTERS  

Microsoft Academic Search

Model verification and design of MEMS piezoelectric vibration energy harvesters (MPVEH) are presented, motivated by lowering power requirements of wireless sensor nodes. Applications include structural health monitoring. Coupled electromechanical harvester models are presented and verified (through comparison with experimental data). Harvester material selection is discussed. The model is used to concurrently design a prototype MPVEH and a microfabrication scheme. Targeting

NOËL DUTOIT; BRIAN WARDLE

2006-01-01

8

A vibration energy harvesting device with bidirectional resonance frequency tunability  

Microsoft Academic Search

Vibration energy harvesting is an attractive technique for potential powering of wireless sensors and low power devices. While the technique can be employed to harvest energy from vibrations and vibrating structures, a general requirement independent of the energy transfer mechanism is that the vibration energy harvesting device operate in resonance at the excitation frequency. Most energy harvesting devices developed to

Vinod R Challa; M G Prasad; Yong Shi; Frank T Fisher

2008-01-01

9

Vibration energy harvesting by magnetostrictive material  

Microsoft Academic Search

A new class of vibration energy harvester based on magnetostrictive material (MsM), Metglas 2605SC, is designed, developed and tested. It contains two submodules: an MsM harvesting device and an energy harvesting circuit. Compared to piezoelectric materials, the Metglas 2605SC offers advantages including higher energy conversion efficiency, longer life cycles, lack of depolarization and higher flexibility to survive in strong ambient

Lei Wang; F. G. Yuan

2008-01-01

10

On energy harvesting from ambient vibration  

Microsoft Academic Search

Future MEMS devices will harvest energy from their environment. One can envisage an autonomous condition monitoring vibration sensor being powered by that same vibration, and transmitting data over a wireless link; inaccessible or hostile environments are obvious areas of application. The base excitation of an elastically mounted magnetic seismic mass moving past a coil, considered previously by several authors, is

N. G. Stephen

2006-01-01

11

Energy harvesting vibration sources for microsystems applications  

Microsoft Academic Search

This paper reviews the state-of-the art in vibration energy harvesting for wireless, self-powered microsystems. Vibration-powered generators are typically, although not exclusively, inertial spring and mass systems. The characteristic equations for inertial-based generators are presented, along with the specific damping equations that relate to the three main transduction mechanisms employed to extract energy from the system. These transduction mechanisms are: piezoelectric,

S P Beeby; M J Tudor; N M White

2006-01-01

12

Vibration based energy harvesting using piezoelectric material  

Microsoft Academic Search

Energy harvesting has been around for centuries in the form of windmills, watermills and passive solar power systems. It is not only restricted to the natural resources but it has widen the tapping source to utilise the vibration which happen all around us. In the last decade, beam with piezoceramic patches have been used as a method to harverst energy.

M. N Fakhzan; Asan G. A. Muthalif

2011-01-01

13

Multiple cell configuration electromagnetic vibration energy harvester  

Microsoft Academic Search

This paper reports the design of an electromagnetic vibration energy harvester that doubles the magnitude of output power generated by the prior four-bar magnet configuration. This enhancement was achieved with minor increase in volume by 23% and mass by 30%. The new 'double cell' design utilizes an additional pair of magnets to create a secondary air gap, or cell, for

Anthony Marin; Scott Bressers; Shashank Priya

2011-01-01

14

A broadband vibration energy harvester using magnetoelectric transducer  

Microsoft Academic Search

In order for vibration energy harvesters to be efficiently applicable over a range of source frequencies, recently much research has been done to broaden the frequency range of the harvesters using piezoelectric, electromagnetic and electrostatic transductions, but little has been investigated in the harvesters using magnetoelectric transducers. In this paper, a new broadband vibration energy harvester using magneto electric transducer

Jin Yang; Yumei Wen; Ping Li; Xianzhi Dai; Ming Li

2010-01-01

15

Potential system efficiencies for MEMS vibration energy harvesting  

Microsoft Academic Search

Reliable power sources are needed for portable micro-electromechanical systems (MEMS) devices such as wireless automobile tire pressure sensors. Vibration is an ubiquitous energy source that maybe 'harvested' as electrical energy at the site of the MEMS device. Existing vibration energy harvesting systems use either a piezoelectric or an electromagnetic transducer to convert vibrations into electrical energy. This electrical energy is

S. Behrens

2007-01-01

16

Vibration energy harvesting for unmanned aerial vehicles  

NASA Astrophysics Data System (ADS)

Unmanned aerial vehicles (UAVs) are a critical component of many military operations. Over the last few decades, the evolution of UAVs has given rise to increasingly smaller aircraft. Along with the development of smaller UAVs, termed mini UAVs, has come issues involving the endurance of the aircraft. Endurance in mini UAVs is problematic because of the limited size of the fuel systems that can be incorporated into the aircraft. A large portion of the total mass of many electric powered mini UAVs, for example, is the rechargeable battery power source. Energy harvesting is an attractive technology for mini UAVs because it offers the potential to increase their endurance without adding significant mass or the need to increase the size of the fuel system. This paper investigates the possibility of harvesting vibration and solar energy in a mini UAV. Experimentation has been carried out on a remote controlled (RC) glider aircraft with a 1.8 m wing span. This aircraft was chosen to replicate the current electric mini UAVs used by the military today. The RC glider was modified to include two piezoelectric patches placed at the roots of the wings and a cantilevered piezoelectric beam installed in the fuselage to harvest energy from wing vibrations and rigid body motions of the aircraft, as well as two thin film photovoltaic panels attached to the top of the wings to harvest energy from sunlight. Flight testing has been performed and the power output of the piezoelectric and photovoltaic devices has been examined.

Anton, Steven R.; Inman, Daniel J.

2008-05-01

17

A wideband vibration-based energy harvester  

Microsoft Academic Search

We present a new architecture for wideband vibration-based micro-power generators (MPGs). It replaces a linear oscillator with a piecewise-linear oscillator as the energy harvesting element of the MPG. A prototype of an electromagnetic MPG designed accordingly is analyzed analytically, numerically and experimentally. We find that the new architecture increases the bandwidth of the MPG during a frequency up-sweep, while maintaining

M S M Soliman; E M Abdel-Rahman; E F El-Saadany; R R Mansour

2008-01-01

18

Electromagnetic vibration energy harvesting device optimization by synchronous energy extraction  

Microsoft Academic Search

This paper investigates a new application of nonlinear techniques for vibration energy harvesting. The Synchronous Electric Charge Extraction (SECE) energy harvesting technique for piezoelectric generators is extended and adapted to electromagnetic generators. This new circuit, which is the dual of the SECE circuit, is named SMFE for Synchronous Magnetic Flux Extraction. A theoretical model is developed, and the harvested power

E. Arroyo; A. Badel

2011-01-01

19

Multiple cell configuration electromagnetic vibration energy harvester  

NASA Astrophysics Data System (ADS)

This paper reports the design of an electromagnetic vibration energy harvester that doubles the magnitude of output power generated by the prior four-bar magnet configuration. This enhancement was achieved with minor increase in volume by 23% and mass by 30%. The new 'double cell' design utilizes an additional pair of magnets to create a secondary air gap, or cell, for a second coil to vibrate within. To further reduce the dimensions of the device, two coils were attached to one common cantilever beam. These unique features lead to improvements of 66% in output power per unit volume (power density) and 27% increase in output power per unit volume and mass (specific power density), from 0.1 to 0.17 mW cm-3 and 0.41 to 0.51 mW cm-3 kg-1 respectively. Using the ANSYS multiphysics analysis, it was determined that for the double cell harvester, adding one additional pair of magnets created a small magnetic gradient between air gaps of 0.001 T which is insignificant in terms of electromagnetic damping. An analytical model was developed to optimize the magnitude of transformation factor and magnetic field gradient within the gap.

Marin, Anthony; Bressers, Scott; Priya, Shashank

2011-07-01

20

On the Effectiveness of Vibration-based Energy Harvesting  

Microsoft Academic Search

There has been a significant increase in the research on vibration-based energy harvesting in recent years. Most research is focused on a particular technology, and it is often difficult to compare widely differing designs and approaches to vibration-based energy harvesting. The aim of this study is to provide a general theory that can be used to compare different approaches and

Shad Roundy

2005-01-01

21

Enhanced Vibrational Energy Harvesting Using Non-linear Stochastic Resonance  

Microsoft Academic Search

Stochastic resonance has seen wide application in the physical sciences as a tool to understand weak signal ampliflcation by noise. However, this apparently counter- intuitive phenomenon does not appear to have been exploited as a tool to enhance vibrational energy harvesting. In this note we demonstrate that by adding periodic forcing to a vibrationally excited energy harvesting mechanism, the power

C. R. McInnes; D. G. Gorman; M. P. Cartmell

2008-01-01

22

Harvesting vibration energy using nonlinear oscillations of an electromagnetic inductor  

Microsoft Academic Search

Harvesting energy from ambient vibration is a promising method for providing a continuous source of power for wireless sensor nodes. However, traditional energy harvesters are often derived from resonant linear oscillators which are capable of providing sufficient output power only if the dominant frequency of input vibrations closely matches the device resonant frequency. The limited scope of such devices has

Christopher Lee; David Stamp; Nitin R. Kapania; José Oscar Mur-Miranda

2010-01-01

23

Vibration energy harvesting from random force and motion excitations  

Microsoft Academic Search

A vibration energy harvester is typically composed of a spring–mass system with an electromagnetic or piezoelectric transducer connected in parallel with a spring. This configuration has been well studied and optimized for harmonic vibration sources. Recently, a dual-mass harvester, where two masses are connected in series by the energy transducer and a spring, has been proposed. The dual-mass vibration energy

Xiudong Tang; Lei Zuo

2012-01-01

24

A low-frequency vibration-to-electrical energy harvester  

Microsoft Academic Search

As the power consumption of modern electronics and wireless circuits decreases to a few hundred microwatts, it becomes possible to power these electronic devices by using ambient energy harvested from the environment. Mechanical vibration is among the more pervasive ambient available energy forms. Recent works in vibration-to-electrical energy harvesters have been centered on high frequency vibration applications. Although high-frequency mechanical

Min Zhang; Daniel Brignac; Pratul Ajmera; Kun Lian

2008-01-01

25

A vibration energy harvester using magnetostrictive\\/piezoelectric composite transducer  

Microsoft Academic Search

An energy harvester is presented to convert ambient mechanical vibration into electrical energy. The harvester consists of a cantilever beam, a magnetic circuit and a magnetostrictive\\/piezoelectric laminate magnetoelectric (ME) transducer. The magnetic circuit is arranged on the free end of the beam and produces a concentrated flux gradient. When the harvester is excited, the magnetic circuit moves relative to the

Xianzhi Dai; Yumei Wen; Ping Li; Jin Yang; Xiaofang Jiang

2009-01-01

26

On Mechanical Modeling of Cantilevered Piezoelectric Vibration Energy Harvesters  

Microsoft Academic Search

Cantilevered beams with piezoceramic (PZT) layers are the most commonly investigated type of vibration energy harvesters. A frequently used modeling approach is the single-degree-of-freedom (SDOF) modeling of the harvester beam as it allows simple expressions for the electrical outputs. In the literature, since the base excitation on the harvester beam is assumed to be harmonic, the well known SDOF relation

A. Erturk; D. J. Inman

2008-01-01

27

Vibration energy harvesting from random force and motion excitations  

NASA Astrophysics Data System (ADS)

A vibration energy harvester is typically composed of a spring-mass system with an electromagnetic or piezoelectric transducer connected in parallel with a spring. This configuration has been well studied and optimized for harmonic vibration sources. Recently, a dual-mass harvester, where two masses are connected in series by the energy transducer and a spring, has been proposed. The dual-mass vibration energy harvester is proved to be able to harvest more power and has a broader bandwidth than the single-mass configuration, when the parameters are optimized and the excitation is harmonic. In fact, some dual-mass vibration energy harvesters, such as regenerative vehicle suspensions and buildings with regenerative tuned mass dampers (TMDs), are subjected to random excitations. This paper is to investigate the dual-mass and single-mass vibration harvesters under random excitations using spectrum integration and the residue theorem. The output powers for these two types of vibration energy harvesters, when subjected to different random excitations, namely force, displacement, velocity and acceleration, are obtained analytically with closed-form expressions. It is also very interesting to find that the output power of the vibration energy harvesters under random excitations depends on only a few parameters in very simple and elegant forms. This paper also draws some important conclusions on regenerative vehicle suspensions and buildings with regenerative TMDs, which can be modeled as dual-mass vibration energy harvesters. It is found that, under white-noise random velocity excitation from road irregularity, the harvesting power from vehicle suspensions is proportional to the tire stiffness and road vertical excitation spectrum only. It is independent of the chassis mass, tire-wheel mass, suspension stiffness and damping coefficient. Under random wind force excitation, the power harvested from buildings with regenerative TMD will depends on the building mass only, not on the parameters of the TMD subsystem if the ratio of electrical and mechanical damping is constant.

Tang, Xiudong; Zuo, Lei

2012-07-01

28

A MEMS vibration energy harvester for automotive applications  

NASA Astrophysics Data System (ADS)

The objective of this work is to develop MEMS vibration energy harvesters for tire pressure monitoring systems (TPMS), they can be located on the rim or on the inner-liner of the car tire. Nowadays TPMS modules are powered by batteries with a limited lifetime. A large effort is ongoing to replace batteries with small and long lasting power sources like energy harvesters [1]. The operation principle of vibration harvesters is mechanical resonance of a seismic mass, where mechanical energy is converted into electrical energy. In general, vibration energy harvesters are of specific interest for machine environments where random noise or repetitive shock vibrations are present. In this work we present the results for MEMS based vibration energy harvesting for applying on the rim or inner-liner. The vibrations on the rim correspond to random noise. A vibration energy harvester can be described as an under damped mass-spring system acting like a mechanical band-pass filter, and will resonate at its natural frequency [2]. At 0.01 g2/Hz noise amplitude the average power can reach the level that is required to power a simple wireless sensor node, approximately 10 ?W [3]. The dominant vibrations on the inner-liner consist mainly of repetitive high amplitude shocks. With a shock, the seismic mass is displaced, after which the mass will "ring-down" at its natural resonance frequency. During the ring-down period, part of the mechanical energy is harvested. On the inner-liner of the tire repetitive (one per rotation) high amplitude (few hundred g) shocks occur. The harvester enables an average power of a few tens of ?W [4], sufficient to power a more sophisticated wireless sensor node that can measure additional tire-parameters besides pressure. In this work we characterized MEMS vibration energy harvesters for noise and shock excitation. We validated their potential for TPMS modules by measurements and simulation.

van Schaijk, R.; Elfrink, R.; Oudenhoven, J.; Pop, V.; Wang, Z.; Renaud, M.

2013-05-01

29

A variable-capacitance vibration-to-electric energy harvester  

Microsoft Academic Search

Past research on vibration energy harvesting has focused primarily on the use of magnets or piezoelectric materials as the basis of energy transduction, with few experimental studies implementing variable-capacitance-based scavenging. In contrast, this paper presents the design and demonstration of a variable-capacitance vibration energy harvester that combines an asynchronous diode-based charge pump with an inductive energy flyback circuit to deliver

Bernard C. Yen; Jeffrey H. Lang

2006-01-01

30

Characterization of Direct Piezoelectric Properties for Vibration Energy Harvesting  

NASA Astrophysics Data System (ADS)

Direct piezoelectric effect of Pb(Zr,Ti)O3 (PZT) thin films was investigated to discuss the application of ferroelectric films to vibration energy harvesting. From the model of the piezoelectric vibration energy harvester, it was found that the figure of merit (FOM) is proportional of the square of the effective transverse piezoelectric coefficient e31,f. The e31,f coefficient of PZT films were measured by substrate bending method. Furthermore, it was found that the e31,f coefficient increases with increasing strain, which is favourable for the vibration energy harvesting.

Yoshimura, Takeshi; Miyabuchi, Hiroki; Murakami, Syuichi; Ashida, Atsushi; Fujimura, Norifumi

2011-10-01

31

MEMS-based thick film PZT vibrational energy harvester  

Microsoft Academic Search

We present a MEMS-based unimorph silicon\\/PZT thick film vibrational energy harvester with an integrated proof mass. We have developed a process that allows fabrication of high performance silicon based energy harvesters with a yield higher than 90%. The process comprises a KOH etch using a mechanical front side protection of an SOI wafer with screen printed PZT thick film. The

A. Lei; R. Xu; A. Thyssen; A. C. Stoot; T. L. Christiansen; K. Hansen; R. Lou-Moller; E. V. Thomsen; K. Birkelund

2011-01-01

32

Evaluating vehicular-induced bridge vibrations for energy harvesting applications  

NASA Astrophysics Data System (ADS)

Highway bridges are vital links in the transportation network in the United States. Identifying possible safety problems in the approximately 600,000 bridges across the country is generally accomplished through labor-intensive, visual inspections. Ongoing research sponsored by NIST seeks to improve inspection practices by providing real-time, continuous monitoring technology for steel bridges. A wireless sensor network with a service life of ten years that is powered by an integrated energy harvester is targeted. In order to achieve the target ten-year life for the monitoring system, novel approaches to energy harvesting for use in recharging batteries are investigated. Three main sources of energy are evaluated: (a) vibrational energy, (b) solar energy, and (c) wind energy. Assessing the energy produced from vehicular-induced vibrations and converted through electromagnetic induction is the focus of this paper. The goal of the study is to process acceleration data and analyze the vibrational response of steel bridges to moving truck loads. Through spectral analysis and harvester modeling, the feasibility of vibration-based energy harvesting for longterm monitoring can be assessed. The effects of bridge conditions, ambient temperature, truck traffic patterns, and harvester position on the power content of the vibrations are investigated. With sensor nodes continually recharged, the proposed real-time monitoring system will operate off the power grid, thus reducing life cycle costs and enhancing inspection practices for state DOTs. This paper will present the results of estimating the vibration energy of a steel bridge in Texas.

Reichenbach, Matthew; Fasl, Jeremiah; Samaras, Vasilis A.; Wood, Sharon; Helwig, Todd; Lindenberg, Richard

2012-03-01

33

Harvesting vibration energy using nonlinear oscillations of an electromagnetic inductor  

NASA Astrophysics Data System (ADS)

Harvesting energy from ambient vibration is a promising method for providing a continuous source of power for wireless sensor nodes. However, traditional energy harvesters are often derived from resonant linear oscillators which are capable of providing sufficient output power only if the dominant frequency of input vibrations closely matches the device resonant frequency. The limited scope of such devices has sparked an interest in the use of nonlinear oscillators as mechanisms for broadband energy harvesting. In this study, we investigate the harvesting performance of an electromagnetic harvester sustaining oscillations through the phenomena of magnetic levitation. The nonlinear behavior of the device is effectively modeled by Duffing's equation, and direct numerical integration confirms the broadband frequency response of the nonlinear harvester. The nonlinear harvester's power generation capabilities are directly compared to a linear electromagnetic harvester with similar dynamic parameters. Experimental testing shows that the presence of both high and low amplitude solutions for the nonlinear energy harvester results in a tendency for the oscillator to remain in a low energy state for non-harmonic vibration inputs, unless continuous energy impulses are provided. We conclude by considering future applications and improvements for such nonlinear devices.

Lee, Christopher; Stamp, David; Kapania, Nitin R.; Mur-Miranda, José Oscar

2010-04-01

34

Capacitive vibration energy harvesting with resonance tuning  

Microsoft Academic Search

Electromechanical conversion of mechanical vibration into electrical energy looks very attractive for industrial applications recently proposed and involving wireless sensors networks. A preliminary analysis of the energy scavenger configuration is proposed by investigating the performance of microsystems based on the electrostatic coupling and testing the power scavenged by a capacitive microscavenger, with out-of-plane gap closing layout. This study includes some

G. De Pasquale; E. Brusa; A. Soma

2009-01-01

35

A multi-frequency sandwich type electromagnetic vibration energy harvester  

NASA Astrophysics Data System (ADS)

We proposed a multi-frequency sandwich type vibration energy harvester to widen the effective frequency range of vibration energy harvester. The harvester is composed of three resonant structures with different natural frequencies. The resonant structures are two cantilevers each with bi-layer coils and a plane spring with a magnet. The maximum peak-peak voltages of the three different frequencies are 172 mV, 104 mV, and 112 mV at the frequencies of 235 Hz, 330 Hz, and 430 Hz, respectively. The first maximum voltage is much higher than the others, because the coils in both cantilevers can produce voltages.

Chen, Jingdong; Chen, Di; Yuan, Tao; Chen, Xiang

2012-05-01

36

Power Processing Circuits for Piezoelectric Vibration-Based Energy Harvesters  

Microsoft Academic Search

The behavior of a piezoelectric vibration-driven energy harvester with different power processing circuits is evaluated. Two load types are considered: a resistive load and an ac-dc rectifier load. An optimal resistive and optimal dc-voltage load for the harvester is analytically calculated. The difference between the optimal output power flow from the harvester to both load circuits depends on the coupling

R. D'hulst; T. Sterken; R. Puers; G. Deconinck; J. Driesen

2010-01-01

37

A Multimode Relayed Piezoelectric Cantilever for Effective Vibration Energy Harvesting  

NASA Astrophysics Data System (ADS)

A piezoelectric cantilever with an eccentrically connected wire-mass relay is proposed for extensive energy harvesting from broadband vibration responses. The relay mass is chosen to be much greater than that of the cantilever. The vibration source is magnified by the relay as a bending-swinging-torsional excitation to drive the cantilever. Thus, multiple vibration modes of the cantilever are effectively employed to enhance energy harvesting. A prototype device was developed and characterized. The results show that the proposed structure can generate much more electricity over a broader bandwidth than conventional structures.

Li, Chuan; Hong, Daewoong; Kwon, Kwang-Ho; Jeong, Jaehwa

2013-05-01

38

Development of MEMS-based Piezoelectric Vibration Energy Harvesters  

Microsoft Academic Search

\\u000a In this paper, the development of a first generation MEMS-based piezoelectric energy harvester capable of converting ambient\\u000a vibrations into storable electrical energy is presented. The energy harvester is designed using a validated analytical electromechanical\\u000a Lumped Element Model (LEM) that accurately predicts the behavior of a piezoelectric composite structure. The MEMS device is\\u000a fabricated using standard sol gel PZT and conventional

39

Autonomous Low Power Microsystem Powered by Vibration Energy Harvesting  

Microsoft Academic Search

This paper reports, for the first time, the implementation of a microsystem powered entirely from ambient vibrations. Sufficient electrical energy is harvested to power a radio-frequency (RF) linked accelerometer based microsystem. The microsystem is energy aware and will adjust the measurement\\/transmit duty cycle according to the available energy; this is typically every 50 seconds during normal operation. The system is

R. N. Torah; M. J. Tudor; K. Patel; I. N. Garcia; S. P. Beeby

2007-01-01

40

A Vibration-Based PMN-PT Energy Harvester  

Microsoft Academic Search

We report design, modeling, analysis, and experimental study of a vibration-based piezoelectric energy harvester. The energy harvester is made of a composite cantilever of a single crystal relaxor ferroelectric material, (1- x)Pb(Mg1\\/3Nb2\\/3)O3-xPbTiO3 (PMN-PT), and a polydimethylsiloxane (PDMS) base layer. A PDMS proof mass is constructed at the tip of the composite cantilever beam and is used as a means to

Alex Mathers; Kee S. Moon; Jingang Yi

2009-01-01

41

Experimental study of a hybrid vibration energy harvesting mechanism  

Microsoft Academic Search

In this paper, a novel hybrid vibration energy harvesting mechanism integrating effects of both electromagnetic induction and piezoelectricity have been presented. The structure topologically consists of three modules. The first is electromagnetic induction module comprising of two pairs of bulk NdFeB permanent magnet and one hand-wound enameled copper coil. The second is piezoelectric energy harvesting module utilizing impact mode. The

Song-mao Chen; Jun-hui Hu

2011-01-01

42

Development of a Cantilever Beam Generator Employing Vibration Energy Harvesting  

Microsoft Academic Search

This paper details the development of a generator based upon a cantilever beam inertial mass system which harvests energy from ambient environmental vibrations. The paper compares the predicted results from Finite Element Analysis (FEA) of the mechanical behaviour and magnetic field simulations and experimental results from a generator. Several design changes were implemented to maximise the conversion of magnetic energy

R. N. Torah; S. P. Beeby; M. J. Tudor; T. O'Donnell; S. Roy

43

Electrostatic vibration energy harvester with piezoelectric start-up generator  

Microsoft Academic Search

The search for compact autonomous devices has been increasing in the microelectronics industry. These devices have the capacity to generate their own energy in order to be charged. One of the ways of harvesting environmental energy for charging such devices is by using mechanical vibrations through the use of variable capacitor. Taking this principle a basis, this work presents a

Helder R. Florentino; Raimundo C. S. Freire; Alan V. S. Sa; Caio Florentino; Dimitri Galayko

2011-01-01

44

Design and fabrication of a micro electromagnetic vibration energy harvester  

Microsoft Academic Search

This paper presents a new micro electromagnetic energy harvester that can convert transverse vibration energy to electrical power. It mainly consists of folded beams, a permanent magnet and copper planar coils. The calculated value of the natural frequency is 274 Hz and electromagnetic simulation shows that the magnetic flux density will decrease sharply with increasing space between the magnet and

Wang Peng; Li Wei; Che Lufeng

2011-01-01

45

Design, Modeling, and Performance Measurements of a Broadband Vibration Energy Harvester Using a Magnetoelectric Transducer  

Microsoft Academic Search

This article presents a new broadband vibration energy harvester using a magnetoelectric (ME) transducer. In order for vibration energy harvesters to be efficiently applicable over a range of vibration frequencies, many techniques have recently been investigated to broaden the frequency ranges of the harvesters using piezoelectric, electromagnetic, or electrostatic transductions, but few have been studied in the harvesters using ME

Jin Yang; Yumei Wen; Ping Li; Xianzhi Dai

2011-01-01

46

A micro electromagnetic generator for vibration energy harvesting  

Microsoft Academic Search

Vibration energy harvesting is receiving a considerable amount of interest as a means for powering wireless sensor nodes. This paper presents a small (component volume 0.1 cm3, practical volume 0.15 cm3) electromagnetic generator utilizing discrete components and optimized for a low ambient vibration level based upon real application data. The generator uses four magnets arranged on an etched cantilever with

S P Beeby; R N Torah; M J Tudor; P Glynne-Jones; T O'Donnell; C R Saha; S Roy

2007-01-01

47

Fundamental issues in nonlinear wideband-vibration energy harvesting.  

PubMed

Mechanically nonlinear energy harvesters driven by broadband vibrations modeled as white noise are investigated. We derive an upper bound on output power versus load resistance and show that, subject to mild restrictions that we make precise, the upper-bound performance can be obtained by a linear harvester with appropriate stiffness. Despite this, nonlinear harvesters can have implementation-related advantages. Based on the Kramers equation, we numerically obtain the output power at weak coupling for a selection of phenomenological elastic potentials and discuss their merits. PMID:23679394

Halvorsen, Einar

2013-04-29

48

Novel piezoelectric bistable oscillator architecture for wideband vibration energy harvesting  

NASA Astrophysics Data System (ADS)

Bistable vibration energy harvesters are attracting more and more interest because of their capability to scavenge energy over a large frequency band. The bistable effect is usually based on magnetic interaction or buckled beams. This paper presents a novel architecture based on amplified piezoelectric structures. This buckled spring-mass architecture allows the energy of the dynamic mass to be converted into electrical energy in the piezoelectric materials as efficiently as possible. Modeling and design are performed and a normalized expression of the harvester behavior is given. Chirp and band-limited noise excitations are used to evaluate the proposed harvester’s performances. Simulation and experimental results are in good agreement. A method of using a spectrum plot for investigating the interwell motion is presented. The effect of the electric load impedance matching strategy is also studied. Results and comparisons with the literature show that the proposed device combines a large bandwidth and a high power density.

Liu, W. Q.; Badel, A.; Formosa, F.; Wu, Y. P.; Agbossou, A.

2013-03-01

49

Optimisation of electromagnetic vibrational energy harvesting device  

Microsoft Academic Search

This paper describes a model for an electromagnetic based, vibrational power generator and investigates the optimum conditions for load resistance, displacement and voltage in order to extract maximum electrical power from mechanical vibrations. Two macro-generators have been built and tested in order to verify the model.

C. R. Saha; T. O'Donnell; H. Loder

2006-01-01

50

An Autoparametric, Electromagnetic Ambient Vibration Energy Harvester  

Microsoft Academic Search

Results are presented for the design and testing of an electromagnetic device to convert ambient mechanical vibration into electricity. The design of the device is based on an L-shaped beam structure which is tuned so that the first two (bending) natural frequencies have a (near) two-to-one ratio. This creates an internal resonance or autoparmetic condition that can result in a

Johannes Santen; Nitin R. Kapania; Christopher L. Lee

2011-01-01

51

Dielectric Electroactive Polymer energy harvesting system forward path design for different vibration input patterns  

Microsoft Academic Search

Energy harvesting is a new emerging technology which is used to gathering ambient energy from surroundings. In this paper, we propose a new application idea that to harvest ambient vibration energy and store it into a Li-ion rechargeable battery by using Dielectric Electroactive Polymer (DEAP) generator. For proposed energy harvesting prototyping system, according to two different vibration input patterns in

Wei Wang; Peiwen He; Setiawan Soekamtoputra; Feng Ge; Ken Choi; Gyungsoo Kang; SooHyun Kim

2011-01-01

52

Vibration energy harvesting for low power and wireless applications  

NASA Astrophysics Data System (ADS)

Vibration energy harvesting is an attractive technique for the potential powering of wireless sensors and low power devices. While the technique can be employed to harvest energy from ambient and mechanical vibrations, there are several generic requirements independent of the energy transfer mechanism that needs to be satisfied for efficient energy harvesting which are pursued here. For example, most energy harvesting devices developed are based on a single resonance frequency, and while recently efforts are being attempted to broaden the frequency range of the devices, lacking is a robust frequency tunable technique. In this work, a resonance frequency tunable mechanism employing magnetic force/stiffness technique is developed that allows the device frequency to increase or decrease based on the mode (attractive, repulsive) of the magnetic force applied. The developed technique provides the device to tune to approximately +/- 25% of its untuned resonance frequency allowing a wide frequency bandwidth. Further, this technique is developed into a self-tunable technique for autonomous device development. Another generic requirement is to match the electrical damping to the mechanical damping in the energy harvesting system for maximum efficiency. To satisfy this requirement, two independent energy harvesting techniques (piezoelectric and electromagnetic) are coupled through design, resulting in ˜30% and ˜65.5% increase in two different independent devices. Another key requirement is developing MEMS scale energy harvesting devices that will not only promises to enhance the power density but also allows potential integration with wireless sensors as an on-chip power source. Piezoelectric MEMS composite structures along with integrated silicon tip masses are fabricated using standard microfabrication techniques. Spray coating and spin coating techniques were explored to deposit zinc oxide as the piezoelectric material. Commercially available magnets were employed to demonstrate the frequency tuning/calibration of these structures resulting in ˜50% bandwidth. These approaches set the stage for a MEMS scale frequency tuning mechanism to be developed that would allow the integration of a self-tunability methodology for a completely autonomous MEMS scale energy harvesting devices for wide applications.

Challa, Vinod Reddy

53

Equivalent damping and frequency change for linear and nonlinear hybrid vibrational energy harvesting systems  

Microsoft Academic Search

A unified approximation method is derived to illustrate the effect of electro-mechanical coupling on vibration-based energy harvesting systems caused by variations in damping ratio and excitation frequency of the mechanical subsystem. Vibrational energy harvesters are electro-mechanical systems that generate power from the ambient oscillations. Typically vibration-based energy harvesters employ a mechanical subsystem tuned to resonate with ambient oscillations. The piezoelectric

M. Amin Karami; Daniel J. Inman

2011-01-01

54

Vibration energy harvesting using a piezoelectric circular diaphragm array.  

PubMed

This paper presents a method for harvesting electric energy from mechanical vibration using a mechanically excited piezoelectric circular membrane array. The piezoelectric circular diaphragm array consists of four plates with series and parallel connection, and the electrical characteristics of the array are examined under dynamic conditions. With an optimal load resistor of 160 k?, an output power of 28 mW was generated from the array in series connection at 150 Hz under a prestress of 0.8 N and a vibration acceleration of 9.8 m/s(2), whereas a maximal output power of 27 mW can be obtained from the array in parallel connection through a resistive load of 11 k? under the same frequency, prestress, and acceleration conditions. The results show that using a piezoelectric circular diaphragm array can significantly increase the output of energy compared with the use of a single plate. By choosing an appropriate connection pattern (series or parallel connections) among the plates, the equivalent impedance of the energy harvesting devices can be tailored to meet the matched load of different applications for maximal power output. PMID:23007776

Wang, Wei; Yang, Tongqing; Chen, Xurui; Yao, Xi

2012-09-01

55

Optimum power and efficiency of piezoelectric vibration energy harvesters with sinusoidal and random vibrations  

NASA Astrophysics Data System (ADS)

Assuming a sinusoidal vibration as input, an inertial piezoelectric harvester designed for maximum efficiency of the electromechanical energy conversion does not always lead to maximum power generation. In this case, what can be gained by optimizing the efficiency of the device? Detailing an answer to this question is the backbone of this paper. It is shown that, while the maximum efficiency operating condition does not always lead to maximum power generation, it corresponds always to maximum power per square unit deflection of the piezoelectric harvester. This understanding allows better optimization of the generated power when the deflection of the device is limited by hard stops. This is illustrated by experimental measurements on vacuum-packaged MEMS harvesters based on AlN as piezoelectric material. The results obtained for a sinusoidal vibration are extended to random vibrations. In this case, we demonstrate that the optimum generated power is directly proportional to the efficiency of the harvester, thus answering the initial question. For both types of studied vibrations, simple closed-form formulas describing the generated power and efficiency in optimum operating conditions are elaborated. These formulas are based on parameters that are easily measured or modeled. Therefore, they are useful performance metrics for existing piezoelectric harvesters.

Renaud, M.; Elfrink, R.; Jambunathan, M.; de Nooijer, C.; Wang, Z.; Rovers, M.; Vullers, R.; van Schaijk, R.

2012-10-01

56

Design and fabrication of a linear generator for vibration energy harvesting  

Microsoft Academic Search

Energy harvesting device which scavenges energy from the ambient and powers micro systems is receiving more and more attentions. In this paper, a linear generator for vibration energy harvesting is designed and fabricated. Volume of the generator core is 60.8 cm3, the mass of the device is 338 g, and the designed resonance frequency is 41 Hz. The vibration energy

Y. C. Wang; D. Shi; J. X. Shen; K. Wang; M. J. Jin

2010-01-01

57

Equivalent damping and frequency change for linear and nonlinear hybrid vibrational energy harvesting systems  

NASA Astrophysics Data System (ADS)

A unified approximation method is derived to illustrate the effect of electro-mechanical coupling on vibration-based energy harvesting systems caused by variations in damping ratio and excitation frequency of the mechanical subsystem. Vibrational energy harvesters are electro-mechanical systems that generate power from the ambient oscillations. Typically vibration-based energy harvesters employ a mechanical subsystem tuned to resonate with ambient oscillations. The piezoelectric or electromagnetic coupling mechanisms utilized in energy harvesters, transfers some energy from the mechanical subsystem and converts it to an electric energy. Recently the focus of energy harvesting community has shifted toward nonlinear energy harvesters that are less sensitive to the frequency of ambient vibrations. We consider the general class of hybrid energy harvesters that use both piezoelectric and electromagnetic energy harvesting mechanisms. Through using perturbation methods for low amplitude oscillations and numerical integration for large amplitude vibrations we establish a unified approximation method for linear, softly nonlinear, and bi-stable nonlinear energy harvesters. The method quantifies equivalent changes in damping and excitation frequency of the mechanical subsystem that resembles the backward coupling from energy harvesting. We investigate a novel nonlinear hybrid energy harvester as a case study of the proposed method. The approximation method is accurate, provides an intuitive explanation for backward coupling effects and in some cases reduces the computational efforts by an order of magnitude.

Karami, M. Amin; Inman, Daniel J.

2011-11-01

58

Design and fabrication of a micro electromagnetic vibration energy harvester  

NASA Astrophysics Data System (ADS)

This paper presents a new micro electromagnetic energy harvester that can convert transverse vibration energy to electrical power. It mainly consists of folded beams, a permanent magnet and copper planar coils. The calculated value of the natural frequency is 274 Hz and electromagnetic simulation shows that the magnetic flux density will decrease sharply with increasing space between the magnet and coils. A prototype has been fabricated using MEMS micromachining technology. The testing results show that at the resonant frequency of 242 Hz, the prototype can generate 0.55 ?W of maximal output power with peak-peak voltage of 28 mV for 0.5g (g = 9.8 m/s2) external acceleration.

Peng, Wang; Wei, Li; Lufeng, Che

2011-10-01

59

An Explicit Linearized State-Space Technique for Accelerated Simulation of Electromagnetic Vibration Energy Harvesters  

Microsoft Academic Search

Vibration energy harvesting systems pose significant modeling and design challenges due to their mixed-technology nature, extremely low levels of available energy and disparate time scales between different parts of a complete harvester. An energy harvester is a complex system of tightly coupled components modeled in the mechanical, magnetic, as well as electrical analog and digital domains. Currently available design tools

Tom J. Kazmierski; Leran Wang; Bashir M. Al-Hashimi; Geoff V. Merrett

2012-01-01

60

Compliant bistable mechanism for low frequency vibration energy harvester inspired by auditory hair bundle structures  

NASA Astrophysics Data System (ADS)

This paper presents a bio-inspired mechanism for the performance enhancement of piezoelectric power generation in vibration energy harvesting. A compliant bistable mechanism for vibration energy harvesting was explored based on the negative stiffness inspired by the auditory hair bundle structures. The proposed mechanism consists of a compliant, four-bar linkage system to mimic the hair bundle structure inside an inner ear. Our initial prototype energy harvester demonstrates that the compliant bistable mechanism featuring negative stiffness outperforms the conventional vibration energy harvester in the infra-low frequency range (1-10 Hz).

Kim, Gi-Woo; Kim, Jaehwan

2013-01-01

61

Piezoelectric MEMS energy harvesting systems driven by harmonic and random vibrations  

Microsoft Academic Search

Switching power conditioning techniques are known to greatly enhance the performance of linear piezoelectric energy harvesters subject to harmonic vibrations. With such circuits, little is known about the effect of mechanical stoppers that limit the motion or about waveforms other than harmonic vibrations. This work presents SPICE simulations of piezoelectric micro energy harvester systems that differ in choice of power

Lars-Cyril Blystad; Einar Halvorsen; Svein Husa

2010-01-01

62

New DRIE-Patterned Electrets for Vibration Energy Harvesting  

NASA Astrophysics Data System (ADS)

This paper is about a new manufacturing process aimed at developing stable SiO2/Si3N4 patterned electrets using a Deep Reactive Ion Etching (DRIE) step for an application in electret-based Vibration Energy Harvesters (e-VEH). This process consists in forming continuous layers of SiO2/Si3N4 electrets in order to limit surface conduction phenomena and is a new way to see the problem of electret patterning. Experimental results prove that patterned electrets charged by a positive corona discharge show excellent stability with high surface charge densities that may reach 5mC/m2 on 1.1?m-thick layers, even with fine patterning and harsh temperature conditions (up to 250°C). This paves the way to new e-VEH designs and manufacturing processes.

Boisseau, S.; Duret, A.-B.; Chaillout, J.-J.; Despesse, G.

2012-10-01

63

A micro electromagnetic generator for vibration energy harvesting  

NASA Astrophysics Data System (ADS)

Vibration energy harvesting is receiving a considerable amount of interest as a means for powering wireless sensor nodes. This paper presents a small (component volume 0.1 cm3, practical volume 0.15 cm3) electromagnetic generator utilizing discrete components and optimized for a low ambient vibration level based upon real application data. The generator uses four magnets arranged on an etched cantilever with a wound coil located within the moving magnetic field. Magnet size and coil properties were optimized, with the final device producing 46 µW in a resistive load of 4 k? from just 0.59 m s-2 acceleration levels at its resonant frequency of 52 Hz. A voltage of 428 mVrms was obtained from the generator with a 2300 turn coil which has proved sufficient for subsequent rectification and voltage step-up circuitry. The generator delivers 30% of the power supplied from the environment to useful electrical power in the load. This generator compares very favourably with other demonstrated examples in the literature, both in terms of normalized power density and efficiency.

Beeby, S. P.; Torah, R. N.; Tudor, M. J.; Glynne-Jones, P.; O'Donnell, T.; Saha, C. R.; Roy, S.

2007-07-01

64

Modeling and analysis of piezoelectric bimorph cantilever used for vibration energy harvesting  

Microsoft Academic Search

Piezoelectric vibration energy harvester has the advantage of high power density, and is promising in self-powered wireless sensor networks. The electromechanical coupling model has been formulated for cantilever bimorph vibration energy harvester under capacitive loads using piezoelectric theory and Euler-Bernoulli beam theory. Simulink simulation is used to obtain the steady-state characteristics, and the relationship between maximum output power, vibration frequency

Tao Yang; Yi Lin; Xianji Tan; Yuehui Feng

2010-01-01

65

Modeling of magnetic vibrational energy harvesters using equivalent circuit representations  

Microsoft Academic Search

This paper develops and analyzes an equivalent circuit model of magnetic energy harvesters using reduced-order lumped element modeling (LEM) methods. This model is intended to enhance the design and analysis of a magnetic energy harvesting system by enabling direct physical insight into the system dynamics and simple circuit analysis techniques to extract all relevant performance parameters. Moreover, the model provides

Shuo Cheng; Naigang Wang; David P. Arnold

2007-01-01

66

Vibration Based Electromagnetic Energy Harvesting - Microgenerator, Power Conversion and Control  

NASA Astrophysics Data System (ADS)

Energy harvesting has been a research focus for many years. The idea that energy can be harvested from ambient environment and a device can operate without a battery is very attractive for low power electronic applications. The slow growth of battery technology and development of low power semiconductor technology has positioned energy harvesting as a feasible power source for low power applications. The present work emphasizes on microgenerator design and power processing circuits for electromagnetic energy harvesting. The main objective is to develop a complete system for low voltage electromagnetic energy harvesting. The thesis work has been designed and developed in consecutive stages – (a) novel converter topologies for low voltage microgenerators, (b) unified design of microgenerators and converter topologies, (c) design of efficient auxiliary circuits, (d) optimal energy harvesting control. A number of suitable converter topologies are first presented for low voltage, low power energy harvesting. Their operation, analysis and modeling are discussed in detail. The loss analysis is developed to properly characterize the performance of different converters developed in this thesis. Multiple methods to interface the microgenerator with the converters are presented. Based on the interface mechanism, a suitable unified design approach is also formulated for both the microgenerator and the converters. To realize a self-sufficient energy harvesting system, design of auxiliary circuits like start-up circuits, controller and gate driver circuits is very important. In this work, they are fabricated to consume very low power while satisfying the converter requirements. Finally, a new low power control system is developed to maximize the output of the energy harvesting system. Two types of control are envisaged in this work. The first type is a simpler voltage regulation mechanism. The second, more interesting type of control is based on controlling the converter to maximize the harvested energy from the source.

Dayal, Rohan

67

Modeling of magnetic vibrational energy harvesters using equivalent circuit representations  

NASA Astrophysics Data System (ADS)

This paper develops and analyzes an equivalent circuit model of magnetic energy harvesters using reduced-order lumped element modeling (LEM) methods. This model is intended to enhance the design and analysis of a magnetic energy harvesting system by enabling direct physical insight into the system dynamics and simple circuit analysis techniques to extract all relevant performance parameters. Moreover, the model provides the ability to use circuit simulation software (e.g. PSPICE) to model the entire system in conjunction with nonlinear and/or active power electronic circuits. The circuit model is experimentally validated through electrical and mechanical measurements on a prototypical electromagnetic energy harvester.

Cheng, Shuo; Wang, Naigang; Arnold, David P.

2007-11-01

68

Electromagnetic energy harvesting from vibrations of multiple frequencies  

Microsoft Academic Search

A novel multi-frequency energy harvester has been designed and fabricated, which consists of three permanent magnets, three sets of two-layer copper coils and a supported beam of acrylic, while these coils are made of thin fire resistant 4 (FR4) substrates using a standard printed circuit board. The energy under the first, second and third resonant modes can be harvested, corresponding

Bin Yang; Chengkuo Lee; Wenfeng Xiang; Jin Xie; Johnny Han He; Rama Krishna Kotlanka; Siew Ping Low; Hanhua Feng

2009-01-01

69

A hybrid electromagnetic energy harvesting device for low frequency vibration  

NASA Astrophysics Data System (ADS)

An electromagnetic energy harvesting device, which converts a translational base motion into a rotational motion by using a rigid bar having a moving mass pivoted on a hinged point with a power spring, has been recently developed for use of civil engineering structures having low natural frequencies. The device utilizes the relative motion between moving permanent magnets and a fixed solenoid coil in order to harvest electrical power. In this study, the performance of the device is enhanced by introducing a rotational-type generator at a hinged point. In addition, a mechanical stopper, which makes use of an auxiliary energy harvesting part to further improve the efficiency, is incorporated into the device. The effectiveness of the proposed hybrid energy harvesting device based on electromagnetic mechanism is verified through a series of laboratory tests.

Jung, Hyung-Jo; Kim, In-Ho; Min, Dong Yi; Sim, Sung-Han; Koo, Jeong-Hoi

2013-04-01

70

Micro-scale piezoelectric vibration energy harvesting: From fixed-frequency to adaptable-frequency devices  

NASA Astrophysics Data System (ADS)

Wireless sensor networks (WSNs) have the potential to transform engineering infrastructure, manufacturing, and building controls by allowing condition monitoring, asset tracking, demand response, and other intelligent feedback systems. A wireless sensor node consists of a power supply, sensor(s), power conditioning circuitry, radio transmitter and/or receiver, and a micro controller. Such sensor nodes are used for collecting and communicating data regarding the state of a machine, system, or process. The increasing demand for better ways to power wireless devices and increase operation time on a single battery charge drives an interest in energy harvesting research. Today, wireless sensor nodes are typically powered by a standard single-charge battery, which becomes depleted within a relatively short timeframe depending on the application. This introduces tremendous labor costs associated with battery replacement, especially when there are thousands of nodes in a network, the nodes are remotely located, or widely-distributed. Piezoelectric vibration energy harvesting presents a potential solution to the problems associated with too-short battery life and high maintenance requirements, especially in industrial environments where vibrations are ubiquitous. Energy harvester designs typically use the harvester to trickle charge a rechargeable energy storage device rather than directly powering the electronics with the harvested energy. This allows a buffer between the energy harvester supply and the load where energy can be stored in a "tank". Therefore, the harvester does not need to produce the full required power at every instant to successfully power the node. In general, there are tens of microwatts of power available to be harvested from ambient vibrations using micro scale devices and tens of milliwatts available from ambient vibrations using meso scale devices. Given that the power requirements of wireless sensor nodes range from several microwatts to about one hundred milliwatts and are falling steadily as improvements are made, it is feasible to use energy harvesting to power WSNs. This research begins by presenting the results of a thorough survey of ambient vibrations in the machine room of a large campus building, which found that ambient vibrations are low frequency, low amplitude, time varying, and multi-frequency. The modeling and design of fixed-frequency micro scale energy harvesters are then presented. The model is able to take into account rotational inertia of the harvester's proof mass and it accepts arbitrary measured acceleration input, calculating the energy harvester's voltage as an output. The fabrication of the micro electromechanical system (MEMS) energy harvesters is discussed and results of the devices harvesting energy from ambient vibrations are presented. The harvesters had resonance frequencies ranging from 31 - 232 Hz, which was the lowest reported in literature for a MEMS device, and produced 24 pW/g2 - 10 nW/g2 of harvested power from ambient vibrations. A novel method for frequency modification of the released harvester devices using a dispenser printed mass is then presented, demonstrating a frequency shift of 20 Hz. Optimization of the MEMS energy harvester connected to a resistive load is then presented, finding that the harvested power output can be increased to several microwatts with the optimized design as long as the driving frequency matches the harvester's resonance frequency. A framework is then presented to allow a similar optimization to be conducted with the harvester connected to a synchronously switched pre-bias circuit. With the realization that the optimized energy harvester only produces usable amounts of power if the resonance frequency and driving frequency match, which is an unrealistic situation in the case of ambient vibrations which change over time and are not always known a priori, an adaptable-frequency energy harvester was designed. The adaptable-frequency harvester works by taking advantage of the coupling between

Miller, Lindsay Margaret

71

Vibration Energy Harvesting for Disaster Asset Monitoring Using Active RFID Tags  

Microsoft Academic Search

This paper highlights the importance of energy harvesting in high-value asset monitoring applications involving use of active RFID tags. The paper begins by highlighting advantages of active tags including improved range and read rate in electromagnetically unfriendly environments. Although a battery can substantially improve performance, it limits maintenance-free operational life. Therefore, harvesting energy from sources such as vibration is shown

Abhiman Hande; Raj Bridgelall; Ben Zoghi

2010-01-01

72

Evaluation of coupled piezoelectric and electromagnetic technique for vibration energy harvesting  

Microsoft Academic Search

Vibration energy harvesting is an attractive technique for potential powering of wireless sensors and other low power micro devices. In order for the device to have maximum power output, it is necessary to match electrical and mechanical damping. In this work a coupled piezoelectric and electromagnetic energy harvesting device is evaluated for its efficiency and compared with optimized standalone piezoelectric

Vinod R. Challa; M. G. Prasad; Frank T. Fisher

2008-01-01

73

AlN-based MEMS devices for vibrational energy harvesting applications  

Microsoft Academic Search

This paper presents a new AlN-based MEMS devices suitable for vibrational energy harvesting applications. Due to their particular shape and unlike traditional cantilever which efficiently harvest energy only if subjected to stimulus in the proper direction, the proposed devices have 3D generation capabilities solving the problem of device orientation and placement in real applications. Thanks to their particular shape, the

A. Bertacchini; S. Scorcioni; D. Dondi; L. Larcher; P. Pavan; M. T. Todaro; A. Campa; G. Caretto; S. Petroni; A. Passaseo; M. De Vittorio

2011-01-01

74

Accelerated simulation of tunable vibration energy harvesting systems using a linearised state-space technique  

Microsoft Academic Search

This paper proposes a linearised state-space tech- nique to accelerate the simulation of tunable vibration energy harvesting systems by at least two orders of magnitude. The paper provides evidence that currently available simulation tools are inadequate for simulating complete energy harvesting systems where prohibitive CPU times are encountered due to disparate time scales. In the proposed technique, the model of

Leran Wang; Tom J. Kazmierski; Bashir M. Al-Hashimi; Alex S. Weddell; Geoff V. Merrett; Ivo N. Ayala Garcia

2011-01-01

75

An automated design flow for vibration-based energy harvester systems  

Microsoft Academic Search

This paper proposes, for the first time, an automated energy harvester design flow which is based on a single HDL software platform that can be used to model, simulate, configure and optimise energy harvester systems. A demonstrator pro- totype incorporating an electromagnetic mechanical-vibration- based micro-generator and a limited number of library models has been developed and a design case study

Leran Wang; Tom J. Kazmierski; Bashir M. Al-hashimi; Stephen P. Beeby; Dibin Zhu

2009-01-01

76

DESIGN CONSIDERATIONS FOR MEMS-SCALE PIEZOELECTRIC MECHANICAL VIBRATION ENERGY HARVESTERS  

Microsoft Academic Search

Design considerations for piezoelectric-based energy harvesters for MEMS-scale sensors are presented, including a review of past work. Harvested ambient vibration energy can satisfy power needs of advanced MEMS-scale autonomous sensors for numerous applications, e.g., structural health monitoring. Coupled 1-D and modal (beam structure) electromechanical models are presented to predict performance, especially power, from measured low-level ambient vibration sources. Models are

NOËL E. DUTOIT; BRIAN L. WARDLE; SANG-GOOK KIM

2005-01-01

77

Limit Cycle Oscillations of a Nonlinear Piezo-magneto-elastic Structure for Broadband Vibration Energy Harvesting  

Microsoft Academic Search

\\u000a Vibration-based energy harvesting has been investigated by several researchers over the last decade. Typically, devices employing\\u000a piezoelectric, electromagnetic, electrostatic and magnetostrictive transductions have been designed in order to convert ambient\\u000a vibrations into electricity under resonance excitation. Regardless of the transduction mechanism, a primary issue in resonant\\u000a energy harvesters is that the best performance of the device is limited to resonance

A. Erturk; J. Hoffmann; D. J. Inman

78

A vibration-based electromagnetic energy harvester system with highly efficient interface electronics  

Microsoft Academic Search

This paper presents a vibration-based electromagnetic (EM) energy harvester system utilizing novel and highly efficient interface electronics. The energy harvesting module up-converts the environmental low frequency vibrations for increased AC power output. The interface circuit employs a boot-strap technique to reduce the threshold voltage of the rectifiers further increasing the power conversion efficiency of the overall system. The complete system,

Arian Rahimi; Ozge Zorlu; Ali Muhtaroglu; Haluk Kulah

2011-01-01

79

An interface circuit prototype for a vibration-based electromagnetic energy harvester  

Microsoft Academic Search

This paper describes the interface electronics for a vibration based Electromagnetic (EM) energy harvester, which works on the mechanical frequency-up-conversion principle. The interface electronics is used to step up and rectify the harvested AC signal of the energy harvester through a two-stage charge-pump circuit. Output voltage of 4.5 V with 2.5% ripple has been demonstrated at a load current of

Arian Rahimi; Ozge Zorlu; Haluk Kulah; Ali Muhtaroglu

2010-01-01

80

Piezoelectric-based power sources for harvesting energy from platforms with low-frequency vibration  

NASA Astrophysics Data System (ADS)

This paper presents a new class of highly efficient piezoelectric based energy harvesting power sources for mounting on platforms that vibrate at very low frequencies as compared to the frequencies at which energy can be efficiently harvested using piezoelectric elements . These energy harvesting power sources have a very simple design and do not require accurate tuning for each application to match the frequency of the platform vibration. The developed method of harvesting mechanical energy and converting it to electrical energy overcomes problems that are usually encountered with harvesting energy from low frequency vibration of various platforms such as ships and other platforms with similar vibratory (rocking or translational) motions. Omnitek Partners has designed several such energy harvesting power sources and is in the process of constructing prototypes for testing. The developed designs are modular and can be used to construct power sources for various power requirements. The amount of mechanical energy available for harvesting is obviously dependent on the frequency and amplitude of vibration of the platform, and the size and mass of the power source.

Rastegar, J.; Pereira, C.; Nguyen, H.-L.

2006-04-01

81

Analysis of frequency up-conversion based vibration energy harvesting  

Microsoft Academic Search

Mechanical frequency up-conversion has been suggested by many researchers in order to increase power density of kinetic energy harvesters. In this paper analytical analysis of frequency up-conversion mechanism has been carried out in some detail. It has been shown that sources of actuation for a frequency increased generator can be categorized as force limited and displacement limited sources. Maximum energy

Khalid Ashraf; John Ojur Dennis

2011-01-01

82

MEMS Vibration Energy Harvesting Devices With Passive Resonance Frequency Adaptation Capability  

Microsoft Academic Search

Further advancement of ambient mechanical vibration energy harvesting depends on finding a simple yet efficient method of tuning the resonance frequency of the harvester to match the one dominant in the environment. We propose an innovative approach to achieve a completely passive, wideband adaptive system by employing mechanical nonlinear strain stiffening. We present analytical analysis of the underlying idea as

Marcin Marzencki; Maxime Defosseux; Skandar Basrour

2009-01-01

83

A two-mass cantilever beam model for vibration energy harvesting applications  

Microsoft Academic Search

While vibration energy harvesting has become a viable means to power wireless sensors, narrow bandwidth is still a hurdle to the practical use of the technology. For conventional piezoelectric or electromagnetic harvesters, having multiple proof masses mounted on a beam is one way to widen the effective bandwidth. This is because the addition of proof masses increases the number of

Qing Ou; XiaoQi Chen; Stefanie Gutschmidt; Alan Wood; Nigel Leigh

2010-01-01

84

Linear and nonlinear energy harvesters for powering pacemakers from heart beat vibrations  

NASA Astrophysics Data System (ADS)

Linear and nonlinear piezoelectric devices are introduced to continuously recharge the batteries of the pacemakers by converting the vibrations from the heartbeats to electrical energy. The power requirement of the pacemakers is very low. At the same time, after about 10 years from the original implantation of the pacemakers, patients have to go through another surgical operation just to replace the batteries of their pacemakers. We investigate using vibration energy harvesters to significantly increase the battery life of the pace makers. The major source of vibrations in chest area is due to heartbeats. Linear low frequency and nonlinear mono-stable and bi-stable energy harvesters are designed according to especial signature of heart vibrations. The proposed energy harvesters are robust to variations of heart beat frequency and can meet the power requirement of the pacemakers.

Karami, M. Amin; Inman, Daniel J.

2011-03-01

85

Mechanical analysis of piezoelectric vibration energy harvesting devices  

Microsoft Academic Search

A modal model of the dynamics behavior of a bimorph vibration energy scavenger aimed at wireless system networks is proposed and validated via FEM simulations. Experimental set-ups are developed with the aim of assessing the validity of the model. The set-ups are tested by measuring the performances of commercially available energy scavengers. Repetitive bending tests allow determining the equivalent bending

D. Blazevic; S. Zelenika; G. Gregov

2010-01-01

86

Design of nonlinear springs for wideband magnetic vibration energy harvester  

Microsoft Academic Search

This paper compares four nonlinear springs for the micro power generator (MPG) application which convert low level vibration energy into electrical power. The magnet-spring system decides the generator's resonant frequency, and this work proves that the spring's nonlinearity level influences the width of the operating frequency. The four different planar springs have the same outer\\/inner dimensions and the same linear

Linghe Sui; Xuhan Dai; Xiaolin Zhao; Peihong Wang; Hailin Zhou

2011-01-01

87

Energy harvesting from underwater torsional vibrations of a patterned ionic polymer metal composite  

NASA Astrophysics Data System (ADS)

In this paper, we study underwater energy harvesting from torsional vibrations of an ionic polymer metal composite (IPMC) with patterned electrodes. We focus on harmonic base excitation of a centimeter-size IPMC, which is modeled as a slender beam with thin cross-section vibrating in a viscous fluid. Large-amplitude torsional vibrations are described using a complex hydrodynamic function, which accounts for added mass and nonlinear hydrodynamic damping from the surrounding fluid. A linear black box model is utilized to predict the IPMC electrical response as a function of the total twist angle. Model parameters are identified from in-air transient response, underwater steady-state vibrations, and electrical discharge experiments. The resulting electromechanical model allows for predicting energy harvesting from the IPMC as a function of the shunting resistance and the frequency and amplitude of the base excitation. Model results are validated against experimental findings that demonstrate power harvesting densities on the order of picowatts per millimeter cubed.

Cha, Youngsu; Shen, Linfeng; Porfiri, Maurizio

2013-05-01

88

Electromagnetic vibration energy harvesting with high power density using a magnet array  

NASA Astrophysics Data System (ADS)

Electromagnetic vibration energy harvesters have been widely used to convert the vibration energy into electricity. However, one of the main challenges of using electromagnetic vibration energy harvesters is that they are usually in very large size with low power density. In this paper, a new type of electromagnetic vibration energy harvester with remarkably high power density is developed. By putting the strong rare-earth magnets in alternating directions and using high-magnetic-conductive casing, magnetic flux density up to 0.9T are obtained. This configuration also has a small current loop with less electrical reluctance, which further increases the high power density when the coil is designed to follow the current loop. The prototype, the size of which is 142x140x86 mm3, can provided up to 727Ns/m damping coefficient, which means 428 kNs/m4 damping density when it is shunt with 70? external resistive load which is set to the same as the internal resistor of the harvester to achieve maximum power. The corresponding power density is 725 ?W/cm3 at 15HZ harmonic force excitation of 2.54mm peak-to-peak amplitude. When shot-circuited, 1091Ns/m damping coefficient and 638 kNs/m4 damping density is achieved. The effectiveness of this novel vibration energy harvester is shown both by FEA and experiments. The eddy current damper is also discussed in this paper for comparison. The proposed configuration of the magnet array can also be extended for both micro-scale and large-scale energy harvesting applications, such as vibration energy harvesting from tall buildings, long bridges and railways.

Tang, Xiudong; Lin, Teng; Zuo, Lei

2012-03-01

89

Piezoelectric MEMS energy harvesting systems driven by harmonic and random vibrations.  

PubMed

Switching power conditioning techniques are known to greatly enhance the performance of linear piezoelectric energy harvesters subject to harmonic vibrations. With such circuits, little is known about the effect of mechanical stoppers that limit the motion or about waveforms other than harmonic vibrations. This work presents SPICE simulations of piezoelectric micro energy harvester systems that differ in choice of power conditioning circuits and stopper models. We consider in detail both harmonic and random vibrations. The nonlinear switching conversion circuitry performs better than simple passive circuitry, especially when mechanical stoppers are in effect. Stopper loss is important under broadband vibrations. Stoppers limit the output power for sinusoidal excitations, but result in the same output power whether the stoppers are lossy or not. When the mechanical stoppers are hit by the proof mass during high-amplitude vibrations, nonlinear effects such as saturation and jumps are present. PMID:20378453

Blystad, Lars-Cyril; Halvorsen, Einar; Husa, Svein

2010-04-01

90

Vacuum-packaged piezoelectric vibration energy harvesters: damping contributions and autonomy for a wireless sensor system  

NASA Astrophysics Data System (ADS)

This paper describes the characterization of thin-film MEMS vibration energy harvesters based on aluminum nitride as piezoelectric material. A record output power of 85 µW is measured. The parasitic-damping and the energy-harvesting performances of unpackaged and packaged devices are investigated. Vacuum and atmospheric pressure levels are considered for the packaged devices. When dealing with packaged devices, it is found that vacuum packaging is essential for maximizing the output power. Therefore, a wafer-scale vacuum package process is developed. The energy harvesters are used to power a small prototype (1 cm3 volume) of a wireless autonomous sensor system. The average power consumption of the whole system is less than 10 µW, and it is continuously provided by the vibration energy harvester.

Elfrink, R.; Renaud, M.; Kamel, T. M.; de Nooijer, C.; Jambunathan, M.; Goedbloed, M.; Hohlfeld, D.; Matova, S.; Pop, V.; Caballero, L.; van Schaijk, R.

2010-10-01

91

Diamagnetic levitation for nonlinear vibration energy harvesting: Theoretical modeling and analysis  

NASA Astrophysics Data System (ADS)

This paper provides theoretical modeling and analysis of applying diamagnetic levitation for nonlinear vibration energy harvesting in detail by first identifying potential merits as well as limitations. Based on a magnetic dipole model, analytical analysis is conducted by providing simplified analytical expressions of restoring forces and electromagnetic damping which are then transformed into a hardening spring model and results in a Duffing equation with strong nonlinearity. In addition, constraints on physical geometry are discussed and derived in the view of practical energy harvester design. More importantly, the derivation and discussion extended to multi-well potential suggest that diamagnetic levitation may enable designing an energy harvester that subject to cross-well chaos with a compact volume and wideband responses. Without mechanical damping in any form, diamagnetic levitation may be considered as a promising mechanism for developing vibration energy harvesters with great performance, and the paper provides a technology push on the possibility.

Liu, Lei; Yuan, F. G.

2013-01-01

92

Harvestable vibrational energy from an avian source: theoretical predictions vs. measured values  

NASA Astrophysics Data System (ADS)

For many reasons, it would be beneficial to have the capability of powering a wildlife tag over the course of multiple migratory seasons. Such an energy harvesting system would allow for more data collection and eliminate the need to replace depleted batteries. In this work, we investigate energy harvesting on birds and focus on vibrational energy harvesting. We review a method of predicting the amount of power that can be safely harvested from the birds such that the effect on their longterm survivability is not compromised. After showing that the safely harvestable power is significant in comparison to the circuits used in avian tags, we present testing results for the flight accelerations of two species of birds. Using these measured values, we then design harvesters that matched the flight acceleration frequency and are sufficiently low mass to be carried by the birds.

Shafer, Michael W.; MacCurdy, Robert; Garcia, Ephrahim; Winkler, David

2012-03-01

93

Investigation of concurrent energy harvesting from ambient vibrations and wind using a single piezoelectric generator  

NASA Astrophysics Data System (ADS)

In this letter, a single vibratory energy harvester integrated with an airfoil is proposed to concurrently harness energy from ambient vibrations and wind. In terms of its transduction capabilities and power density, the integrated device is shown to have a superior performance under the combined loading when compared to utilizing two separate devices to harvest energy independently from the two available energy sources. Even below its flutter speed, the proposed device was able to provide 2.5 times the power obtained using two separate harvesters.

Bibo, A.; Daqaq, M. F.

2013-06-01

94

Powering pacemakers from heartbeat vibrations using linear and nonlinear energy harvesters  

NASA Astrophysics Data System (ADS)

Linear and nonlinear piezoelectric devices are introduced to continuously recharge the batteries of the pacemakers by converting the vibrations from the heartbeats to electrical energy. The power requirement of a pacemaker is very low. However, after few years, patients require another surgical operation just to replace their pacemaker battery. Linear low frequency and nonlinear mono-stable and bi-stable energy harvesters are designed according to the especial signature of heart vibrations. The proposed energy harvesters are robust to variation of heart rate and can meet the power requirement of pacemakers.

Amin Karami, M.; Inman, Daniel J.

2012-01-01

95

Screen printed PZT\\/PZT thick film bimorph MEMS cantilever device for vibration energy harvesting  

Microsoft Academic Search

We present a MEMS-based PZT\\/PZT thick film bimorph vibration energy harvester with an integrated silicon proof mass. The most common piezoelectric energy harvesting devices utilize a cantilever beam of a non piezoelectric material as support beneath or in-between the piezoelectric material. It provides mechanical support but it also reduces the power output. Our device replaces the support with another layer

R. Xu; A. Lei; T. L. Christiansen; K. Hansen; M. Guizzetti; K. Birkelund; E. V. Thomsen; O. Hansen

2011-01-01

96

Broadband electromagnetic vibration energy harvesting system for powering wireless sensor nodes  

NASA Astrophysics Data System (ADS)

This paper reports the design of an electromagnetic vibration energy harvesting system that provides high power density and broad bandwidth. The ‘double cell’ harvester was chosen as the generator for this system. In order to harvest power over a broad range of frequencies, four ‘double cell’ harvesters with varying resonances were incorporated in the system architecture. The average AC to regulated DC power conversion efficiency across the 4 Hz bandwidth was 78%, which is one of the highest reported magnitudes for an electromagnetic vibration harvesting system. The magnetic flux density variation within the double cell array was modeled using the finite element method and compared to a single cell with equivalent tip mass and magnet volume. The double cell array was found to generate a similar magnitude of power to a single cell but three times higher bandwidth. The average generator conversion efficiency for the double cell array was 45.3%, which approaches the maximum theoretical limit of 50%.

Marin, Anthony; Turner, John; Ha, Dong Sam; Priya, Shashank

2013-07-01

97

A micro electromagnetic low level vibration energy harvester based on MEMS technology  

Microsoft Academic Search

This paper presents a micro electromagnetic energy harvester which can convert low level vibration energy to electrical power.\\u000a It mainly consists of an electroplated copper planar spring, a permanent magnet and a copper planar coil with high aspect\\u000a ratio. Mechanical simulation shows that the natural frequency of the magnet-spring system is 94.5 Hz. The resonant vibration\\u000a amplitude of the magnet is

Peihong Wang; Katsuhiko Tanaka; Susumu Sugiyama; Xuhan Dai; Xiaolin Zhao; Jingquan Liu

2009-01-01

98

Electromagnetic energy harvester with repulsively stacked multilayer magnets for low frequency vibrations  

NASA Astrophysics Data System (ADS)

This paper investigates the applicability of an electromagnetic generator with repulsively stacked magnets for harvesting energy from traffic-induced bridge vibrations. First, the governing equation for electro-mechanical coupling is presented. The magnetic field for repulsive pole arrangements is discussed and the model is validated from a magnet falling test. The detailed design, fabrication, and test results of a prototype device are presented in the paper. An experimental vibration shaker test is conducted to assess the performance of the energy harvester. Field test and numerical simulation at the 3rd Nongro Bridge in South Korea shows that the device can generate an average power of 0.12 mW from an input rms acceleration of 0.25 m s-2 at 4.10 Hz. With further frequency tuning and design improvement, an average power of 0.98 mW could be potentially harvested from the ambient vibration of the bridge.

Kwon, Soon-Duck; Park, Jinkyoo; Law, Kincho

2013-05-01

99

Design and simulation of SOI-MEMS electrostatic vibration energy harvester for micro power generation  

Microsoft Academic Search

The micro power generation using vibration energy sources appears to be attractive due to its applicability on many situations and environmental conditions. The electrostatic energy harvester has various advantageous over piezoelectric and electromagnetic systems such as reduction in fabrication process complexity and cost, feasibility on MEMS and IC integration, improves the possibility level of integration with silicon based microelectronics and

Othman Sidek; Muhammad Afif Khalid; Mohammad Zulfikar Ishak; Muhamad Azman Miskam

2011-01-01

100

Simulation of an Electrostatic Energy Harvester at Large Amplitude Narrow and Wide Band Vibrations  

Microsoft Academic Search

An electrostatic in-plane overlap varying energy harvester is modeled and simulated using a circuit simulator. Both linear and nonlinear models are investigated. The nonli- near model includes mechanical stoppers at the displacement extremes. Large amplitude excitation signals, both narrow and wide band, are used to emulate environmental vibrations. Non- linear behavior is significant at large displacement due to the impact

Lars Geir Whist Tvedt; Lars-cyril Julin Blystad; Einar Halvorsen

2008-01-01

101

Self-powered autonomous wireless sensor node using vibration energy harvesting  

Microsoft Academic Search

This paper reports the development and implementation of an energy aware autonomous wireless condition monitoring sensor system (ACMS) powered by ambient vibrations. An electromagnetic (EM) generator has been designed to harvest sufficient energy to power a radio-frequency (RF) linked accelerometer-based sensor system. The ACMS is energy aware and will adjust the measurement\\/transmit duty cycle according to the available energy; this

R. Torah; P. Glynne-Jones; M. Tudor; T. O'Donnell; S. Roy; S. Beeby

2008-01-01

102

Self-powered autonomous wireless sensor node using vibration energy harvesting  

Microsoft Academic Search

This paper reports the development and implementation of an energy aware autonomous wireless condition monitoring sensor system (ACMS) powered by ambient vibrations. An electromagnetic (EM) generator has been designed to harvest sufficient energy to power a radio-frequency (RF) linked accelerometer-based sensor system. The ACMS is energy aware and will adjust the measurement\\/transmit duty cycle according to the available energy; this

103

A wideband, frequency up-converting bounded vibration energy harvester for a low-frequency environment  

NASA Astrophysics Data System (ADS)

This paper presents a bounded vibration energy harvester to effectively harvest energy from a wide band of low-frequency environmental vibrations ranging from 10 to 18 Hz. Rigid mechanical stoppers are used to confine the seismic mass movement within the elastic limits of the spring. Experimental results show the effectiveness of the proposed technique in increasing the efficiency of the energy harvester. When excited at a frequency of 10 Hz with a peak acceleration of 1 g, the harvester responds at a higher frequency of 20 Hz and gives a peak power of 2.68 mW and a peak to peak voltage of 2.62 V across a load of 220 ?. The average power density of 65.74 ?W cm-3 obtained at 10 Hz 1 g excitation monotonically increases with frequency up to 341.86 ?W cm-3 at 18 Hz. An analytical model describing the nonlinear dynamics of the proposed harvester is also presented. A simple technique to estimate the energy losses during impact and thereof a method to incorporate these losses in the model are suggested. The presented model not only predicts the experimental voltage waveform and frequency response of the device with good similarity but also predicts the RMS voltage from the harvester for the whole range of operating frequencies with an RMS error of 5.2%.

Ashraf, K.; Khir, M. H. Md; Dennis, J. O.; Baharudin, Z.

2013-02-01

104

Fabrication and characterization of MEMS-based PZT/PZT bimorph thick film vibration energy harvesters  

NASA Astrophysics Data System (ADS)

We describe the fabrication and characterization of a significantly improved version of a microelectromechanical system-based PZT/PZT thick film bimorph vibration energy harvester with an integrated silicon proof mass; the harvester is fabricated in a fully monolithic process. The main advantage of bimorph vibration energy harvesters is that strain energy is not lost in mechanical support materials since only Pb(ZrxTi1-x)O3 (PZT) is strained; as a result, the effective system coupling coefficient is increased, and thus a potential for significantly higher output power is released. In addition, when the two layers are connected in series, the output voltage is increased, and as a result the relative power loss in the necessary rectifying circuit is reduced. We describe an improved process scheme for the energy harvester, which resulted in a robust fabrication process with a record high fabrication yield of 98%. The robust fabrication process allowed a high pressure treatment of the screen printed PZT thick films prior to sintering. The high pressure treatment improved the PZT thick film performance and increased the harvester power output to 37.1 ?W at 1 g root mean square acceleration. We also characterize the harvester performance when only one of the PZT layers is used while the other is left open or short circuit.

Xu, R.; Lei, A.; Dahl-Petersen, C.; Hansen, K.; Guizzetti, M.; Birkelund, K.; Thomsen, E. V.; Hansen, O.

2012-09-01

105

The role of coupling strength in the performance of electrodynamic vibrational energy harvesters  

NASA Astrophysics Data System (ADS)

This paper explores the role of a key dimensionless design parameter, denoted ‘coupling strength’, that governs the power generation performance of electrodynamic (electromagnetic) vibrational energy harvesters. The importance of coupling strength—and not just the electrodynamic transduction coefficient—on the output power and efficiency of the vibration energy harvesting device is presented analytically using a standard electromechanical model and validated using experimental results. It is shown that, up to a certain point, increasing the coupling strength of the harvester substantially increases the output power, resulting in improved electrodynamic coupling effectiveness and device efficiency. An electrodynamic harvester is designed such that the coupling strength can be varied through manual adjustments without altering the input vibration characteristics. Experimentally, the harvester is tested at a constant input acceleration amplitude of 0.74 m s-2 at the device natural frequency of 28.1 Hz. By increasing the coupling strength of the device from 2.6 to 49.2, the output power increased from 0.64 to 1.06 mW. The corresponding electrodynamic coupling effectiveness increased from 0.53 to 0.92, and the mechanical-to-electrical device efficiency increased from 21% to 45.3%.

Challa, Vinod R.; Cheng, Shuo; Arnold, David P.

2013-02-01

106

An energy harvester using piezoelectric cantilever beams undergoing coupled bending-torsion vibrations  

NASA Astrophysics Data System (ADS)

Recently, piezoelectric cantilevered beams have received considerable attention for vibration-to-electric energy conversion. Generally, researchers have investigated a classical piezoelectric cantilever beam with or without a tip mass. In this paper, we propose the use of a unimorph cantilever beam undergoing bending-torsion vibrations as a new piezoelectric energy harvester. The proposed design consists of a single piezoelectric layer and a couple of asymmetric tip masses; the latter convert part of the base excitation force into a torsion moment. This structure can be tuned to be a broader band energy harvester by adjusting the first two global natural frequencies to be relatively close to each other. We develop a distributed-parameter model of the harvester by using the Euler-beam theory and Hamilton's principle, thereby obtaining the governing equations of motion and associated boundary conditions. Then, we calculate the exact eigenvalues and associated mode shapes and validate them with a finite element (FE) model. We use these mode shapes in a Galerkin procedure to develop a reduced-order model of the harvester, which we use in turn to obtain closed-form expressions for the displacement, twisting angle, voltage output, and harvested electrical power. These expressions are used to conduct a parametric study for the dynamics of the system to determine the appropriate set of geometric properties that maximizes the harvested electrical power. The results show that, as the asymmetry is increased, the harvester's performance improves. We found a 30% increase in the harvested power with this design compared to the case of beams undergoing bending only. We also show that the locations of the two masses can be chosen to bring the lowest two global natural frequencies closer to each other, thereby allowing the harvesting of electrical power from multi-frequency excitations.

Abdelkefi, A.; Najar, F.; Nayfeh, A. H.; Ben Ayed, S.

2011-11-01

107

Piezoelectric energy harvesting from vortex-induced vibrations of circular cylinder  

NASA Astrophysics Data System (ADS)

The concept of harvesting energy from a circular cylinder undergoing vortex-induced vibrations is investigated. The energy is harvested by attaching a piezoelectric transducer to the transverse degree of freedom. Numerical simulations are performed for Reynolds numbers (Re) in the range 96?Re?118, which covers the pre-synchronization, synchronization, and post-synchronization regimes. Load resistances (R) in the range 500??R?5M? are considered. The results show that the load resistance has a significant effect on the oscillation amplitude, lift coefficient, voltage output, and harvested power. The results also show that the synchronization region widens when the load resistance increases. It is also found that there is an optimum value of the load resistance for which the harvested power is maximum. This optimum value does not correspond to the case of largest oscillations, which points to the need for a coupled analysis as performed here.

Mehmood, A.; Abdelkefi, A.; Hajj, M. R.; Nayfeh, A. H.; Akhtar, I.; Nuhait, A. O.

2013-09-01

108

Fabrication and performance of MEMS-based piezoelectric power generator for vibration energy harvesting  

Microsoft Academic Search

A MEMS-based energy harvesting device, micro piezoelectric power generator, is designed to convert ambient vibration energy to electrical power via piezoelectric effect. In this work, the generator structure of composite cantilever with nickel metal mass is devised. Micro-electronic-mechanical systems (MEMS) related techniques such as sol–gel, RIE dry etching, wet chemical etching, UV-LIGA are developed to fabricate the device and then

Hua-bin Fang; Jing-quan Liu; Zheng-yi Xu; Lu Dong; Li Wang; Di Chen; Bing-chu Cai; Yue Liu

2006-01-01

109

Inducing bistability with local electret technology in a microcantilever based non-linear vibration energy harvester  

NASA Astrophysics Data System (ADS)

A micro-electro-mechanical system based vibration energy harvester is studied exploring the benefits of bistable non linear dynamics in terms of energy conversion. An electrostatic based approach to achieve bistability, which consists in the repulsive interaction between two electrets locally charged in both tip free ends of an atomic force microscope cantilever and a counter electrode, is experimentally demonstrated. A simple model allows the prediction of the measured dynamics of the system, which shows an optimal distance between the cantilever and the counter electrode in terms of the root mean square vibration response to a colored Gaussian excitation noise.

López-Suárez, M.; Agustí, J.; Torres, F.; Rurali, R.; Abadal, G.

2013-04-01

110

Electroelastic modeling and experimental validations of piezoelectric energy harvesting from broadband random vibrations of cantilevered bimorphs  

NASA Astrophysics Data System (ADS)

We present electroelastic modeling, analytical and numerical solutions, and experimental validations of piezoelectric energy harvesting from broadband random vibrations. The modeling approach employed herein is based on a distributed-parameter electroelastic formulation to ensure that the effects of higher vibration modes are included, since broadband random vibrations, such as Gaussian white noise, might excite higher vibration modes. The goal is to predict the expected value of the power output and the mean-square shunted vibration response in terms of the given power spectral density (PSD) or time history of the random vibrational input. The analytical method is based on the PSD of random base excitation and distributed-parameter frequency response functions of the coupled voltage output and shunted vibration response. The first of the two numerical solution methods employs the Fourier series representation of the base acceleration history in an ordinary differential equation solver while the second method uses an Euler-Maruyama scheme to directly solve the resulting electroelastic stochastic differential equations. The analytical and numerical simulations are compared with several experiments for a brass-reinforced PZT-5H bimorph under different random excitation levels. The simulations exhibit very good agreement with the experimental measurements for a range of resistive electrical boundary conditions and input PSD levels. It is also shown that lightly damped higher vibration modes can alter the expected power curve under broadband random excitation. Therefore, the distributed-parameter modeling and solutions presented herein can be used as a more accurate alternative to the existing single-degree-of-freedom solutions for broadband random vibration energy harvesting.

Zhao, S.; Erturk, A.

2013-01-01

111

Copper foil-type vibration-based electromagnetic energy harvester  

Microsoft Academic Search

This paper presents the modeling, simulation, fabrication and experimental results of a vibration-based electromagnetic power generator (EMPG). A novel, low-cost, one-mask technique is used to fabricate the planar coils and the planar spring. This fabrication technique can provide an alternative for processes such as lithographie galvanoformung abformung (LIGA) or SU-8 molding and MEMS electroplating. Commercially available copper foils of 20

Farid Khan; Farrokh Sassani; Boris Stoeber

2010-01-01

112

General model with experimental validation of electrical resonant frequency tuning of electromagnetic vibration energy harvesters  

NASA Astrophysics Data System (ADS)

This paper presents a general model and its experimental validation for electrically tunable electromagnetic energy harvesters. Electrical tuning relies on the adjustment of the electrical load so that the maximum output power of the energy harvester occurs at a frequency which is different from the mechanical resonant frequency of the energy harvester. Theoretical analysis shows that for this approach to be feasible the electromagnetic vibration energy harvester’s coupling factor must be maximized so that its resonant frequency can be tuned with the minimum decrease of output power. Two different-sized electromagnetic energy harvesters were built and tested to validate the model. Experimentally, the micro-scale energy harvester has a coupling factor of 0.0035 and an untuned resonant frequency of 70.05 Hz. When excited at 30 mg, it was tuned by 0.23 Hz by changing its capacitive load from 0 to 4000 nF its effective tuning range is 0.15 Hz for a capacitive load variation from 0 to 1500 nF. The macro-scale energy harvester has a coupling factor of 552.25 and an untuned resonant frequency of 95.1 Hz and 95.5 Hz when excited at 10 mg and 25 mg, respectively. When excited at 10 mg, it was tuned by 3.8 Hz by changing its capacitive load from 0 to 1400 nF it has an effective tuning range of 3.5 Hz for a capacitive load variation from 0 to 1200 nF. When excited at 25 mg, its resonant frequency was tuned by 4.2 Hz by changing its capacitive load from 0 to 1400 nF it has an effective tuning range of about 5 Hz. Experimental results were found to agree with the theoretical analysis to within 10%.

Zhu, Dibin; Roberts, Stephen; Mouille, Thomas; Tudor, Michael J.; Beeby, Stephen P.

2012-10-01

113

Linear and nonlinear electromagnetic coupling models in vibration-based energy harvesting  

NASA Astrophysics Data System (ADS)

This paper investigates the response of an energy harvester that uses electromagnetic induction to convert ambient vibration into electrical energy. A unique aspect of the present study is the comparison of the system's response behavior when either a linear or a physically motivated form of nonlinear coupling is applied. The motivating hypothesis for this work was that nonlinear coupling could be used to improve the performance of an energy harvester by broadening its frequency response. Combined theoretical and numerical studies investigate the harvester's response for both single and multi-frequency base excitation. Our investigations unveil regions in the parameter space where nonlinear coupling is better than linear coupling and regions where the opposite is true. The meaningful conclusion is that nonlinear coupling can sometimes be detrimental, but it can also be beneficial if properly designed into the system.

Owens, Benjamin A. M.; Mann, Brian P.

2012-02-01

114

Fabrication of a vibration-driven electromagnetic energy harvester with integrated NdFeB\\/Ta multilayered micro-magnets  

Microsoft Academic Search

This paper describes the fabrication of MEMS-based electromagnetic energy harvesters for scavenging energy from the ambient vibration. The novel energy harvester is fabricated by bonding a vibrator with embedded micro-magnets and a stator with integrated microcoils. The micro-magnets are formed by using sputtering deposition of NdFeB\\/Ta multilayered magnetic films with a thickness of 10 µm and silicon molding techniques. High-aspect-ratio

Yonggang Jiang; Shingo Masaoka; Takayuki Fujita; Minoru Uehara; Tomohiko Toyonaga; Kouhei Fujii; Kohei Higuchi; Kazusuke Maenaka

2011-01-01

115

Vibration energy harvesting using piezoelectric unimorph cantilevers with unequal piezoelectric and nonpiezoelectric lengths  

PubMed Central

We have examined a piezoelectric unimorph cantilever (PUC) with unequal piezoelectric and nonpiezoelectric lengths for vibration energy harvesting theoretically by extending the analysis of a PUC with equal piezoelectric and nonpiezoelectric lengths. The theoretical approach was validated by experiments. A case study showed that for a fixed vibration frequency, the maximum open-circuit induced voltage which was important for charge storage for later use occurred with a PUC that had a nonpiezoelectric-to-piezoelectric length ratio greater than unity, whereas the maximum power when the PUC was connected to a resistor for immediate power consumption occurred at a unity nonpiezoelectric-to-piezoelectric length ratio.

Gao, Xiaotong; Shih, Wei-Heng; Shih, Wan Y.

2010-01-01

116

Modeling and analysis of a micromachined piezoelectric energy harvester stimulated by ambient random vibrations  

NASA Astrophysics Data System (ADS)

Piezoelectric energy microgenerators are devices that continuously generate electricity when they are subjected to varying mechanical strain due to vibrations. They can generate electrical power up to 100 ?W which can be used to drive various sensing and actuating MEMS devices. Today, piezoelectric energy harvesters are considered autonomous and reliable energy sources to actuate low power microdevices such as wireless sensor networks, indoor-outdoor monitoring, facility management and biomedical applications. The advantages of piezoelectric energy harvesters including high power density, moderate output power and CMOS compatible fabrication in particular with aluminum nitride (AlN) have fuelled and motivated researchers to develop MEMS based energy harvesters. Recently, the use of AlN as a piezoelectric material has increased fabrication compatibility, enabling the realization of smart integrated systems on chip which include sensors, actuators and energy storage. Piezoelectric MEMS energy microgenerator is used to capture and transform the available ambient mechanical vibrations into usable electric energy via resonant coupling in the thin film piezoelectric material. Analysis and modeling of piezoelectric energy generators are very important aspects for improved performance. Aluminum nitride as the piezoelectric material is sandwiched between two electrodes. The device design includes a silicon cantilever on which the AlN film is deposited and which features a seismic mass at the end of the cantilever. Beam theory and lumped modeling with circuit elements are applied for modeling and analysis of the device operation at various acceleration values. The model shows good agreement with the experimental findings, thus giving confidence in the model.

Alamin Dow, Ali B.; Al-Rubaye, Hasan A.; Koo, David; Schneider, Michael; Bittner, Achim; Schmid, Ulrich; Kherani, Nazir P.

2011-05-01

117

Fully integrated micro electromagnetic vibration energy harvesters with micro-patterning of bonded magnets  

Microsoft Academic Search

This paper presents the fabrication and characterization of a novel fully integrated micro electromagnetic vibration energy harvester using micro-patterning of bonded magnets. The magnetic material utilized is a polymer composite, consisting of a commercially available NdFeB powder dispersed in epoxy resin to a weight loading percentage of 90%. The prototype is fabricated using UV-LIGA technology and microelectroplating technology. The whole

K. Tao; G. Ding; P. Wang; Z. Yang; Y. Wang

2012-01-01

118

Improved design of linear electromagnetic transducers for large-scale vibration energy harvesting  

Microsoft Academic Search

This paper presents the design and optimization of tubular Linear Electromagnetic Transducers (LETs) with applications to large-scale vibration energy harvesting, such as from vehicle suspensions, tall buildings or long bridges. Four types of LETs are considered and compared, namely, single-layer configuration using axial magnets, double-layer configuration using axial magnets, single-layer configuration using both axial and radial magnets, double-layer configuration using

Xiudong Tang; Lei Zuo; Teng Lin; Peisheng Zhang

2011-01-01

119

Enhancement of piezoelectric energy harvesting with multi-stable nonlinear vibrations  

NASA Astrophysics Data System (ADS)

The need for long-term solutions to power various wireless sensor systems has been driving the research in the area of energy harvesting for the past decade. The present paper brings forth an investigation into the realm of piezoelectric energy harvesting (PEH) using nonlinear vibrations. A piezoelectric cantilever beam with a magnetic tip mass interacting with additional magnets around it forms a multi-stable nonlinear PEH configuration. The study indicates that the multistable configuration provides a widened bandwidth as compared to the conventional linear PEH devices and an increased voltage output as compared to many other PEH devices. An experimental parametric study is conducted to arrive at an optimal configuration for the performance enhancement of the harvester along with a glimpse into the enhanced magnetostatic interactions equations and various possible magnetic nonlinear configurations for the given conditions.

Avvari, Panduranga Vittal; Tang, Lihua; Yang, Yaowen; Soh, Chee Kiong

2013-04-01

120

Artificial piezoelectric grass for energy harvesting from turbulence-induced vibration  

NASA Astrophysics Data System (ADS)

The primary objective of this research is to develop a deploy-and-forget energy harvesting device for use in low-velocity, highly turbulent fluid flow environments i.e. streams or ventilation systems. The work presented here focuses on a novel, lightweight, highly robust, energy harvester design referred to as piezoelectric grass. This biologically inspired design consists of an array of cantilevers, each constructed with piezoelectric material. When exposed to proper turbulent flow conditions, these cantilevers experience vigorous vibrations. Preliminary results have shown that a small array of piezoelectric grass was able to produce up to 1.0 mW per cantilever in high-intensity turbulent flow having a mean velocity of 11.5 m s-1. According to the literature, this is among the highest output achieved using similar harvesting methods. A distributed parameter model for energy harvesting from turbulence-induced vibration will be introduced and experimentally validated. This model is generalized for the case of a single cantilever in turbulent cross-flow. Two high-sensitivity pressure probes were needed to perform spectral measurements within various turbulent flows. The design and performance of these probes along with calibration and measurement techniques will be discussed.

Hobeck, J. D.; Inman, D. J.

2012-10-01

121

Electromagnetic Energy Harvesting Circuit With Feedforward and Feedback DC–DC PWM Boost Converter for Vibration Power Generator System  

Microsoft Academic Search

This paper presents an integrated vibration power generator system. The system consists of a mini electromagnetic vibration power generator and a highly efficient energy harvesting circuit implemented on a minute printed circuit board and a 0.35-mum CMOS integrated chip. By introducing a feedback control into the dc-dc pulsewidth modulation (PWM) boost converter with feedforward control, the energy harvesting circuit can

Xinping Cao; Wen-Jen Chiang; Ya-Chin King; Yi-Kuen Lee

2007-01-01

122

Micropower energy harvesting  

Microsoft Academic Search

More than a decade of research in the field of thermal, motion, vibration and electromagnetic radiation energy harvesting has yielded increasing power output and smaller embodiments. Power management circuits for rectification and DC–DC conversion are becoming able to efficiently convert the power from these energy harvesters. This paper summarizes recent energy harvesting results and their power management circuits.

R. J. M. Vullers; R. van Schaijk; I. Doms; C. Van Hoof; R. Mertens

2009-01-01

123

Energy harvesting of radio frequency and vibration energy to enable wireless sensor monitoring of civil infrastructure  

NASA Astrophysics Data System (ADS)

To power distributed wireless sensor networks on bridges, traditional power cables or battery replacement are excessively expensive or infeasible. This project develops two power harvesting technologies. First, a novel parametric frequency-increased generator (PFIG) is developed. The fabricated PFIG harvests the non-periodic and unprecedentedly low frequency (DC to 30 Hz) and low acceleration (0.55-9.8 m/s2) mechanical energy available on bridges with an average power > 2 ?W. Prototype power conversion and storage electronics were designed and the harvester system was used to charge a capacitor from arbitrary bridge-like vibrations. Second, an RF scavenger operating at medium and shortwave frequencies has been designed and tested. Power scavenging at MHz frequencies allows for lower antenna directivities, reducing sensitivity to antenna positioning. Furthermore, ambient RF signals at these frequencies have higher power levels away from cities and residential areas compared to the UHF and SHF bands utilized for cellular communication systems. An RF power scavenger operating at 1 MHz along with power management and storage circuitry has been demonstrated. It powers a LED at a distance of 10 km from AM radio stations.

Galchev, Tzeno; McCullagh, James; Peterson, Rebecca L.; Najafi, Khalil; Mortazawi, Amir

2011-03-01

124

Nonlinear Energy Harvesting  

Microsoft Academic Search

Ambient energy harvesting has been in recent years the recurring object of a number of research efforts aimed at providing an autonomous solution to the powering of small-scale electronic mobile devices. Among the different solutions, vibration energy harvesting has played a major role due to the almost universal presence of mechanical vibrations. Here we propose a new method based on

F. Cottone; H. Vocca; L. Gammaitoni

2009-01-01

125

Vibration energy harvesting based on integrated piezoelectric components operating in different modes.  

PubMed

To increase the vibration energy-harvesting capability of the piezoelectric generator based on a cantilever beam, we have proposed a piezoelectric generator that not only uses the strain change of piezoelectric components bonded on a cantilever beam, but also employs the weights at the tip of the cantilever beam to hit piezoelectric components located on the 2 sides of weights. A prototype of the piezoelectric generator has been fabricated and its characteristics have been measured and analyzed. The experimental results show that the piezoelectric components operating in the hit mode can substantially enhance the energy harvesting of the piezoelectric generator on a cantilever beam. Two methods are used and compared in the management of rectified output voltages from different groups of piezoelectric components. In one of them, the DC voltages from rectifiers are connected in series, and then the total DC voltage is applied to a capacitor. In another connection, the DC voltage from each group is applied to different capacitors. It is found that 22.3% of the harvested energy is wasted due to the series connection. The total output electric energy of our piezoelectric generator at nonresonance could be up to 43 nJ for one vibration excitation applied by spring, with initial vibration amplitude (0-p) of 18 mm and frequency of 18.5 Hz, when the rectified voltages from different groups of piezoelectric components are connected to their individual capacitors. In addition, the motion and impact of the weights at the tip of the cantilever beam are theoretically analyzed, which well explains the experimental phenomena and suggests the measures to improve the generator. PMID:20178904

Hu, Junhui; Jong, Januar; Zhao, Chunsheng

2010-01-01

126

Ferroelectric dipole electrets for output power enhancement in electrostatic vibration energy harvesters  

NASA Astrophysics Data System (ADS)

We propose a ferroelectric dipole electret composed of polarized lead zirconate titanate. Deep insight into the physics behind the parallel plate capacitor theoretically predicts that we can extract large electric field near the surface of the ferroelectric dipole electret by increasing its surface charge density and thickness. Experiment for ferroelectric dipole electret shows good agreement with the theory. The maximum output power density of electrostatic vibration energy harvesters using the ferroelectric dipole electret was 78 ?W/cm3, a three-fold increase over a conventional polymer electret. Our results will pave the way for use of ferroelectrics as electrets.

Asanuma, Haruhiko; Oguchi, Hiroyuki; Hara, Motoaki; Yoshida, Ryo; Kuwano, Hiroki

2013-10-01

127

H2 optimization of electricity-generating tuned mass dampers for simultaneous vibration control and energy harvesting  

NASA Astrophysics Data System (ADS)

The classic tuned mass damper (TMD) is a passive vibration control device composed of an auxiliary mass connected to a vibrating object with a spring and an energy-dissipative element. When its parameters are optimized, it can reduce the vibration effectively. Recently, the authors proposed simultaneous vibration control and energy harvesting from tall buildings by replacing the energy-dissipative element of the TMD with electromagnetic transducers, which is called electricity-generating TMD. However, the electromagnetic transducers and the energy harvesting circuit, the modeling of which is an essentially a RL circuit, will introduce extra dynamics into the system, which has significant influence on the vibration mitigation performance. This paper investigates the influence, by optimizing the parameters. We found that the electricity-generating TMD can provide better vibration mitigation performance than the classic TMD and similar performance as the three-element TMD while harvesting the vibration energy at the same time. This paper utilizes the H2 criterions, which is to minimize the root-mean-square vibration under random excitation. The optimization method is presented in this paper, as well as the concise closed-form solution of the optimal parameters. A case study is also given to illustrate the effectiveness, robustness of the electricity-generating TMD and the sensitivity to the parameter changes.

Cui, Wen; Tang, Xiudong; Zuo, Lei

2013-04-01

128

Vibration energy harvesting using highly (001)-oriented Pb(Zr,Ti)O3 thin film  

NASA Astrophysics Data System (ADS)

Energy conversion from mechanical vibration into electric power was investigated using the piezoelectric Pb(Zr,Ti)O3 lead zirconate titanate (PZT) thin film with highly (001)-orientation. The piezoelectric d31 constant was found to be as large as -150 pC/N. The generated electric voltage under vibration acceleration of 45 m/s2 at 2450 Hz for the PZT/Si cantilever exceeded 2 V and the operation of light emitting diode lighting was demonstrated. The average output power of 100 ?W was obtained at the impedance-matched load resistance of 2.2 k?. The generated power density of 50 ?W/mm3 was much larger than that of conventional piezoelectric harvesters.

Harigai, Takakiyo; Adachi, Hideaki; Fujii, Eiji

2010-05-01

129

Feasibility study of a 3D vibration-driven electromagnetic MEMS energy harvester with multiple vibration modes  

NASA Astrophysics Data System (ADS)

A novel electromagnetic energy harvester (EH) with multiple vibration modes has been developed and characterized using three-dimensional (3D) excitation at different frequencies. The device consists of a movable circular-mass patterned with three sets of double-layer aluminum (Al) coils, a circular-ring system incorporating a magnet and a supporting beam. The 3D dynamic behavior and performance analysis of the device shows that the first vibration mode of 1285 Hz is an out-of-plane motion, while the second and third modes of 1470 and 1550 Hz, respectively, are in-plane at angles of 60° (240°) and 150° (330°) to the horizontal (x-) axis. For an excitation acceleration of 1 g, the maximum power density achieved are 0.444, 0.242 and 0.125 µW cm-3 at vibration modes of I, II and III, respectively. The experimental results are in good agreement with the simulation and indicate a good potential in the development of a 3D EH device.

Liu, Huicong; Soon, Bo Woon; Wang, Nan; Tay, C. J.; Quan, Chenggen; Lee, Chengkuo

2012-12-01

130

Fabrication of a vibration-driven electromagnetic energy harvester with integrated NdFeB/Ta multilayered micro-magnets  

NASA Astrophysics Data System (ADS)

This paper describes the fabrication of MEMS-based electromagnetic energy harvesters for scavenging energy from the ambient vibration. The novel energy harvester is fabricated by bonding a vibrator with embedded micro-magnets and a stator with integrated microcoils. The micro-magnets are formed by using sputtering deposition of NdFeB/Ta multilayered magnetic films with a thickness of 10 µm and silicon molding techniques. High-aspect-ratio silicon micro-springs are fabricated using deep reactive ion etching to achieve large vibration amplitude. The microcoils fabricated by electroplating processes are serially connected for multiplication of the output voltages from individual magnet-coil units. The energy harvester is successfully fabricated and wire-bonded for characterization. The maximum voltage output of the energy harvester at 115 Hz is approximately 2 mV, which corresponds to a power density of 1.2 nW cm-3. The performance of the energy harvester could be greatly improved by protecting the micro-magnets from oxidation and decreasing the spacing between the vibrator layer and the stator layer.

Jiang, Yonggang; Masaoka, Shingo; Fujita, Takayuki; Uehara, Minoru; Toyonaga, Tomohiko; Fujii, Kouhei; Higuchi, Kohei; Maenaka, Kazusuke

2011-09-01

131

Self-powered autonomous wireless sensor node using vibration energy harvesting  

NASA Astrophysics Data System (ADS)

This paper reports the development and implementation of an energy aware autonomous wireless condition monitoring sensor system (ACMS) powered by ambient vibrations. An electromagnetic (EM) generator has been designed to harvest sufficient energy to power a radio-frequency (RF) linked accelerometer-based sensor system. The ACMS is energy aware and will adjust the measurement/transmit duty cycle according to the available energy; this is typically every 3 s at 0.6 m s-2rms acceleration and can be as low as 0.2 m s-2rms with a duty cycle around 12 min. The EM generator has a volume of only 150 mm3 producing an average power of 58 µW at 0.6 m s-2rms acceleration at a frequency of 52 Hz. In addition, a voltage multiplier circuit is shown to increase the electrical damping compared to a purely resistive load; this allows for an average power of 120 µW to be generated at 1.7 m s-2rms acceleration. The ACMS has been successfully demonstrated on an industrial air compressor and an office air conditioning unit, continuously monitoring vibration levels and thereby simulating a typical condition monitoring application.

Torah, R.; Glynne-Jones, P.; Tudor, M.; O'Donnell, T.; Roy, S.; Beeby, S.

2008-12-01

132

The design, fabrication and evaluation of a MEMS PZT cantilever with an integrated Si proof mass for vibration energy harvesting  

Microsoft Academic Search

A microelectromechanical system (MEMS) piezoelectric energy harvesting device, a unimorph PZT cantilever with an integrated Si proof mass, was designed for low vibration frequency and high vibration amplitude environment. Pt\\/PZT\\/Pt\\/Ti\\/SiO2 multilayered films were deposited on a Si substrate and then the cantilever was patterned and released by inductively coupled plasma reactive ion etching. The fabricated device, with a beam dimension

Dongna Shen; Jung-Hyun Park; Jyoti Ajitsaria; Song-Yul Choe; Howard C. Wikle III; Dong-Joo Kim

2008-01-01

133

Improved design of linear electromagnetic transducers for large-scale vibration energy harvesting  

NASA Astrophysics Data System (ADS)

This paper presents the design and optimization of tubular Linear Electromagnetic Transducers (LETs) with applications to large-scale vibration energy harvesting, such as from vehicle suspensions, tall buildings or long bridges. Four types of LETs are considered and compared, namely, single-layer configuration using axial magnets, double-layer configuration using axial magnets, single-layer configuration using both axial and radial magnets, double-layer configuration using both axial and radial magnets. In order to optimize the LETs, the parameters investigated in this paper include the thickness of the magnets in axial direction and the thickness of the coils in the radial direction. Finite element method is used to analyze the axisymmetric two-dimensional magnetic fields. Both magnetic flux densities Br [T] in the radial direction and power density [W/m3] are calculated. It is found that the parameter optimization can increase the power density of LETs to 2.7 times compared with the initial design [Zuo et al, Smart Materials and Structures, v19 n4, 2010], and the double-layer configuration with both radial and axial magnets can improve the power density to 4.7 times, approaching to the energy dissipation rate of traditional oil dampers. As a case study, we investigate its application to energy-harvesting shock absorbers. For a reasonable retrofit size, the LETs with double-layer configuration and both axial and radial NdFeB magnets can provide a damping coefficient of 1138 N·s/m while harvesting 35.5 W power on the external electric load at 0.25 m/s suspension velocity. If the LET is shorten circuit, it can dissipate energy at the rate of 142.0 W, providing of a damping coefficient of 2276 N·s/m. Practical consideration of number of coil phases is also discussed.

Tang, Xiudong; Zuo, Lei; Lin, Teng; Zhang, Peisheng

2011-03-01

134

Design, fabrication and characterization of a micromachined piezoelectric energy harvester excited by ambient vibrations  

NASA Astrophysics Data System (ADS)

This research work presents the design, fabrication and characterization of micromachined piezoelectric energy harvester stimulated by ambient random vibrations utilizing AlN as a piezoelectric material. The device design consists of a silicon cantilever beam on which AlN is sandwiched between two electrodes and a silicon seismic mass at the end of the cantilever beam. The generated electric power of the devices was experimentally measured at various acceleration levels. A maximum power of 34 ?W was obtained at an acceleration value of 2g for the device which measures 5.6 x 5.6 mm2. Various unpackaged devices were tested and assessed in terms of the generated power and resonant frequency at various acceleration values.

Alamin Dow, Ali B.; Bittner, Achim; Schmid, Ulrich; Kherani, Nazir P.

2013-05-01

135

Design, simulation, fabrication and characterization of a micro electromagnetic vibration energy harvester with sandwiched structure and air channel  

Microsoft Academic Search

This paper presents the design, simulation, fabrication and characterization of a novel electromagnetic vibration energy harvester with sandwiched structure and air channel. It mainly consists of a top coil, a bottom coil, an NdFeB permanent magnet and a nickel planar spring integrated with silicon frame. The prototype is fabricated mainly using silicon micromachining and microelectroplating techniques. The tested natural frequency

Peihong Wang; Huiting Liu; Xuhan Dai; Zhuoqing Yang; Zhongzhu Wang; Xiaolin Zhao

136

Modeling and design of an electromagnetic vibration energy harvester and its dedicated energy extraction circuit  

Microsoft Academic Search

This work investigates the design of an electromagnetic generator including its energy extraction and conditioning circuit. The normalized model of an electromagnetic generator points out three dimensionless parameters, characteristic of the generator. The power harvested with the SMFE (Synchronized Magnetic Flux Extraction) circuit is theoretically calculated and compared to the power extracted with a conventional approach. Optimal parameters orders of

Emmanuelle Arroyo; Adrien Badel; Fabien Formosa

2012-01-01

137

Optimal design of a vibration-based energy harvester using magnetostrictive material (MsM)  

NASA Astrophysics Data System (ADS)

In this study, an optimal vibration-based energy harvesting system using magnetostrictive material (MsM) was designed and tested to enable the powering of a wireless sensor. In particular, the conversion efficiency, converting from magnetic to electric energy, is approximately modeled from the magnetic field induced by the beam vibration. A number of factors that affect the output power such as the number of MsM layers, coil design and load matching are analyzed and explored in the design optimization. From the measurements, the open-circuit voltage can reach 1.5 V when the MsM cantilever beam operates at the second natural frequency 324 Hz. The AC output power is 970 µW, giving a power density of 279 µW cm - 3. The attempt to use electrical reactive components (either inductors or capacitors) to resonate the system at any frequency has also been analyzed and tested experimentally. The results showed that this approach is not feasible to optimize the power. Since the MsM device has low output voltage characteristics, a full-wave quadrupler has been designed to boost the rectified output voltage. To deliver the maximum output power to the load, a complex conjugate impedance matching between the load and the MsM device is implemented using a discontinuous conduction mode (DCM) buck-boost converter. The DC output power after the voltage quadrupler reaches 705 µW and the corresponding power density is 202 µW cm - 3. The output power delivered to a lithium rechargeable battery is around 630 µW, independent of the load resistance.

Hu, J.; Xu, F.; Huang, A. Q.; Yuan, F. G.

2011-01-01

138

IPP: Piezoelectric Energy Harvesters  

NASA Video Gallery

Piezoelectric devices can convert mechanical energy -- like ambient vibrations -- into electrical energy that can power small devices.A group of NASA engineers is developing a way to amplify the forces being put into piezoelectric devices so we can harvest more energy from them.

Robert Allen

2010-12-15

139

A study of several vortex-induced vibration techniques for piezoelectric wind energy harvesting  

NASA Astrophysics Data System (ADS)

This paper discusses a preliminary study on harnessing energy from piezoelectric transducers by using bluff body and vortex-induced vibration phenomena. Structures like bridges and buildings tend to deform and crack due to chaotic fluid-structure interactions. The rapid variation of pressure and velocity can be tapped and used to power structural health monitoring systems. The proposed device is a miniature, scalable wind harvesting device. The configuration consists of a bluff body with a flexible piezoelectric cantilever attached to the trailing edge. Tests are run for different characteristic dimensions or shapes for the bluff body and optimized for maximum power over a wide range of flow velocities. The main motive here is to seek a higher synchronized region of frequencies for the oscillation amplitudes. The multi-physics software package COMSOL is used to vary the design parameters to optimize the configuration and to identify the significant parameters in the design. The simulation results obtained show a wider lock-in bandwidth and higher average power for the cylindrical bluff body compared to the other two bluff body shapes investigated, the greatest average power being 0.35mW at a Reynolds number of 900, beam length of 0.04m, and bluff body diameter of 0.02m.

Sivadas, Vishak; Wickenheiser, Adam M.

2011-03-01

140

Design Feasibility of a Vortex Induced Vibration Based Hydro-Kinetic Energy Harvesting System  

Microsoft Academic Search

The vortex induced vibration (VIV) based power generating system discussed in this paper is a new concept in power generation from fluid flows in oceans, rivers and streams. The possibility of harnessing energy from the vibrations incurred in a bluff body due to the phenomenon known as VIV, in which motion is induced on a body facing an external flow

Varun Lobo; Nyuykighan Mainsah; Arindam Banerjee; Jonathan W. Kimball

2011-01-01

141

A MEMS-Based Piezoelectric Power Generator for Low Frequency Vibration Energy Harvesting  

Microsoft Academic Search

A novel power generator has been achieved to convert vibration to electrical energy via the piezoelectric effect. The generator obtained by micro fabrication process mainly consists of silicon based frame and composite cantilever. The prototype tested at resonant vibration generates 1.15 muW of effective power to a 20.4-kOmega resistance load. The potential of this work is to offer miniaturization solutions

Hua-Bin Fang; Jing-Quan Liu; Zheng-Yi Xu; Lu Dong; Di Chen; Bing-Chu Cai; Yue Liu

2006-01-01

142

A piezoelectric energy harvester with increased bandwidth based on beam flexural vibrations in perpendicular directions.  

PubMed

We propose a new structure for piezoelectric energy harvesters. It consists of an elastic beam with two pairs of piezoelectric films operating with the fundamental flexural modes in perpendicular directions. A one-dimensional model is developed and used to analyze the proposed structure. The output power density is calculated and examined. Results show that, with simultaneous flexural motions in two perpendicular directions, the output power has two peaks close to each other resulting from the two fundamental flexural resonances. The distance between the two peaks can be adjusted through design to make the two peaks merge into one wide peak. Hence, the frequency bandwidth through which energy can be harvested is roughly doubled when compared with conventional beam bimorph energy harvesters operating with flexural motion in one direction and one resonance only. PMID:24081271

Li, Peng; Jin, Feng; Yang, Jiashi

2013-10-01

143

Development of energy harvester system for avionics  

NASA Astrophysics Data System (ADS)

This paper deals with an energy harvesting system for avionics; it is an energy source for a unit which is used for wireless monitoring or autonomous control of a small aircraft engine. This paper is focused on development process of energy harvesting system from mechanical vibrations in the engine area. The used energy harvesting system consists of an electro-magnetic energy harvester, power management and energy storage element. The energy harvesting system with commercial power management circuits have to be tested and verified measured results are used for an optimal redesign of the electro-magnetic harvester. This developmental step is necessary for the development of the optimal vibration energy harvesting system.

Hadas, Z.; Vetiska, V.; Ancik, Z.; Ondrusek, C.; Singule, V.

2013-05-01

144

An energy harvesting system using the wind-induced vibration of a stay cable for powering a wireless sensor node  

NASA Astrophysics Data System (ADS)

This paper proposes an electromagnetic energy harvesting system, which utilizes the wind-induced vibration of a stay cable, and investigates its feasibility for powering a wireless sensor node on the cable through numerical simulations as well as experimental tests. To this end, the ambient acceleration responses of a stay cable installed in an in-service cable-stayed bridge are measured, and then they are used as input excitations in cases of both numerical simulations and experimental tests to evaluate the performance of the proposed energy harvesting system. The results of the feasibility test demonstrate that the proposed system generates sufficient electricity for operation of a wireless sensor node attached on the cable under the moderate wind conditions.

Jung, Hyung-Jo; Kim, In-Ho; Jang, Seon-Jun

2011-07-01

145

A New Design for Vibration-Based Electromagnetic Energy Harvesting Systems Using Coil Inductance of Microgenerator  

Microsoft Academic Search

In this paper, a new design methodology for low- voltage electromagnetic energy harvesting systems consisting of a microgenerator and power processing circuit is introduced. In the first section of this paper, a simple topology for a resonance-based electromagnetic generator is presented. The microgenerator is capable of producing a voltage of a few hundred millivolts. Since traditional two-stage power conversion schemes

Rohan Dayal; Suman Dwari; Leila Parsa

2011-01-01

146

Flat and robust out-of-plane vibrational electret energy harvester  

NASA Astrophysics Data System (ADS)

This paper reports the design, fabrication and testing of two types of out-of-plane electret energy harvesters. Copper plates and flexible printed circuit board (FPCB) were used to fabricate the harvesters for a lower fabrication cost and a more robust structure. Several dielectric materials were investigated and SiO2/Si3N4 double layers were found to have better charge stability. The measured surface potential and charge density of the SiO2/Si3N4 electret were -400 V and 13.5 mC m-2, respectively. It was found that charge stability could be improved by multiple corona charging cycles. Using SiO2/Si3N4 as the electret material, the measured power output was 20.7 µW at 110 Hz for 2 G acceleration with a 50 M? load for the copper harvester and 0.82 µW at 172 Hz for 2 G acceleration with a 30 M? load for the FPCB harvester.

Chiu, Yi; Lee, Yen-Chieh

2013-01-01

147

An autoparametric energy harvester  

NASA Astrophysics Data System (ADS)

This paper presents a numerical study of an autoparametric system composed of two elements: a pendulum and an excited nonlinear oscillator. Owing to an inertial coupling between the two elements, different types of motion are possible, from periodic to chaotic. This study examines a linear induction of an energy harvester depending on the pendulum motion. The harvester consists of a cylindrical permanent magnet mounted on a rotor and of four windings fixed to the housing as a stator. When the pendulum is rotating or swinging, the converter is generating energy due to magnetic induction. In this paper, a method utilizing parametrical resonance for harvesting energy from low frequency vibrations is studied. The authors compare energy induced by different types of pendulum motion: swinging, rotation and chaotic dynamics. Additionally, voltage values for different parameters of excitation are estimated.

Kecik, K.; Borowiec, M.

2013-09-01

148

A General Analytical Tool for the Design of Vibration Energy Harvesters (VEHs) Based on the Mechanical Impedance Concept  

Microsoft Academic Search

This paper reports on a new approach for the anal- ysis and design of vibration-to-electricity converters (vibration en- ergy harvesters (VEHs)) operating in the mode of strong electro- mechanical coupling. The underlying concept is that the mechan- ical impedance is defined for a nonlinear electromechanical trans- ducer on the basis of an equivalence between electrical and me- chanical systems. This

Dimitri Galayko; Philippe Basset

2011-01-01

149

Enhancement of piezoelectric vibration energy harvester output power level for powering of wireless sensor node in large rotary machine diagnostic system  

Microsoft Academic Search

The paper presents results of experimental and theoretical studies on small-size piezoelectric generators, in which energy of machine mechanical vibrations is harvested and converted to electric energy. These piezoelectric generators were proposed, as an alternative to a battery-based solution, for powering of sensor nodes in condition monitoring systems of large rotary machines such as turbogenerators in power plants. Initial studies

B. Pekoslawski; Piotr Pietrzak; Maciej Makowski; Andrzej Napieralski

2009-01-01

150

Wideband excitation of an electrostatic vibration energy harvester with power-extracting end-stops  

NASA Astrophysics Data System (ADS)

An electrostatic energy harvester with two-stage transduction is investigated for enhancement of bandwidth and dynamic range. The harvester includes a primary proof mass with two main transducers and end-stops for the proof mass functioning as secondary transducers. In the small acceleration regime, the power is primarily obtained from the main transducers. In the high acceleration regime, the mass impacts the end-stops and actuates the secondary transducers, generating additional output power. The device is designed and fabricated using the SOIMUMPs process and has a total active area of 4 × 5 mm2. Under wideband acceleration at high levels, the experimental results show that the total output power increases to about twice the output power of the main transducers, while the 3 dB-bandwidth is enlarged by a factor of 6.7 compared to the linear-response bandwidth at low levels. In comparison with a reference device made with the same die dimensions, the two-stage device improves output power instead of saturating when the maximum mass displacements of both devices reach the same limit. Measurement of output power demonstrates that the device with the transducing end-stops give an efficiency of 23.6%, while this value is 14.1% for the reference device with the conventional end-stops, at an acceleration spectral density of Sa = 19.2 × 10?3 g2 Hz?1. The efficiency is improved about by 9.5% in the impact regime.

Phu Le, Cuong; Halvorsen, Einar; Søråsen, Oddvar; Yeatman, Eric M.

2013-07-01

151

Noise powered nonlinear energy harvesting  

NASA Astrophysics Data System (ADS)

The powering of small-scale electronic mobile devices has been in recent years the subject of a great number of research efforts aimed primarily at finding an alternative solution to standard batteries. The harvesting of kinetic energy present in the form of random vibrations (from non-equilibrium thermal noise up to machine vibrations) is an interesting option due to the almost universal presence of some kind of motion. Present working solutions for vibration energy harvesting are based on oscillating mechanical elements that convert kinetic energy via capacitive, inductive or piezoelectric methods. These oscillators are usually designed to be resonantly tuned to the ambient dominant frequency. However, in most cases the ambient random vibrations have their energy distributed over a wide spectrum of frequencies, especially at low frequency, and frequency tuning is not always possible due to geometrical/dynamical constraints. We present a new approach to the powering of small autonomous sensors based on vibration energy harvesting by the exploitation of nonlinear stochastic dynamics. Such a method is shown to outperform standard linear approaches based on the use of resonant oscillators and to overcome some of the most severe limitations of present strategies, like narrow bandwidth, need for continuous frequency tuning and low power efficiency. We demonstrate the superior performances of this method by applying it to piezoelectric energy harvesting from ambient vibration.

Gammaitoni, Luca; Neri, Igor; Vocca, Helios

2011-04-01

152

Design and fabrication of a PZT cantilever for low frequency vibration energy harvesting.  

PubMed

In this study, a PZT cantilever with a Si proof mass is designed and fabricated for a low frequency energy harvesting application. A mathematical model of a multi-layer composite beam was derived and applied in a parametric analysis of the piezoelectric cantilever. Finally, the dimensions of the cantilever were determined for the resonant frequency of the cantilever. Our cantilever design was based on MATLAB and ANSYS simulations. For this simulation, the proof mass volumes were varied from 0 to 0.5 mm3 and resonant frequencies were calculated from 833.5 Hz to 125.5 Hz, respectively. Based on simulation, we fabricated a device with beam dimensions of about 4.10 mm x 0.48 mm x 0.012 mm, and an integrated Si proof mass with dimensions of about 0.481 mm x 0.48 mm x 0.45 mm. The resonant frequency, maximum peak voltage, and highest average power of the cantilever device were 224.8 Hz, 4.8 mV, and 2.24 nW, respectively. PMID:22121746

Kim, Moonkeun; Hwang, Beomseok; Min, Nam Ki; Jeong, Jaehwa; Kwon, Kwang-Ho; Park, Kang-Bak

2011-07-01

153

Simulation and experiment validation of simultaneous vibration control and energy harvesting from buildings using Tuned Mass Dampers  

Microsoft Academic Search

For the protection of the structure safety and occupant comfort, the vibrations of the tall buildings are serious concerns for both engineers and architects. In order to mitigate the vibration, different approaches have been proposed, among which Tuned Mass Dampers (TMDs) are one of the most preferable and have been widely used in practice. Instead of dissipating the vibration energy

Xiudong Tang; Lei Zuo

2011-01-01

154

A MEMS-based piezoelectric power generator array for vibration energy harvesting  

Microsoft Academic Search

Piezoelectric power generator made by microelectromechanical system (MEMS) technology can scavenge power from low-level ambient vibration sources. The developed MEMS power generators are featured with fixed\\/narrow operation frequency and power output in microwatt level, whereas, the frequency of ambient vibration is floating in some range, and power output is insufficient. In this paper, a power generator array based on thick-film

Jing-Quan Liu; Hua-Bin Fang; Zheng-Yi Xu; Xin-Hui Mao; Xiu-Cheng Shen; Di Chen; Hang Liao; Bing-Chu Cai

2008-01-01

155

TOPICAL REVIEW: Strategies for increasing the operating frequency range of vibration energy harvesters: a review  

NASA Astrophysics Data System (ADS)

This review presents possible strategies to increase the operational frequency range of vibration-based micro-generators. Most vibration-based micro-generators are spring-mass-damper systems which generate maximum power when the resonant frequency of the generator matches the frequency of the ambient vibration. Any difference between these two frequencies can result in a significant decrease in generated power. This is a fundamental limitation of resonant vibration generators which restricts their capability in real applications. Possible solutions include the periodic tuning of the resonant frequency of the generator so that it matches the frequency of the ambient vibration at all times or widening the bandwidth of the generator. Periodic tuning can be achieved using mechanical or electrical methods. Bandwidth widening can be achieved using a generator array, a mechanical stopper, nonlinear (e.g. magnetic) springs or bi-stable structures. Tuning methods can be classified into intermittent tuning (power is consumed periodically to tune the device) and continuous tuning (the tuning mechanism is continuously powered). This review presents a comprehensive review of the principles and operating strategies for increasing the operating frequency range of vibration-based micro-generators presented in the literature to date. The advantages and disadvantages of each strategy are evaluated and conclusions are drawn regarding the relevant merits of each approach.

Zhu, Dibin; Tudor, Michael J.; Beeby, Stephen P.

2010-02-01

156

Energy harvesting projects  

Microsoft Academic Search

This article examines how harvesting environmental energy in sensor networks changes the way an application developer views energy management, and discusses prototype devices. Then it proposes devices that combine energy harvesting and data acquisition. Then it explores novel approaches for optimizing the power extracted using piezoelectric materials. The final one explores kinetic and thermal energy harvesting from human users' activities.

A. D. Joseph

2005-01-01

157

Highly scalable and sensitive broadband 1Hz ? 1kHz vibrated energy harvester with novel self-alternation magnetic-flux and 3D coils  

Microsoft Academic Search

For the first time, we report a reproducible, highly scalable, and highly sensitive broadband 1Hz~1kHz vibrated energy harvester with innovated self-alternation magnetic-flux (SAMF) and 3D-coils designs. Record high sensitivity of 2~6 mV\\/coil at very wide frequency range of 1Hz ~ 1kHz than previous reports (~1 mV\\/coil), record small magnet volume of 132 mm 3 , and the very fast transient

Y. S. Lai; M. Q. Wei; H. C. Lin; Y. J. Cheng; Y. B. Lin; C. H. Ho

2011-01-01

158

Strength analysis of piezoceramic materials for structural considerations in energy harvesting for UAVs  

Microsoft Academic Search

Vibration energy harvesting has received considerable attention in the research community over the past decade. Typical vibration harvesting systems are designed to be added on to existing host structures and capture ambient vibration energy. An interesting application of vibration energy harvesting exists in unmanned aerial vehicles (UAVs), where a multifunctional approach, as opposed to the traditional method, is needed due

S. R. Anton; A. Erturk; D. J. Inman

2010-01-01

159

DSPs for energy harvesting sensors: applications and architectures  

Microsoft Academic Search

Energy harvesting from human or environmental sources shows promise as an alternative to battery power for embedded digital electronics. Digital signal processors that harvest power from ambient mechanical vibration are particularly promising for sensor networks.

Rajeevan Amirtharajah; Jamie Collier; Jeff Siebert; Bicky Zhou; Anantha Chandrakasan

2005-01-01

160

Optimization and AMS Modeling for Design of an Electrostatic Vibration Energy Harvester's Conditioning Circuit with an Auto-Adaptive Process to the External Vibration Changes  

Microsoft Academic Search

Electrostatic transducers for vibration energy scavenging have been an object\\u000ato numerous studies, but are still facing major issues relating to their\\u000aconditioning circuit. One of the most popular ones uses a charge pump and a\\u000aflyback circuit based on a Buck DC-DC converter (Fig. 1). A commutation between\\u000athe energy accumulation in the charge pump and the recharge of

Dimitri Galayko; Philippe Basset; Ayyaz Mahmood Paracha

2008-01-01

161

PIEZOELECTRIC MICRO POWER GENERATOR FOR ENERGY HARVESTING  

Microsoft Academic Search

A thin film lead zirconate titanate Pb(Zr,Ti)O3 (PZT), power generating device is developed. It is designed to resonate at specific vibrational frequencies from an ambient, vibrational energy source, thereby creating electrical energy via the piezoelectric effect. The energy harvesting device uses the piezoelectric d33 mode and is fabricated with three mask steps. Our cantilever device was designed to have a

R. Sood; Y. B. Jeon; S. G. Kim

162

The physical acoustics of energy harvesting  

Microsoft Academic Search

Energy harvesting systems based on the transformation of acoustic vibrations into electrical energy are increasingly being used for niche applications due to the reduction in power consumption of modern day electronic systems. Typically these applications involve extracting energy at remote or isolated locations where local long term power is unavailable or inside sealed or rotating systems where cabling and electrical

Stewart Sherrit

2008-01-01

163

A tunable kinetic energy harvester with dynamic over range protection  

NASA Astrophysics Data System (ADS)

This paper describes the development and implementation of a self-powered control system that autonomously adapts the resonant frequency of an electromagnetic vibration-based energy harvester to ambient vibration frequency. The tuning mechanism adjusts the harvester's spring stiffness by varying the axial tensile force between two permanent magnets. The system adjusts the resonant frequency of the harvester from 64 to 78 Hz, increasing the operational bandwidth of the harvester from 0.26 to 14 Hz, using a single structure. The same tuning principle is also applied to protect the harvester from over range acceleration which could cause physical damage to its structure. The closed loop control uses the phase difference between the harvester output signal and ambient vibration, measured by an accelerometer attached to the vibration source, to adjust the tuning mechanism.

Ayala-Garcia, I. N.; Zhu, D.; Tudor, M. J.; Beeby, S. P.

2010-11-01

164

Energy harvesting circuit for sensor system power supply  

NASA Astrophysics Data System (ADS)

The paper presents two example approaches to energy harvesting. Mechanical energy harvesting system is based on vibrational minigenerator. Basic relations of its analytical model are given in order to obtain an idea about the operating conditions. Electromagnetic harvesting system is based on tuned resonant nano-structure. Its concepts allows impedance matching in order to operate in given frequency range. The matching properties are verified by means of numerical finite element analysis. For power management of vibration energy harvesting system several circuit design concepts are presented together with simulation results and basic properties comparison.

Fiala, P.; Drexler, P.

2011-05-01

165

Self-timed circuits for energy harvesting AC power supplies  

Microsoft Academic Search

The recent explosion in capability of embedded and portable electronics has not been matched by battery technology. The slow growth of battery energy density has limited device lifetime and added weight and volume. Passive energy harvesting from vibration has potentially wide application in wearable and embedded sensors to complement or replace batteries. We propose increasing energy harvesting efficiency by eliminating

Jeff Siebert; Jamie Collier; Rajeevan Amirtharajah

2005-01-01

166

Energy harvesting from human motion: an evaluation of current nonlinear energy harvesting solutions  

NASA Astrophysics Data System (ADS)

The concept of harvesting electrical energy from ambient vibration sources has been a popular topic of research in recent years. Recently, the realisation that the majority of ambient vibration sources are often stochastic in nature has led to a large body of work which has focused on the response of energy harvesters to random excitations - most of which approximate environmental excitations as being Gaussian white noise. Of particular interest here are recent findings which demonstrate the advantages that Duffing-type nonlinearities can introduce into energy harvesters. The aim of this paper is to identify how well these results can be applied to that of a real energy harvesting scenario. More specifically, the response of an energy harvester to excitation via human motion is studied using digital simulations in conjunction with acceleration data obtained from a human participant. As well as assessing whether Duffing-type nonlinearities can have a beneficial impact on device performance this paper aims to investigate whether Gaussian white noise can indeed be used as a good approximation for this particular ambient vibration source.

Green, P. L.; Papatheou, E.; Sims, N. D.

2012-08-01

167

A resonant frequency tunable, extensional mode piezoelectric vibration harvesting mechanism  

NASA Astrophysics Data System (ADS)

Electrical power for distributed, wireless sensors may be harvested from vibrations in the ambient through the use of electromechanical transducers. To be most useful, the electromechanical transducer should maximize the harvested power by matching its resonant frequency to the strongest vibration amplitude in the source's vibration spectrum. This paper introduces a new frequency tunable mechanism wherein the deformation of the piezoelectric elements is primarily in-plane extension, and bending effects may be neglected. The extensional mode resonator (XMR) is formed by suspending a seismic mass with two piezoelectric sheets. The mechanism is made frequency tunable by an adjustable link that symmetrically pre-tensions both piezoelectric sheets. A prototype XMR has been built and tested that has demonstrated adjustable and repeatable resonant frequency variation from 80 to 235 Hz. The electrical power generated by the XMR is also insensitive to the driving frequency, when the resonant frequency is matched to the driving frequency.

Morris, Dylan J.; Youngsman, John M.; Anderson, Michael J.; Bahr, David F.

2008-12-01

168

On the efficiencies of piezoelectric energy harvesting circuits towards storage device voltages  

Microsoft Academic Search

Using piezoelectric elements to harvest energy from ambient vibrations has been of great interest over the past few years. Due to the relatively low power output of piezoelectric materials, energy storage devices are used to accumulate harvested energy for intermittent use. Piezoelectric energy harvesting circuits have two schemes: one-stage and two-stage energy harvesting. A one-stage energy harvesting scheme includes a

M. J. Guan; W. H. Liao

2007-01-01

169

A novel method for piezoelectric energy harvesting from keyboard  

NASA Astrophysics Data System (ADS)

This paper presents a novel method and apparatus for converting keystrokes to electrical energy using a resonant energy harvester, which can be coupled with keyboards. The state-of-the-art dome switch design is modified to excite the tip of the energy harvester beam. Piezoelectric transduction converts vibrations to electrical power. The energy harvester design is optimized to give highest voltage output under use conditions, and is fabricated. A close match is observed for the first natural frequency. When the piezoelectric energy harvester is excited at 7.62 Hz with tip excitation to emulate keyboard use, 16.95 ?W of power is generated.

Beker, Levent; Muhtaroglu, Ali; Külah, Haluk

2012-03-01

170

Magnetoelectric properties and magnetomechanical energy harvesting from stray vibration and electromagnetic wave by Pb(Mg1/3Nb2/3)O3-Pb(Zr,Ti)O3 single crystal/Ni cantilever  

NASA Astrophysics Data System (ADS)

Magnetoelectric (ME) rectangular unimorph cantilever beam structures of piezoelectric Pb(Mg1/3Nb2/3)O3-Pb(Zr,Ti)O3 (PMN-PZT) single crystal on magnetostrictive Ni plate was designed with <001> and <011>-cut crystallographic directions and investigated their ME response and mechanical vibration based energy harvesting behavior. Both magnetoelectric (ME) voltage coefficient (?ME) and mechanically harvested power output was found to be strongly dependent on the crystallographic cut directions of PMN-PZT single crystals. The maximum ?ME and power output of 7.28 V/cm Oe and 1.31 mW was observed for <011> PMN-PZT/i unimorph ME structure at resonance mode under 0.7 G acceleration. The <011> PMN-PZT single crystal showed that in-plane anisotropic behavior, i.e., d31 and d32 significantly affect to the magnitude of ?ME and harvested power output.

Kambale, Rahul C.; Yoon, Woon-Ha; Park, Dong-Soo; Choi, Jong-Jin; Ahn, Cheol-Woo; Kim, Jong-Woo; Hahn, Byung-Dong; Jeong, Dae-Yong; Chul Lee, Byung; Chung, Gwiy-Sang; Ryu, Jungho

2013-05-01

171

A Review of Power Harvesting from Vibration Using Piezoelectric Materials  

Microsoft Academic Search

The process of acquiring the energy surround- ing a system and converting it into usable electrical energy is termed power harvesting. In the last few years, there has been a surge of research in the area of power harvesting. This increase in research has been brought on by the mod- ern advances in wireless technology and low-power electron- ics such

Henry A. Sodano; Daniel J. Inman

2004-01-01

172

Disc-shaped IPMC for use in energy harvesting  

NASA Astrophysics Data System (ADS)

Conventionally, energy harvesting from IPMC is studied in the bender configuration. However, for energy harvesting from uncontrolled or multi-directional vibration, there is a need to produce 2-D and/or 3-D energy harvester. This paper discusses the use of IPMC for energy harvesting using disc-shaped IPMCs. Making disc imparts more flexibility to the sample and enables energy harvesting from all around the perimeter of the disc without increase in size. Disc-shaped IPMCs were prepared from Nafion granules using a hot press method. The manufactured discs are flexible and suitable for bending not only along the diameter but also side ways. The sample was vibrated along the diameter at 1Hz, 0.25 inch displacement using a TIRA shaker for the testing.

Tiwari, R.; Kim, K. J.

2009-03-01

173

Adaptive piezoelectric energy harvesting circuit for wireless remote power supply  

Microsoft Academic Search

This paper describes an approach to harvesting electrical energy from a mechanically excited piezoelectric element. A vibrating piezoelectric device differs from a typical electrical power source in that it has a capacitive rather than inductive source impedance, and may be driven by mechanical vibrations of varying amplitude. An analytical expression for the optimal power flow from a rectified piezoelectric device

Geffrey K. Ottman; Heath F. Hofmann; Archin C. Bhatt; George A. Lesieutre

2002-01-01

174

An experimentally validated bimorph cantilever model for piezoelectric energy harvesting from base excitations  

Microsoft Academic Search

Piezoelectric transduction has received great attention for vibration-to-electric energy conversion over the last five years. A typical piezoelectric energy harvester is a unimorph or a bimorph cantilever located on a vibrating host structure, to generate electrical energy from base excitations. Several authors have investigated modeling of cantilevered piezoelectric energy harvesters under base excitation. The existing mathematical modeling approaches range from

A. Erturk; D. J. Inman

2009-01-01

175

Development of enhanced piezoelectric energy harvester induced by human motion.  

PubMed

In this study, a high frequency piezoelectric energy harvester converted from the human low vibrated motion energy was newly developed. This hybrid energy harvester consists of the unimorph piezoelectric cantilever and a couple of permanent magnets. One magnet was attached at the end of cantilever, and the counterpart magnet was set at the end of the pendulum. The mechanical energy provided through the human walking motion, which is a typical ubiquitous presence of vibration, is converted to the electric energy via the piezoelectric cantilever vibration system. At first, we studied the energy convert mechanism and the performance of our energy harvester, where the resonance free vibration of unimorph cantilever with one permanent magnet under a rather high frequency was induced by the artificial low frequency vibration. The counterpart magnet attached on the pendulum. Next, we equipped the counterpart permanent magnet pendulum, which was fluctuated under a very low frequency by the human walking, and the piezoelectric cantilever, which had the permanent magnet at the end. The low-to-high frequency convert "hybrid system" can be characterized as an enhanced energy harvest one. We examined and obtained maximum values of voltage and power in this system, as 1.2V and 1.2 µW. Those results show the possibility to apply for the energy harvester in the portable and implantable Bio-MEMS devices. PMID:23366218

Minami, Y; Nakamachi, E

2012-01-01

176

Multi-source energy harvesting for wireless SHM systems  

NASA Astrophysics Data System (ADS)

In wireless SHM systems, energy harvesting technology is essential for a reliable long-term energy supply for wireless sensors. Conventional wireless SHM systems using single source energy harvesting (vibration, solar, and etc.) have limitations because it could not be operated adequately without enough ambient energy present. To overcome this obstacle, multi-source energy harvesting which utilizes several ambient energy sources simultaneously is necessary to accumulate enough electrical energy to power wireless embedded sensor nodes. This study proposes a multi-source energy harvesting technique using a MISO (Multiple Input, Single Output) circuit board developed and studied by the authors. For multi-source energy harvesting, piezoelectric bimorph and electro-magnetic energy harvesters are excited at the first natural frequency of each harvester, 126.7 and 12.5 Hz, respectively. Then, generated voltage from each energy harvester is combined using the MISO circuit and then used to charge a 0.1 F capacitor. Combined energy harvesting results presented better performance than that of a single energy source, demonstrating that this multi-source system could be a promising energy harvesting solution for wireless sensing systems.

Choi, Mijin; Farinholt, Kevin M.; Anton, Steven; Lee, Jung-Ryul; Park, Gyuhae

2013-03-01

177

Energy Harvesting Using a Piezoelectric ``Cymbal'' Transducer in Dynamic Environment  

Microsoft Academic Search

In this study, we investigated the capability of harvesting the electrical energy from mechanical vibrations in a dynamic environment through a ``cymbal'' piezoelectric transducer. Targeted mechanical vibrations lie in the range of 50-150 Hz with force amplitude in the order of 1 kN (automobile engine vibration level). It was found that under such severe stress conditions the metal-ceramic composite transducer

Hyeoung Woo Kim; Amit Batra; Shashank Priya; Kenji Uchino; Douglas Markley; Robert E. Newnham; Heath F. Hofmann

2004-01-01

178

Tree-inspired piezoelectric energy harvesting  

NASA Astrophysics Data System (ADS)

We design and test micro-watt energy-harvesters inspired by tree trunks swaying in the wind. A uniform flow vibrates a linear array of four cylinders affixed to piezoelectric energy transducers. Particular attention is paid to measuring the energy generated as a function of cylinder spacing, flow speed, and relative position of the cylinder within the array. Peak power is generated using cylinder center-to-center spacings of 3.3 diameters and flow speeds in which the vortex shedding frequency is 1.6 times the natural frequency of the cylinders. Using these flow speeds and spacings, the power generated by downstream cylinders can exceed that of leading cylinders by more than an order of magnitude. We visualize the flow in this system by studying the behavior of a dynamically matched flowing soap film with imbedded styrofoam disks. Our qualitative visualizations suggest that peak energy harvesting occurs under conditions in which vortices have fully detached from the leading cylinder.

Hobbs, William B.; Hu, David L.

2012-01-01

179

A wideband magnetic energy harvester  

NASA Astrophysics Data System (ADS)

A wideband magnetic energy harvester is proposed by using a number of multiferroic composite fibers of different lengths which are connected in parallel or series. The structural theory is employed to characterize the magnetoelectroelastic behavior of the fibers. A global circuit analysis is then performed. It is shown that such a structure of energy harvester is capable of collecting the ambient magnetic energy over a wide frequency range.

Zhang, C. L.; Chen, W. Q.

2010-03-01

180

Nonlinear interface between the piezoelectric harvesting structure and the modulating circuit of an energy harvester with a real storage battery  

Microsoft Academic Search

This paper studies the performance of an energy harvester with a piezoelectric bimorph (PB) and a real electrochemical battery (ECB), both are connected as an integrated system through a rectified dc-dc converter (DDC). A vibrating PB can scavenge energy from the operating environment by the electromechanical coupling. A DDC can effectively match the optimal output voltage of the harvesting structure

Yuantai Hu; Huan Xue; Ting Hu; Hongping Hu

2008-01-01

181

A coupled piezoelectric–electromagnetic energy harvesting technique for achieving increased power output through damping matching  

Microsoft Academic Search

Vibration energy harvesting is being pursued as a means to power wireless sensors and ultra-low power autonomous devices. From a design standpoint, matching the electrical damping induced by the energy harvesting mechanism to the mechanical damping in the system is necessary for maximum efficiency. In this work two independent energy harvesting techniques are coupled to provide higher electrical damping within

Vinod R Challa; M G Prasad; Frank T Fisher

2009-01-01

182

Harvested power and sensitivity analysis of vibrating shoe-mounted piezoelectric cantilevers  

NASA Astrophysics Data System (ADS)

This paper presents a preliminary investigation on energy harvesting from human walking via piezoelectric vibrating cantilevers. Heel accelerations during human gait are established by correlating data gathered from the literature with direct experimental measurements. All the observed relevant features are synthesized in a typical (standard) acceleration signal, used in subsequent numerical simulations. The transient electromechanical response and the harvested power of a shoe-mounted bimorph cantilever excited by the standard acceleration signal is computed by numerical simulations and compared with measurements on a real prototype. A sensitivity analysis is finally developed to estimate the mean harvested power for a wide range of scavenger configurations. Acceptability criteria based on imposed geometrical constraints and resistance strength limits (e.g. fatigue limit) are also established. This analysis allows a quick preliminary screening of harvesting performance of different scavenger configurations.

Moro, L.; Benasciutti, D.

2010-11-01

183

Damping as a result of piezoelectric energy harvesting  

Microsoft Academic Search

Systems that harvest or scavenge energy from their environments are of considerable interest for use in remote power supplies. A class of such systems exploits the motion or deformation associated with vibration, converting the mechanical energy to electrical, and storing it for later use; some of these systems use piezoelectric materials for the direct conversion of strain energy to electrical

G. A. Lesieutre; G. K. Ottman; H. F. Hofmann

2004-01-01

184

Performance of a piezoelectric energy harvester driven by air flow  

NASA Astrophysics Data System (ADS)

A turbulent wind source for possible energy harvesting is considered. To increase the amplitude of vibration, we apply a magnetopiezoelastic oscillator having a double well Duffing potential. The output voltage response of the system for different level of wind excitations is analyzed. The energy harvesting appeared to be the most efficient for the conditions close to the stochastic resonance region where the potential barrier was overcame.

Kitio Kwuimy, C. A.; Litak, G.; Borowiec, M.; Nataraj, C.

2012-01-01

185

Energy harvesting using RF MEMS  

Microsoft Academic Search

This paper presents a novel technology which provides a promising solution for designing self-powered microsystems. Micro-Electro Mechanical System (MEMS) energy harvesting is an emerging alternative for scavenging energy from natural sources. It has extensive potential in wireless sensor applications to provide a natural energy source that is essentially inexhaustible. It is an increasingly attractive alternative to costly batteries. This essentially

Yunhan Huang; Ravi Doraiswami; Michael Osterman; Michael Pecht

2010-01-01

186

Piezoelectric Energy Harvesting Device Optimization by Synchronous Electric Charge Extraction  

Microsoft Academic Search

This article presents a nonlinear approach to optimize the power flow of vibration-based piezoelectric energy-harvesting devices. This self-adaptive principle is based on a particular synchronization between extraction of the electric charge produced by the piezoelectric element and the system vibrations, which maximizes the mechanical to electrical energy conversion. An analytical expression of the optimal power flow is derived from a

Elie Lefeuvre; Adrien Badel; Claude Richard; Daniel Guyomar

2005-01-01

187

Energy harvesting: a key to wireless sensor nodes  

NASA Astrophysics Data System (ADS)

Energy harvesting has enabled new operational concepts in the growing field of wireless sensing. A novel energy harvesting device driven by aeroelastic flutter vibrations has been developed and could be used to complement existing environmental energy harvesters such as solar cells in wireless sensing applications. An analytical model of the mechanical, electromechanical, and aerodynamic systems suitable for designing aeroelastic energy harvesters for various flow applications are derived and presented. Wind tunnel testing was performed with a prototype energy harvester to characterize the power output and flutter frequency response of the device over its entire range of operating wind speeds. Finally, two wing geometries, a flat plate and a NACA 0012 airfoil were tested and compared.

Bryant, Matthew; Garcia, Ephrahim

2009-07-01

188

Energy-harvesting shock absorber with a mechanical motion rectifier  

NASA Astrophysics Data System (ADS)

Energy-harvesting shock absorbers are able to recover the energy otherwise dissipated in the suspension vibration while simultaneously suppressing the vibration induced by road roughness. They can work as a controllable damper as well as an energy generator. An innovative design of regenerative shock absorbers is proposed in this paper, with the advantage of significantly improving the energy harvesting efficiency and reducing the impact forces caused by oscillation. The key component is a unique motion mechanism, which we called ‘mechanical motion rectifier (MMR)’, to convert the oscillatory vibration into unidirectional rotation of the generator. An implementation of a MMR-based harvester with high compactness is introduced and prototyped. A dynamic model is created to analyze the general properties of the motion rectifier by making an analogy between mechanical systems and electrical circuits. The model is capable of analyzing electrical and mechanical components at the same time. Both simulation and experiments are carried out to verify the modeling and the advantages. The prototype achieved over 60% efficiency at high frequency, much better than conventional regenerative shock absorbers in oscillatory motion. Furthermore, road tests are done to demonstrate the feasibility of the MMR shock absorber, in which more than 15 Watts of electricity is harvested while driving at 15 mph on a smooth paved road. The MMR-based design can also be used for other applications of vibration energy harvesting, such as from tall buildings or long bridges.

Li, Zhongjie; Zuo, Lei; Kuang, Jian; Luhrs, George

2013-02-01

189

Ocean Wave Energy Harvesting Devices.  

National Technical Information Service (NTIS)

Development of an ocean wave energy-harvesting device that can be used as a renewable energy source for ocean monitoring systems. The core technology is a mass-spring based high efficiency, low frequency linear generator that was integrated to a spar buoy...

I. E. Childress J. T. Cheung

2007-01-01

190

Broadband energy harvesting using nonlinear 2-DOF configuration  

NASA Astrophysics Data System (ADS)

Vibration energy harvesting using piezoelectric material has received great research interest in the recent years. To enhance the performance of piezoelectric energy harvesters, one important concern is to increase their operating bandwidth. Various techniques have been proposed for broadband energy harvesting, such as the resonance tuning approach, the frequency up-conversion technique, the multi-modal harvesting and the nonlinear technique. Usually, a nonlinear piezoelectric energy harvester can be easily developed by introducing a magnetic field. Either mono-stable or bi-stable response can be achieved using different magnetic configurations. However, most of the research work for nonlinear piezoelectric energy harvesting has focused on the SDOF cantilever beam. A recently reported linear 2-DOF harvester can achieve two close resonant frequencies with significant power outputs. However, for this linear configuration, although a broader bandwidth can be achieved, there exists a deep valley in-between the two response peaks. The presence of the valley will greatly deteriorate the performance of the energy harvester. To overcome this limitation, a nonlinear 2-DOF piezoelectric energy harvester is proposed in this article. This nonlinear harvester is developed from its linear counterpart by incorporating a magnetic field using a pair of magnets. Experimental parametric study is carried out to investigate the behavior of such harvester. With different configurations, both mono-stable and bi-stable behaviors are observed and studied. An optimal configuration of the nonlinear harvester is thus obtained, which can achieve significantly wider bandwidth than the linear 2-DOF harvester and at the same time overcome its limitation.

Wu, Hao; Tang, Lihua; Avvari, Panduranga Vittal; Yang, Yaowen; Soh, Chee Kiong

2013-04-01

191

Design of a multiresonant beam for broadband piezoelectric energy harvesting  

NASA Astrophysics Data System (ADS)

This paper describes initial investigations into the behavior of a mechanical system for a proposed novel energy harvesting device. The device comprises a clamped-clamped beam piezoelectric fiber composite generator with side mounted cantilevers. These side mounted cantilevers are tuned by added masses to be resonant at different frequencies. A Rayleigh-Ritz model has been developed to predict the vibration response of the device and results from this model and from the real system are compared. The mechanical aspects of the device show a wide band energy harvesting characteristic in comparison to a single cantilever piezoelectric harvester.

Qi, Shaofan; Shuttleworth, Roger; Olutunde Oyadiji, S.; Wright, Jan

2010-09-01

192

Resonance tuning of piezoelectric vibration energy scavenging generators using compressive axial preload  

Microsoft Academic Search

Vibration energy scavenging, harvesting ambient vibrations in structures for conversion into usable electricity, provides a potential power source for emerging technologies including wireless sensor networks. Most vibration energy scavenging devices developed to date operate effectively at a single specific frequency dictated by the device’s design. However, for this technology to be commercially viable, vibration energy scavengers that generate usable power

Eli S Leland; Paul K Wright

2006-01-01

193

Power Conservation in Energy Harvesting Sensor Networks  

Microsoft Academic Search

?We examine energy harvesting sensor networks, more specifically, a sensor network using the Geographic Routing with Environmental Energy Supply (GREES) algorithm. We start with a discussion of other sources of energy conservation both in energy harvesting and non-energy harvesting sensor networks. Ideas presented in these works are combined where possible with the GREES algorithm. A sensor network was actually built

Roberts Timothy A M. A. Sc

2011-01-01

194

Ocean Wave Energy Harvesting Devices.  

National Technical Information Service (NTIS)

Development of a mechanically sound buoy design. which generated 10W average power in Beaufort Sea State I. and showed potential for up to 20W in Sea State 4. Development of a wave energy harvesting buoy capable of generating 2W in Sea State I. and with p...

E. F. Childress J. T. Cheung

2008-01-01

195

Sunrise for energy harvesting products  

Microsoft Academic Search

Hundreds of companies and research institutes in the US, Europe, and Japan are working on energy harvesting technology, and the industry is attracting millions of dollars in venture capital. But despite these considerable investments, progress in bringing this technology to market has been slow. Alternative power sources contribute only a fraction to worldwide power generation, and the load on the

J. Krikke

2005-01-01

196

An electromechanical finite element model for piezoelectric energy harvester plates  

NASA Astrophysics Data System (ADS)

Vibration-based energy harvesting has been investigated by several researchers over the last decade. The goal in this research field is to power small electronic components by converting the waste vibration energy available in their environment into electrical energy. Recent literature shows that piezoelectric transduction has received the most attention for vibration-to-electricity conversion. In practice, cantilevered beams and plates with piezoceramic layers are employed as piezoelectric energy harvesters. The existing piezoelectric energy harvester models are beam-type lumped parameter, approximate distributed parameter and analytical distributed parameter solutions. However, aspect ratios of piezoelectric energy harvesters in several cases are plate-like and predicting the power output to general (symmetric and asymmetric) excitations requires a plate-type formulation which has not been covered in the energy harvesting literature. In this paper, an electromechanically coupled finite element (FE) plate model is presented for predicting the electrical power output of piezoelectric energy harvester plates. Generalized Hamilton's principle for electroelastic bodies is reviewed and the FE model is derived based on the Kirchhoff plate assumptions as typical piezoelectric energy harvesters are thin structures. Presence of conductive electrodes is taken into account in the FE model. The predictions of the FE model are verified against the analytical solution for a unimorph cantilever and then against the experimental and analytical results of a bimorph cantilever with a tip mass reported in the literature. Finally, an optimization problem is solved where the aluminum wing spar of an unmanned air vehicle (UAV) is modified to obtain a generator spar by embedding piezoceramics for the maximum electrical power without exceeding a prescribed mass addition limit.

de Marqui Junior, Carlos; Erturk, Alper; Inman, Daniel J.

2009-10-01

197

An Efficient Piezoelectric Energy Harvesting Interface Circuit Using a Bias-Flip Rectifier and Shared Inductor  

Microsoft Academic Search

Harvesting ambient vibration energy through piezoelectric means is a popular energy harvesting technique which can potentially supply 10-100's of ¿W of available power. One of the main limitations of existing piezoelectric harvesters is in their interface circuitry. In this paper, a bias-flip rectifier circuit that can improve the power extraction capability from piezoelectric harvesters over conventional full-bridge rectifiers and voltage

Yogesh K. Ramadass; Anantha P. Chandrakasan

2010-01-01

198

Ferrofluid based micro-electrical energy harvesting  

NASA Astrophysics Data System (ADS)

Innovations in energy harvesting have seen a quantum leap in the last decade. With the introduction of low energy devices in the market, micro energy harvesting units are being explored with much vigor. One of the recent areas of micro energy scavenging is the exploitation of existing vibrational energy and the use of various mechanical motions for the same, useful for low power consumption devices. Ferrofluids are liquids containing magnetic materials having nano-scale permanent magnetic dipoles. The present work explores the possibility of the use of this property for generation of electricity. Since the power generation is through a liquid material, it can take any shape as well as response to small acceleration levels. In this work, an electromagnet-based micropower generator is proposed to utilize the sloshing of the ferrofluid within a controlled chamber which moves to different low frequencies. As compared to permanent magnet units researched previously, ferrofluids can be placed in the smallest of containers of different shapes, thereby giving an output in response to the slightest change in motion. Mechanical motion from 1- 20 Hz was able to give an output voltage in mV's. In this paper, the efficiency and feasibility of such a system is demonstrated.

Purohit, Viswas; Mazumder, Baishakhi; Jena, Grishma; Mishra, Madhusha

2013-03-01

199

Energy harvesting materials  

NASA Astrophysics Data System (ADS)

It is shown how key features of natural photosynthesis can be emulated in novel materials based on photoactive multichromophore arrays and crystals. A major consideration in the design of such systems is the means of channeling electronic excitation from sites of light absorption to centers where it is stored or released. Storage is often achieved by driving charge separation or, for the longer term, a more complex chemical reaction whilst rapid release is commonly associated with frequency up-converted emission. In each case channeling to the conversion site generally entails a multi-step energy transfer mechanism whose efficiency is determined by the arrangement and electronic properties of the array chromophores or ions, guided in the more complex systems by a spectroscopic gradient that promotes overall directionality. The functional cascade molecules known as photoactive dendrimers are exemplars of this approach. The latest developments involve new mechanisms for concerted excitation transfer in multichromophore systems, leading towards the tailoring and exploitation of optical nonlinearities for high intensity energy pooling applications.

Andrews, David L.

2002-06-01

200

Strength analysis of piezoceramic materials for structural considerations in energy harvesting for UAVs  

NASA Astrophysics Data System (ADS)

Vibration energy harvesting has received considerable attention in the research community over the past decade. Typical vibration harvesting systems are designed to be added on to existing host structures and capture ambient vibration energy. An interesting application of vibration energy harvesting exists in unmanned aerial vehicles (UAVs), where a multifunctional approach, as opposed to the traditional method, is needed due to weight and aerodynamic considerations. The authors propose a multifunctional design for energy harvesting in UAVs where the piezoelectric harvesting device is integrated into the wing of a UAV and provides energy harvesting, energy storage, and load bearing capability. The brittle piezoceramic layer of the harvester is a critical member in load bearing applications; therefore, it is the goal of this research to investigate the bending strength of various common piezoceramic materials. Three-point bend tests are carried out on several piezoelectric ceramics including monolithic piezoceramics PZT-5A and PZT-5H, single crystal piezoelectric PMN-PZT, and commercially packaged QuickPack devices. Bending strength results are reported and can be used as a design tool in the development of piezoelectric vibration energy harvesting systems in which the active device is subjected to bending loads.

Anton, S. R.; Erturk, A.; Inman, D. J.

2010-03-01

201

Development of MEMS piezoelectric energy harvesters  

NASA Astrophysics Data System (ADS)

The research of powering devices in a microwatt range has been activated and developed by the emergence of low-power Very Large Scale Integration (VLSI) technology in the past few years. The powering devices require a size that is compatible with the application, sufficient power, and extended lifetime using permanent and ubiquitous energy sources. The piezoelectric energy harvester using vibration sources is attractive due to its high conversion efficiency, simple design for miniaturizing, and lack of external voltage source. While bulk piezoelectric energy harvesters produce enough power for a few tens of mW, the insufficient power is still a major issue during miniaturizing into micro size. The piezoelectric energy harvester was fabricated by micro-electro-mechanical systems (MEMS) and developed to enhance its output power. It was designed to be resonated at the frequency range of ambient vibration source (50˜300 Hz) and convert the mechanical stress to electricity by piezoelectric thin film. The cantilever structure was chosen in this study due to its large strain, and a big proof mass at the end of tip was integrated for the same reason. This study focuses on three specific issues related to the robust fabrication process, including the integration of piezoelectric thin film, structure design for high power density, and the reliability of device. The Lead Zirconate Titanate (PZT) thin films were prepared by a sol-gel process and were used to fabricate energy harvesters by an optimized MEMS process. The properties of PZT thin film were studied considering the substrate effect, heat treatment, and thickness effects. The fabricated energy harvester produced 769 mVpk-pk, and 6.72 muW with the optimal resistive load of 11 kO at 127 Hz of resonant frequency. The device had dimensions of about 4 mm(L) x 2 mm(w) x 0.021 mm(H), and the Si proof mass had dimensions of 3 mm(L) x 2 mm(W) x 0.5 mm(H). Beyond this result, the technical platform for the robust fabrication process was established on a Deep Reactive Ion Etcher (DRIE). The plasma etching using DRIE was optimized to prevent damage of the PZT film and to obtain uniform and precise dimension control. The trapezoidal shape of the cantilever was demonstrated to enhance the power density by stress distribution on the PZT film. The geometry change in cantilever shape distributed the strain on piezoelectric film and improved the output power ˜40% higher than that of the rectangular shape due to nonlinear piezoelectric properties. The multi-beam arrays were designed to obtain a multiplied electric power effect as if as number of cantilevers was used. The multibeam arrayed design requires the uniform machining to match the unified resonant frequency of each cantilever structure. Based on the optimized fabrication process, the cantilever array that consists of four cantilevers generated 18.39 muA and 1.352 muW with 4 kO of optimized resistive load in parallel connection under 1 G of acceleration force. The result was exactly four times higher power and current than that of individual cantilever. Finally, reliability tests were performed for the piezoelectric MEMS energy harvester considering the number of cyclic loads and temperature, and the degradation of PZT during fabrication was also investigated.

Park, Jung-Hyun

202

Power management for energy harvesting wireless sensors  

NASA Astrophysics Data System (ADS)

The objective of this work was to demonstrate smart wireless sensing nodes capable of operation at extremely low power levels. These systems were designed to be compatible with energy harvesting systems using piezoelectric materials and/or solar cells. The wireless sensing nodes included a microprocessor, on-board memory, sensing means (1000 ohm foil strain gauge), sensor signal conditioning, 2.4 GHz IEEE 802.15.4 radio transceiver, and rechargeable battery. Extremely low power consumption sleep currents combined with periodic, timed wake-up was used to minimize the average power consumption. Furthermore, we deployed pulsed sensor excitation and microprocessor power control of the signal conditioning elements to minimize the sensors" average contribution to power draw. By sleeping in between samples, we were able to demonstrate extremely low average power consumption. At 10 Hz, current consumption was 300 microamps at 3 VDC (900 microwatts); at 5 Hz: 400 microwatts, at 1 Hz: 90 microwatts. When the RF stage was not used, but data were logged to memory, consumption was further reduced. Piezoelectric strain energy harvesting systems delivered ~2000 microwatts under low level vibration conditions. Output power levels were also measured from two miniature solar cells; which provided a wide range of output power (~100 to 1400 microwatts), depending on the light type & distance from the source. In summary, system power consumption may be reduced by: 1) removing the load from the energy harvesting & storage elements while charging, 2) by using sleep modes in between samples, 3) pulsing excitation to the sensing and signal conditioning elements in between samples, and 4) by recording and/or averaging, rather than frequently transmitting, sensor data.

Arms, S. W.; Townsend, C. P.; Churchill, D. L.; Galbreath, J. H.; Mundell, S. W.

2005-05-01

203

Energy Harvesting for Aerospace Structural Health Monitoring Systems  

NASA Astrophysics Data System (ADS)

Recent research into damage detection methodologies, embedded sensors, wireless data transmission and energy harvesting in aerospace environments has meant that autonomous structural health monitoring (SHM) systems are becoming a real possibility. The most promising system would utilise wireless sensor nodes that are able to make decisions on damage and communicate this wirelessly to a central base station. Although such a system shows great potential and both passive and active monitoring techniques exist for detecting damage in structures, powering such wireless sensors nodes poses a problem. Two such energy sources that could be harvested in abundance on an aircraft are vibration and thermal gradients. Piezoelectric transducers mounted to the surface of a structure can be utilised to generate power from a dynamic strain whilst thermoelectric generators (TEG) can be used to generate power from thermal gradients. This paper reports on the viability of these two energy sources for powering a wireless SHM system from vibrations ranging from 20 to 400Hz and thermal gradients up to 50°C. Investigations showed that using a single vibrational energy harvester raw power levels of up to 1mW could be generated. Further numerical modelling demonstrated that by optimising the position and orientation of the vibrational harvester greater levels of power could be achieved. However using commercial TEGs average power levels over a flight period between 5 to 30mW could be generated. Both of these energy harvesting techniques show a great potential in powering current wireless SHM systems where depending on the complexity the power requirements range from 1 to 180mW.

Pearson, M. R.; Eaton, M. J.; Pullin, R.; Featherston, C. A.; Holford, K. M.

2012-08-01

204

On the efficiencies of piezoelectric energy harvesting circuits towards storage device voltages  

NASA Astrophysics Data System (ADS)

Using piezoelectric elements to harvest energy from ambient vibrations has been of great interest over the past few years. Due to the relatively low power output of piezoelectric materials, energy storage devices are used to accumulate harvested energy for intermittent use. Piezoelectric energy harvesting circuits have two schemes: one-stage and two-stage energy harvesting. A one-stage energy harvesting scheme includes a conventional diode bridge rectifier and an energy storage device. In recent years, two-stage energy harvesting circuits have been explored. While the results shown in previous research and development are promising, there are still some issues that need to be studied. Energy storage devices such as rechargeable batteries and supercapacitors have different cell voltages. Moreover, the storage cells can be connected in series to increase the voltage range. The storage device voltage is an important factor that influences the energy harvesting efficiency. This paper will study the efficiencies of the energy harvesting circuits considering the storage device voltages. For one-stage energy harvesting, expressions are derived to calculate the efficiencies towards different storage device voltages and verified by experiments. For two-stage energy harvesting circuits, theoretical efficiency expressions are derived and verified by PSPICE simulations. These two energy harvesting schemes are also compared. The results show that a one-stage energy harvesting scheme can achieve higher efficiency than the two-stage scheme towards a range of energy storage voltages.

Guan, M. J.; Liao, W. H.

2007-04-01

205

Adaptive duty cycling for energy harvesting systems  

Microsoft Academic Search

Harvesting energy from the environment is feasible in many applications to ameliorate the energy limitations in sensor networks. In this paper, we present an adaptive duty cycling algorithm that allows energy harvesting sensor nodes to autonomously adjust their duty cycle according to the energy availability in the environment. The algorithm has three objectives, namely (a) achieving energy neutral operation, i.e.,

Jason Hsu; Sadaf Zahedi; Aman Kansal; Mani B. Srivastava; Vijay Raghunathan

2006-01-01

206

Power management in energy harvesting sensor networks  

Microsoft Academic Search

Power management is an important concern in sensor networks, because a tethered energy infrastructure is usually not available and an obvious concern is to use the available battery energy efficiently. However, in some of the sensor networking applications, an additional facility is available to ameliorate the energy problem: harvesting energy from the environment. Certain considerations in using an energy harvesting

Aman Kansal; Jason Hsu; Sadaf Zahedi; Mani B. Srivastava

2007-01-01

207

Performance modeling of unmanned aerial vehicles with on-board energy harvesting  

Microsoft Academic Search

The concept of energy harvesting in unmanned aerial vehicles (UAVs) has received much attention in recent years. Solar powered flight of small aircraft dates back to the 1970s when the first fully solar flight of an unmanned aircraft took place. Currently, research has begun to investigate harvesting ambient vibration energy during the flight of UAVs. The authors have recently developed

Steven R. Anton; Daniel J. Inman

2011-01-01

208

Fabrication and characterization of a low frequency electromagnetic energy harvester  

NASA Astrophysics Data System (ADS)

This paper presents the fabrication and characterization of an AA size electromagnetic energy transducer based on vibration. A magnetic spring technique is used to scavenge energy from low frequency external vibration. The output of the harvester is maximized by optimizing the mass of moving and fixed magnets, coil width, coil position and load resistance through a comprehensive experimental analysis. The prototype can generate an open circuit voltage of 3.961 V and 1.18 mW average power at a load resistance of 97 ? with 9 Hz resonance frequency and 0.5 mm displacement.

Foisal, Abu Riduan Md.; Chung, Gwiy-Sang

2012-07-01

209

Efficiency of harvesting energy from colored noise by linear oscillators  

NASA Astrophysics Data System (ADS)

We investigate the performance of a linear electromechanical oscillator as an energy harvester of finite-bandwidth random vibrations. We derive exact analytical expressions for the net electrical power and the efficiency of the conversion of the power supplied by the noise into electrical power for arbitrary colored noise. We apply our results to the important case of exponentially correlated noise and discuss the tuning of parameters to achieve good performance of the device.

Méndez, Vicenç; Campos, Daniel; Horsthemke, Werner

2013-08-01

210

Analysis and design of roof turbine ventilator for wind energy harvest  

Microsoft Academic Search

Harvesting energy using roof turbine ventilator and electroactive material has been investigated to verify its performance. Since electric power gained from a single piece of regular size is usually small, auxiliary device to vibrate multiple pieces of electroactive materials in order to harvest more power is required. In this paper, an attempt of using the developed nozzle wind collector associated

Yung Ting; H. Gunawan; A. Sugondo; Kun-Lin Hsu; Jyh-Tong Teng

2010-01-01

211

Wireless communication and energy harvesting in automobiles  

Microsoft Academic Search

Using wireless communication and energy harvest- ing in automobiles might have significant advantages considering dependability (no wires and contacts) and weight (no cable tree). In this paper, we give a brief overview of the related technologies, surrounding conditions, and methods for design and optimization. As examples, we focus on methods for harvesting kinetic energy and wireless transmission in a tire

Stefan Mahlknecht; Tom J. Kazmierski; Christoph Grimm; Leran Wang

2011-01-01

212

Nonlinear Behavior of an Electrostatic Energy Harvester Under Wide and Narrowband Excitation  

Microsoft Academic Search

This paper investigates an electrostatic vibration energy harvester that displays rich nonlinear behavior including jumps during frequency sweeps and broadening of the spectrum with increasing levels of broadband vibration. We demonstrate that the measured nonlinear phenomena can be adequately described by a lumped model with a nonlinear beam displaying both spring softening and hardening. Our results show that considerable bandwidth

Lars Geir Whist Tvedt; Duy Son Nguyen; Einar Halvorsen

2010-01-01

213

Bi-stable energy harvesting based on a simply supported piezoelectric buckled beam  

NASA Astrophysics Data System (ADS)

Bi-stable piezoelectric energy harvester has been found as a promising structure for vibration energy harvesting. This paper presents a high performance and simple structure bi-stable piezoelectric energy harvester based on simply supported piezoelectric buckled beam. The potential energy function is established theoretically, and electrical properties of the device under different axial compressive displacements, excitation frequencies, and accelerations are investigated systematically. Experimental results demonstrate that the output properties and bandwidth of the bi-stable nonlinear energy harvester under harmonic mechanical excitation are improved dramatically compared with the traditional linear energy harvester. The device demonstrates the potential in energy harvesting application to low-power portable electronics and wireless sensor nodes.

Xu, Chundong; Liang, Zhu; Ren, Bo; Di, Wenning; Luo, Haosu; Wang, Dong; Wang, Kailing; Chen, Zhifang

2013-09-01

214

Low energy dissipation electric circuit for energy harvesting  

Microsoft Academic Search

A low energy dissipation circuit is proposed to achieve more effective energy harvesting, called 'synchronized switch harvesting on inductor (SSHI)'. The proposed circuit only has two diodes, while the original SSHI circuit has four diodes comprising a diode bridge. It thus reduces the voltage drop during the energy-harvesting process, because the actual diodes have forward voltage regarded as equivalent electrical

Kanjuro Makihara; Junjiro Onoda; Takeya Miyakawa

2006-01-01

215

Energy harvesting MEMS device based on thin film piezoelectric cantilevers  

Microsoft Academic Search

A thin film lead zirconate titanate Pb(Zr,Ti)O3 (PZT), energy harvesting MEMS device is developed to enable self-supportive sensors for in-service integrity monitoring of\\u000a large social and environmental infrastructures at remote locations. It is designed to resonate at specific frequencies of\\u000a an external vibrational energy source, thereby creating electrical energy via the piezoelectric effect. Our cantilever device\\u000a has a PZT\\/SiNx bimorph

W. J. Choi; Y. Jeon; J.-H. Jeong; R. Sood; S. G. Kim

2006-01-01

216

Parametric design study of an aeroelastic flutter energy harvester  

NASA Astrophysics Data System (ADS)

This paper investigates a novel mechanism for powering wireless sensors or low power electronics by extracting energy from an ambient fluid flow using a piezoelectric energy harvester driven by aeroelastic flutter vibrations. The energy harvester makes use of a modal convergence flutter instability to generate limit cycle bending oscillations of a cantilevered piezoelectric beam with a small flap connected to its free end by a revolute joint. The critical flow speed at which destabilizing aerodynamic effects cause self-excited vibrations of the structure to emerge is essential to the design of the energy harvester. This value sets the lower bound on the operating wind speed and frequency range of the system. A system of coupled equations that describe the structural, aerodynamic, and electromechanical aspects of the system are used to model the system dynamics. The model uses unsteady aerodynamic modeling to predict the aerodynamic forces and moments acting on the structure and to account for the effects of vortices shed by the flapping wing, while a modal summation technique is used to model the flexible piezoelectric structure. This model is applied to examine the effects on the cut-in wind speed of the system when several design parameters are tuned and the size and mass of the system is held fixed. The effects on the aeroelastic system dynamics and relative sensitivity of the flutter stability boundary are presented and discussed. Experimental wind tunnel results are included to validate the model predictions.

Bryant, Matthew; Wolff, Eric; Garcia, Ephrahim

2011-03-01

217

Investigation of electrostrictive polymers for energy harvesting  

Microsoft Academic Search

The recent development of electrostrictive polymers has generated new opportunities for high-strain actuators. At the current time, the investigation of using electrostrictive polymer for energy harvesting, or mechanical to electrical energy conversion, is beginning to show its potential for this application. In this paper we discuss the mechanical and electrical boundary conditions for maximizing the energy harvesting density and mechanical-to-electrical

Yiming Liu; Kai Liang Ren; Heath F. Hofmann; Qiming Zhang

2005-01-01

218

Piezoelectric energy harvesting from transverse galloping of bluff bodies  

NASA Astrophysics Data System (ADS)

The concept of harvesting energy from transverse galloping oscillations of a bluff body with different cross-section geometries is investigated. The energy is harvested by attaching a piezoelectric transducer to the transverse degree of freedom of the body. The power levels that can be generated from these vibrations and the variations of these levels with the load resistance, cross-section geometry, and freestream velocity are determined. A representative model that accounts for the transverse displacement of the bluff body and harvested voltage is presented. The quasi-steady approximation is used to model the aerodynamic loads. A linear analysis is performed to determine the effects of the electrical load resistance and the cross-section geometry on the onset of galloping, which is due to a Hopf bifurcation. The normal form of this bifurcation is derived to determine the type (supercritical or subcritical) of the instability and to characterize the effects of the linear and nonlinear parameters on the level of harvested power near the bifurcation. The results show that the electrical load resistance and the cross-section geometry affect the onset speed of galloping. The results also show that the maximum levels of harvested power are accompanied with minimum transverse displacement amplitudes for all considered (square, D, and triangular) cross-section geometries, which points to the need for performing a coupled analysis of the system.

Abdelkefi, A.; Hajj, M. R.; Nayfeh, A. H.

2013-01-01

219

Exploration of new cymbal design in energy harvesting  

NASA Astrophysics Data System (ADS)

Harvesting wasted energy and converting it into electrical energy to use as needed is an emerging technology area. In this work, a new design of a cymbal energy harvester is developed and tested to validate analytical energy generating performance. Cymbal transducers have been demonstrated to be beneficial as energy harvesters for vibrating systems under modest load and frequency. In this paper a new design is adopted using a unimorph circular piezoelectric disc between the metal end caps to deal with higher loads. Simple analysis for the new cymbal design to predict voltage output was first conducted. The new cymbal design, 25.4 mm diameter and 8.2 mm thickness, was then fabricated and tested on the load frame with up to 324 lb load and 1 Hz frequency to measure output voltages. This device could be used in numerous applications for potentially self sustaining sensors or other electronic devices. By changing the structure between the metal end caps of cymbal harvesters the new design could be extended in higher load applications.

Arnold, Daniel; Kinsel, William; Clark, William W.; Mo, Changki

2011-03-01

220

A low profile vibro-impacting energy harvester with symmetrical stops  

NASA Astrophysics Data System (ADS)

This paper reports on an investigation into the use of a vibro-impact approach to construct a relatively broadband kinetic energy harvester. Potentially, the vibro-impacting process may be exploited as an autotuning mechanism for energy harvesting in an environment where the source vibration spectrum varies in time, such as an aircraft in flight. The energy harvester examined in this paper is based on a vibro-impacting oscillator with double-sided, symmetrical, piezoelectric bimorph-stops. The energy harvester operates in the frequency range of 100-113 Hz and has a (non-optimized) maximum energy of 5.3 mW from an rms host vibration of 450 mG.

Moss, Scott; Barry, Alex; Powlesland, Ian; Galea, Steve; Carman, Gregory P.

2010-12-01

221

Energy Harvesting Using a Thermoelectric Material.  

National Technical Information Service (NTIS)

A novel energy harvesting system and method utilizing a thermoelectric having a material exhibiting a large thermally induced strain (TIS) due to a phase transformation and a material exhibiting a stress induced electric field is introduced. A material th...

N. Nersessian G. P. Carman H. B. Radousky

2005-01-01

222

Development of a biomechanical energy harvester  

Microsoft Academic Search

BACKGROUND: Biomechanical energy harvesting–generating electricity from people during daily activities–is a promising alternative to batteries for powering increasingly sophisticated portable devices. We recently developed a wearable knee-mounted energy harvesting device that generated electricity during human walking. In this methods-focused paper, we explain the physiological principles that guided our design process and present a detailed description of our device design with

Qingguo Li; Veronica Naing; J Maxwell Donelan

2009-01-01

223

Low power interface IC's for electrostatic energy harvesting applications  

NASA Astrophysics Data System (ADS)

The application of wireless distributed micro-sensor systems ranges from equipment diagnostic and control to real time structural and biomedical monitoring. A major obstacle in developing autonomous micro-sensor networks is the need for local electric power supply, since using a battery is often not a viable solution. This void has sparked significant interest in micro-scale power generators based on electrostatic, piezoelectric and electromagnetic energy conversion that can scavenge ambient energy from the environment. In comparison to existing energy harvesting techniques, electrostatic-based power generation is attractive as it can be integrated using mainstream silicon technologies while providing higher power densities through miniaturization. However the power output of reported electrostatic micro-generators to date does not meet the communication and computation requirements of wireless sensor nodes. The objective of this thesis is to investigate novel CMOS-based energy harvesting circuit (EHC) architectures to increase the level of harvested mechanical energy in electrostatic converters. The electronic circuits that facilitate mechanical to electrical energy conversion employing variable capacitors can either have synchronous or asynchronous architectures. The later does not require synchronization of electrical events with mechanical motion, which eliminates difficulties in gate clocking and the power consumption associated with complex control circuitry. However, the implementation of the EHC with the converter can be detrimental to system performance when done without concurrent optimization of both elements, an aspect mainly overlooked in the literature. System level analysis is performed to show that there is an optimum value for either the storage capacitor or cycle number for maximum scavenging of ambient energy. The analysis also shows that maximum power is extracted when the system approaches synchronous operation. However, there is a region of interest where the storage capacitor can be optimized to produce almost 70% of the ideal power taken as the power harvested with synchronous converters when neglecting the power consumption associated with synchronizing control circuitry. Theoretical predictions are confirmed by measurements on an asynchronous EHC implemented with a macro-scale electrostatic converter prototype. Based on the preceding analysis, the design of a novel ultra low power electrostatic integrated energy harvesting circuit is proposed for efficient harvesting of mechanical energy. The fundamental challenges of designing reliable low power sensing circuits for charge constrained electrostatic energy harvesters with capacity to self power its controller and driver stages are addressed. Experimental results are presented for a controller design implemented in AMI 0.7muM high voltage CMOS process using a macro-scale electrostatic converter prototype. The EHC produces 1.126muW for a power investment of 417nW with combined conduction and controller losses of 450nW which is a 20-30% improvement compared to prior art on electrostatic EHCs operating under charge constrain. Inherently dual plate variable capacitors harvest energy only during half of the mechanical cycle with the other half unutilized for energy conversion. To harvest mechanical energy over the complete mechanical vibration cycle, a low power energy harvesting circuit (EHC) that performs charge constrained synchronous energy conversion on a tri-plate variable capacitor for maximizing energy conversion is proposed. The tri-plate macro electrostatic generator with capacitor variation of 405pF to 1.15nF and 405pF to 1.07nF on two complementary adjacent capacitors is fabricated and used in the characterization of the designed EHC. The integrated circuit fabricated in AMI 0.7muM high voltage CMOS process, produces a total output power of 497nW to a 10muF reservoir capacitor from a 98Hz vibration signal. In summary, the thesis lays out the theoretical and experimental foundation for overcoming the main challenges associated with the desi

Kempitiya, Asantha

224

Bluff Body Fluid Interactions Modelling for Micro Energy Harvesting Application  

NASA Astrophysics Data System (ADS)

In this paper, we have presented a MEMS-based piezoelectric fluid-flow based micro energy harvester. The design and modelling of the energy harvester structure was based on a piezoelectric cantilever affixed to a bluff-body. In a cross fluid flow, pressure in the flow channel, in the wake of the bluff body, fluctuates with the same frequency as the pressure variation caused by the Kármán Vortex Street. This fluctuation of pressure in the flow channel causes the piezoelectric cantilever, trailing the bluff-body, to vibrate in a direction normal to the fluid flow direction. COMSOL finite element analysis software are used for the evaluation of various mechanical analysis of the micro energy harvester structure like, physical the Stress and Strain state in the cantilever structures, Eigen frequency Analysis, Transient analysis to demonstrate the feasibility of the design. Detailed steps of modelling and simulation results of the uniform cantilever were explained. The results confirm the probability of the fluid flow based MEMS energy harvester.

Bhuyan, M. S.; Majlis, B. Y.; Othman, M.; Ali, Sawal H. Md; Kalaivani, C.; Islam, S.

2013-04-01

225

The research of energy harvesting system use in RFID tag  

NASA Astrophysics Data System (ADS)

With the decreasing power requirement of microelectronics, environmental energy sources can begin to replace batteries in the RFID tag. In this spirit, a novel resonate piezoelectric device is developed in the combined structure of SAW and FBAR which used for generating electrical power "parasitically" while the RFID tag is moving. The relationship of the different vibration mode to the power density of harvesting energy is analyzed and the relative merits and compromises are discussed. In the last, the suggestions are proposed for improvements and potential applications in the RFID.

Yu, Liyang; Yao, Guohua; Yang, Wang

2012-10-01

226

Harvesting traffic-induced vibrations for structural health monitoring of bridges  

NASA Astrophysics Data System (ADS)

This paper discusses the development and testing of a renewable energy source for powering wireless sensors used to monitor the structural health of bridges. Traditional power cables or battery replacement are excessively expensive or infeasible in this type of application. An inertial power generator has been developed that can harvest traffic-induced bridge vibrations. Vibrations on bridges have very low acceleration (0.1-0.5 m s-2), low frequency (2-30 Hz), and they are non-periodic. A novel parametric frequency-increased generator (PFIG) is developed to address these challenges. The fabricated device can generate a peak power of 57 µW and an average power of 2.3 µW from an input acceleration of 0.54 m s-2 at only 2 Hz. The generator is capable of operating over an unprecedentedly large acceleration (0.54-9.8 m s-2) and frequency range (up to 30 Hz) without any modifications or tuning. Its performance was tested along the length of a suspension bridge and it generated 0.5-0.75 µW of average power without manipulation during installation or tuning at each bridge location. A preliminary power conversion system has also been developed.

Galchev, T. V.; McCullagh, J.; Peterson, R. L.; Najafi, K.

2011-10-01

227

Fluid-dynamic renewable energy harvesting system  

US Patent & Trademark Office Database

The invention provides a fluid-dynamic renewable energy harvesting system which includes fluid-foil means for interfacing with a fluid current such as a water current or wind or both, and which includes energy harvesting means utilizing fluid current driven periodic motion of the fluid-foil means for capturing fluid-dynamic renewable energy and converting it into usable energy in a desired form such as electricity. The invention provides devices, methods and systems for harvesting renewable energy for small-scale, medium-scale and large-scale applications, to provide real and substantial benefits towards efficiently fulfilling energy needs while also more broadly serving humanity and our global environment. The various embodiments of the invention provide energy with zero consumption of fossil fuels and zero emissions of greenhouse gases, and some selectively sited embodiments can beneficially counter global warming induced ice melting.

Sankrithi; Mithra M. K. V. (Lake Forest Park, WA)

2010-07-06

228

Electromagnetic vibration harvester with piezoelectrically tunable resonance frequency  

NASA Astrophysics Data System (ADS)

This paper presents an electromagnetic vibration scavenger that exhibits a tunable eigenfrequency. By applying a static electrical field the eigenfrequency can be shifted. This feature is originated from exploiting the elastostriction of the utilized piezoelectric bimorph suspension. It is demonstrated that in the tuning operation mode more than 50 µW are scavenged continuously across the feasible frequency range of 20 Hz.

Wischke, M.; Masur, M.; Goldschmidtboeing, F.; Woias, P.

2010-03-01

229

Optimal design of piezoelectric materials and devices for energy harvesting  

NASA Astrophysics Data System (ADS)

Piezoelectric vibration energy harvesters (PVEHs) have received considerable attention as an enabling technology for self-powered wireless sensor networks. However, the biggest challenge with PVEHs has been their insufficient power generation for practical applications, which necessitates creative and disruptive materials and structure design on various scales. In this work, a model-based design study is performed that includes structural, materials, and device-level power optimizations of PVEHs. The optimization results help in understanding the behavior of the device performance, such as voltage and power, when the devices are optimized under various operating conditions, including input operating frequencies and mechanical damping. Furthermore, the optimization provides both an optimal device design scheme for power improvement and a better understanding of the correlation between the material property and the energy-harvesting output performance.

Kim, Miso; Dugundji, John; Wardle, Brian L.

2013-06-01

230

Optimizing the dielectric elastomer energy harvesting cycles  

Microsoft Academic Search

From an electrical point of view dielectric elastomers are variable capacitors, which are frequently used as generators. The focus of this paper is to show, how the maximum energy gain can be realized by realizing an innovative current waveform to charge and discharge the polymer. Several energy harvesting cycles are introduced and their energy output compared. The most promising cycle

Rick van Kessel; B. Czech; P. Bauer; J. A. Ferreira

2010-01-01

231

Energy-harvesting potential of multiple elastic structures in tandem arrangement  

NASA Astrophysics Data System (ADS)

Vortex-induced flapping vibrations of elastic structures attached with piezoelectric materials, i.e., ``piezo-leaves'', have recently been explored for its potential application in wind energy harvesting (e.g., Li, Yuan, and Lipson, J. Appl. Phys., 2011). In this work, we explore the possibility of enhancing the structural vibration and energy harvesting performance of the generator by putting the leaves in tandem arrangement and within close range of hydrodynamic interaction. A two-dimensional model is developed, where two or more elastic plates are mounted in a cross flow. In the case of two plates, the numerical simulation shows that at a particular distance, the vibration of the downstream plate is greatly increased, and so is the energy level of the entire system. For multiple plates, we observed both synchronized and apparently chaotic vibration modes. The characteristics of the vortex interaction, plate deformation, and energetics will be presented for those coupling modes.

Yin, Bo; Luo, Haoxiang

2011-11-01

232

Prototyping of Battery-less Wireless Sensor Node Using Electret-based Kinetic Energy Harvesting  

NASA Astrophysics Data System (ADS)

A battery-less wireless sensor node using a vibration-driven MEMS electret energy harvester has been prototyped. With hybrid high-aspect ratio parylene springs and high-performance electret material based on perfluoro polymer CYTOP, more than 3?W output power can be obtained in a broad range vibration frequency of 26-40 Hz at 1.4 G. By integrating the energy harvester with a power management circuit, low-power-consumption CPU, and RF IC, intermittent wireless transmission with an interval of 80.6 s has been realized.

Matsumoto, Koichi; Saruwatari, Kumio; Suzuki, Yuji

233

Energy harvesting from underwater base excitation of a piezoelectric composite beam  

NASA Astrophysics Data System (ADS)

In this paper, we investigate energy harvesting from underwater base excitation of a piezoelectric composite beam. Four different geometric configurations are experimentally studied in which the beam is either fully submerged or is partially immersed, with an eighth, a quarter, or a half of its length vibrating underwater. The frequency and the amplitude of base excitation are systematically varied along with the shunting resistance to investigate the principles of piezoelectric energy harvesting from underwater vibrations. Results demonstrate that increasing the wet length produces a consistent reduction of the resonance frequency and the quality factor of underwater vibrations. On the other hand, the harvested power is found to generally decrease as the submersion length is increased. Experimental results are interpreted through a distributed piezohydroelastic model that accounts for added mass and nonlinear hydrodynamic damping effects. A reduced order modal model is further established to parametrically explore the system response across a variety of geometrical and physical parameters.

Cha, Youngsu; Kim, Hubert; Porfiri, Maurizio

2013-11-01

234

Modeling and analysis of a biomorph piezoelectric energy harvester for railway bridge monitoring  

NASA Astrophysics Data System (ADS)

Wireless sensor network is one of prospective methods for railway bridge health monitoring. It has drawn much attention due to the long-term operation and low-maintenance performances. However, how to provide power to wireless sensors is a big issue. In railway health monitoring, the idea of converting ambient vibration energy from the vibration of railway track induced by passing train to electric energy has made it an efficient way for powering the wireless sensor networks. In this paper, a bimorph piezoelectric energy harvester from base excitation was investigated in the laboratory, and the energy output of the bimorph energy harvester was predicted by an equivalent single-degree-of-freedom (SDOF) model. Reasonable results have been found between the tested and predicted data. Based on the theoretical model, further works on optimization of the bimorph piezoelectric energy harvester will be performed in future.

Li, Jingcheng; Jang, Shinae; Tang, Jiong

2012-03-01

235

Vibrational energy transfer of very highly vibrationally excited NO  

NASA Astrophysics Data System (ADS)

The PUMP-DUMP-PROBE method has been used to study the collisional vibrational energy transfer dynamics of very highly vibrationally excited NO. At vibrational energies up to 3 eV, the qualitative trends observed in the experiments, such as the mass effect and the multiquantum relaxation, can be explained by the Schwartz-Slawsky-Herzfeld theory. A simple explanation is also given for the anomalously high NO self-relaxation rate observed in the experiments.

Yang, Xueming; Kim, Eun H.; Wodtke, Alec M.

1992-04-01

236

On the performance and resonant frequency of electromagnetic induction energy harvesters  

Microsoft Academic Search

This paper investigates the linear response of an archetypal energy harvester that uses electromagnetic induction to convert ambient vibration into electrical energy. In contrast with most prior works, the influence of the circuit inductance is not assumed negligible. Instead, we highlight parameter regimes where the inductance can alter resonance and derive an expression for the resonant frequency.The governing equations consider

B. P. Mann; N. D. Sims

2010-01-01

237

On the performance and resonant frequency of electromagnetic induction energy harvesters  

Microsoft Academic Search

This paper investigates the linear response of an archetypal energy harvester that uses electromagnetic induction to convert ambient vibration into electrical energy. In contrast with most prior works, the influence of the circuit inductance is not assumed negligible. Instead, we highlight parameter regimes where the inductance can alter resonance and derive an expression for the resonant frequency. The governing equations

B. P. Mann; N. D. Sims

2010-01-01

238

Energy harvesting from base excitation of ionic polymer metal composites in fluid environments  

Microsoft Academic Search

In this paper, we analytically and experimentally study the energy harvesting capability of submerged ionic polymer metal composites (IPMCs). We consider base excitation of an IPMC strip that is shunted with an electric impedance and immersed in a fluid environment. We develop a modeling framework to predict the energy scavenged from the IPMC vibration as a function of the excitation

Matteo Aureli; Chekema Prince; Maurizio Porfiri; Sean D. Peterson

2010-01-01

239

Elastically bounded flapping wing for energy harvesting  

NASA Astrophysics Data System (ADS)

In this Letter, we present and discuss an energy harvesting device, based on a wing elastically bounded to a fixed support. Large amplitude and periodic oscillations can be induced when this system is subject to wind, if a few parameters are carefully set. A linear stability analysis as well as two-dimensional numerical simulations confirms the existence of instability regions in the parameter space. In order to harvest energy by using this system, different methods are considered. Preliminary results obtained by an electromagnetic coupling are presented.

Boragno, C.; Festa, R.; Mazzino, A.

2012-06-01

240

Hybrid piezoelectric-inductive flow energy harvesting and dimensionless electroaeroelastic analysis for scaling  

NASA Astrophysics Data System (ADS)

Piezoelectric and electromagnetic transduction techniques have peculiar advantages to leverage in the growing field of flow energy harvesting from aeroelastic vibrations. This letter presents the concept of hybrid piezoelectric-inductive power generation with electroaeroelastic modeling and simulations. Dimensionless analysis of the coupled system dynamics is indispensable to proper geometric scaling and optimization of aeroelastic energy harvesters. The governing electroaeroelastic equations are given in dimensionless form, and the effects of aeroelastic and electrical properties are investigated in detail toward understanding the dependence of the cut-in speed (flutter speed) and the maximum power output of the harvester on the system parameters.

Dias, J. A. C.; De Marqui, C.; Erturk, A.

2013-01-01

241

Circuits for energy harvesting sensor signal processing  

Microsoft Academic Search

ducesystem weight andvolume, increase operating lifetime, Therecent explosion incapability ofembedded andportable decrease maintenance costs, andopennewfrontiers forin- electronics hasnotbeenmatchedbybattery technology. tegrating digital computation withsensing andactuation. Theslowgrowth ofbattery energy density haslimited device Because wireless communication typically consumes much lifetime andaddedweight andvolume. Passive energy har- morepowerthancomputation, manyapplications wantto vesting fromsolar radiation, thermal sources, ormechanicalmaximize theamountofcomputation doneataparticular vibration haspotentially wideapplication inwearable and sensor network

Rajeevan Amirtharajah; Justin Wenck; Jamie Collier; Jeff Siebert; Bicky Zhou

2006-01-01

242

Energy harvesting using semi-active control  

NASA Astrophysics Data System (ADS)

This paper presents the application of semi-active control for optimising the power harvested by an electro-mechanical energy harvester. A time-periodic damper, defined by a Fourier series, is introduced for energy harvesting in order to increase the performance of the device. An analytical solution for the transmissibility and the average absorbed power is derived based on the method of harmonic balance. The coefficients of the semi-active model are optimised to maximise the harvested power. The harvested power from the optimum periodic time-varying damper at a particular frequency is compared and is shown to be greater than that from an optimum passive damper and a semi-active on-off damper not only at that particular frequency but also at other frequencies. In addition, the performance of the optimised periodic time-varying damper is also compared with an arbitrary semi-active time-periodic damper, which has the same transmissibility at resonance. An optimisation is carried out to maximise the power in a frequency range and the optimum damper is derived as a function of the excitation frequency. The numerical results are validated with the analytical approach.

Di Monaco, Francesco; Ghandchi Tehrani, Maryam; Elliott, Stephen J.; Bonisoli, Elvio; Tornincasa, Stefano

2013-11-01

243

Integrated solar energy harvesting and storage  

Microsoft Academic Search

ABSTRACT To explore integrated solar energy harvesting as a power,source for low power systems such as wireless sensor nodes, an array of energy,scavenging ,photodiodes ,based ,on a ,passive-pixel architecture for imagers and have been fabricated together with storage capacitors implemented ,using on-chip interconnect in a 0.35 ?m CMOS ,logic process. Integrated vertical plate capacitors enable dense energy storage without limiting

Nathaniel J. Guilar; Albert Chen; Travis Kleeburg; Rajeevan Amirtharajah

2006-01-01

244

FR4-based electromagnetic energy harvester for wireless sensor nodes  

NASA Astrophysics Data System (ADS)

Electromagnetic (EM) energy harvesting seems to be one of the most promising ways to power wireless sensors in a wireless sensor network. In this paper, FR4, the most commonly used PCB material, is utilized as a mechanical vibrating structure for EM energy harvesting for body-worn sensors and intelligent tire sensors, which involve impact loadings. FR4 can be a better material for such applications compared to silicon MEMS devices due to lower stiffness and broadband response. In order to demonstrate FR4 performance and broadband response, three moving magnet type EM generator designs are developed and investigated throughout the paper. A velocity-damped harvester simulation model is first developed, including a detailed magnetic model and the magnetic damping effects. The numerical results agree well with the experimental results. Human running acceleration at the hip area that is obtained experimentally is simulated in order to demonstrate system performance, which results in a scavenged power of about 40 µW with 15 m s-2 acceleration input. The designed FR4 energy scavengers with mechanical stoppers implemented are particularly well suited for nearly periodic and non-sinusoidal high- g excitations with rich harmonic content. For the intelligent tire applications, a special compact FR4 scavenger is designed that is able to withstand large shocks and vibrations due to mechanical shock stoppers built into the structure. Using our design, 0.4 mW power across a load resistance at off-resonance operation is obtained in shaker experiments. In the actual operation, the tangential accelerations as a result of the tire-road contact are estimated to supply power around 1 mW with our design, which is sufficient for powering wireless tire sensors. The normalized power density (NPD) of the designed actuators compares favorably with most actuators reported in the literature.

Hatipoglu, G.; Ürey, H.

2010-01-01

245

Dielectric elastomer energy harvesting undergoing polarization saturation  

NASA Astrophysics Data System (ADS)

Mechanical energy can be converted into electrical energy by using a dielectric elastomer generator. The elastomer is susceptible to various models of failure, including electrical breakdown, electromechanical instability, loss of tension, and rupture by stretching. The models of failure define a cycle of maximal energy that can be converted. On the other hand, when subjected to voltage, the charge will be induced on a dielectric elastomer. When the voltage is small, the charge increases with the voltage. Along with the continuously increase of voltage, when the charge approaches a certain value, it would become saturated. This paper develops a thermodynamic model of dielectric elastomers undergoing polarization saturation. We studied the typical failure model with three variables of Gent Model silicone energy harvester and obtained an analytical solution of the constitutive equation of dielectric elastomer undergoing polarization saturation. These results can be used to facilitate the design and manufacture of dielectric elastomer energy harvesters.

Liu, Liwu; Luo, Xiaojian; Liu, Yanju; Leng, Jinsong

2012-03-01

246

On the self-powering of SHM techniques using seismic energy harvesting  

NASA Astrophysics Data System (ADS)

Growing demands in self-powered, wireless Structural Health Monitoring (SHM) systems has placed a particular attention on energy harvesting products. While most of works done in this domain considered directly coupled active materials, it may be preferential to use seismic (or indirect-coupled) harvesters for maintenance issues. With a seismic type harvester, a model considering constant vibration magnitude excitation is no longer valid as electrical energy extraction from mechanical vibration leads to a reduction of the vibration magnitude of the harvester because of electromechanical coupling effect. This paper extends a Single Degree of Freedom (SDOF) model with a constant force or acceleration excitation to a Two Degree of Freedom (TDOF) approach to describe the tradeoff between the damping effect on the host structure and the harvested power due to the mechanical to mechanical coupling effect. When the harvester mass to host structure mass ratio is around 10-3, the maximal power is obtained and the host structure has then a sudden displacement reduction due to the strong mechanical to mechanical coupling. Its application to self-powered SHM will be also introduced in the paper.

Wu, Yi-Chieh; Lallart, Mickaël.; Yan, Linjuan; Guyomar, Daniel; Richard, Claude

2013-04-01

247

Capacity of a Gaussian MAC with energy harvesting transmit nodes  

Microsoft Academic Search

We consider a Gaussian multiple access channel (GMAC) where the users are sensor nodes powered by energy harvesters. The energy harvesters may have finite or infinite buffer to store the harvested energy. First, we find the capacity region of a GMAC powered by transmit nodes with an infinite energy buffer. Next, we consider a GMAC with the transmitting nodes equipped

R. Rajesh; P. K. Deekshith; Vinod Sharma

2012-01-01

248

Toward energy harvesting using active materials and conversion improvement by nonlinear processing  

Microsoft Academic Search

This paper presents a new technique of electrical energy generation using mechanically excited piezoelectric materials and a nonlinear process. This technique, called synchronized switch harvesting (SSH), is derived from the synchronized switch damping (SSD), which is a nonlinear technique previously developed to address the problem of vibration damping on mechanical structures. This technique results in a significant increase of the

Daniel Guyomar; Adrien Badel; Elie Lefeuvre; Claude Richard

2005-01-01

249

The magnetic coupling of a piezoelectric cantilever for enhanced energy harvesting efficiency  

Microsoft Academic Search

It is shown that the energy harvesting capabilities of a piezoelectric cantilever can be enhanced through coupling to a static magnetic field. A permanent magnet is fixed to the end of a piezoelectric cantilever, causing it to experience a non-linear force as it moves with respect to a stationary magnet. The magnetically coupled cantilever responds to vibration over a much

Ji-Tzuoh Lin; Barclay Lee; Bruce Alphenaar

2010-01-01

250

Electroaeroelastic modeling and analysis of a hybrid piezoelectric-inductive flow energy harvester  

NASA Astrophysics Data System (ADS)

The conversion of aeroelastic vibrations into low-power electricity has received growing attention in the energy harvesting literature. Most of the existing research on wind energy harvesting has focused on transforming flow-induced vibrations into electricity by employing electromagnetic or piezoelectric transduction mechanisms separately. In this work, a hybrid airfoil-based aeroelastic energy harvester that simultaneously exploits piezoelectric transduction and electromagnetic induction is analyzed based on fully coupled electroaeroelastic modeling. Both forms of electromechanical coupling are introduced to the plunge degree of freedom. The interaction between total power generation (from piezoelectric transduction and electromagnetic induction) and the linear electroaeroelastic behavior of the typical section is investigated in the presence of two separate electrical loads. The effects of systems parameters, such as internal coil resistance, on the total power output and linear flutter speed are also discussed.

Dias, J. A. C.; De Marqui, C.; Erturk, Alper

2013-04-01

251

Energy-harvesting at the Nanoscale  

NASA Astrophysics Data System (ADS)

Energy harvesting is the process by which energy is taken from the environment and transformed to provide power for electronics. Specifically, the conversion of thermal energy into electrical power, or thermoelectrics, can play a crucial role in future developments of alternative sources of energy. Unfortunately, present thermoelectrics have low efficiency. Therefore, an important task in condensed matter physics is to find new ways to harvest ambient thermal energy, particularly at the smallest length scales where electronics operate. To achieve this goal, there is on one hand the miniaturizing of electrical devices, and on the other, the maximization of either efficiency or power the devices produce. We will present the theory of nano heat engines able to efficiently convert heat into electrical power. We propose a resonant tunneling quantum dot engine that can be operated either in the Carnot efficient mode, or maximal power mode. The ability to scale the power by putting many such engines in a ``Swiss cheese sandwich'' geometry gives a paradigmatic system for harvesting thermal energy at the nanoscale.

Jordan, Andrew; Sothmann, Björn; Sánchez, Rafael; Büttiker, Markus

2013-03-01

252

Nonlinear interface between the piezoelectric harvesting structure and the modulating circuit of an energy harvester with a real storage battery.  

PubMed

This paper studies the performance of an energy harvester with a piezoelectric bimorph (PB) and a real electrochemical battery (ECB), both are connected as an integrated system through a rectified dc-dc converter (DDC). A vibrating PB can scavenge energy from the operating environment by the electromechanical coupling. A DDC can effectively match the optimal output voltage of the harvesting structure to the battery voltage. To raise the output power density of PB, a synchronized switch harvesting inductor (SSHI) is used in parallel with the harvesting structure to reverse the voltage through charge transfer between the output electrodes at the transition moments from closed-to open-circuit. Voltage reversal results in earlier arrival of rectifier conduction because the output voltage phases of any two adjacent closed-circuit states are just opposite each other. In principle, a PB is with a smaller, flexural stiffness under closed-circuit condition than under open-circuit condition. Thus, the PB subjected to longer closed-circuit condition will be easier to be accelerated. A larger flexural velocity makes the PB to deflect with larger amplitude, which implies that more mechanical energy will be converted into an electric one. Nonlinear interface between the vibrating PB and the modulating circuit is analyzed in detail, and the effects of SSHI and DDC on the charging efficiency of the storage battery are researched numerically. It was found that the introduction of a DDC in the modulating circuit and an SSHI in the harvesting structure can raise the charging efficiency by several times. PMID:18334321

Hu, Yuantai; Xue, Huan; Hu, Ting; Hu, Hongping

2008-01-01

253

Effective energy harvesting devices for railroad applications  

NASA Astrophysics Data System (ADS)

The results of the design and development of a new generation of electromagnetic-based energy harvesting systems that can be readily installed in various vehicles are presented. The device resembles a conventional damper or shock absorber that is commonly used for vehicle suspensions. Such devices have received increased attention in the recent years with the much publicized development of GenShock by a group of MIT students. The device described in this study is different than the GenShock technology in that it does not use any fluid, is simpler, and can potentially provide a larger amount of electrical power. The presentation will provide a detailed description of the development of a prototype energy harvester, including the modeling and analysis of the electromagnetic components for increased efficiency. The laboratory test results of the prototype system indicate that more than 20 Watts of RMS energy can be realized at displacements and velocities that resemble the relative motion across a vehicle suspension.

Nagode, C.; Ahmadian, M.; Taheri, S.

2010-03-01

254

Design study of piezoelectric energy-harvesting devices for generation of higher electrical power using a coupled piezoelectric-circuit finite element method  

Microsoft Academic Search

This paper presents a design study on the geometric parameters of a cantilever-based piezoelectric energy-harvesting devices (EHD), which harvest energy from motion (vibration), for the purpose of scavenging more energy from ambient vibration energy sources. The design study is based on the coupled piezoelectric-circuit finite element method (CPCFEM), previously presented by Dr. Zhu. This model can calculate the power output

Meiling Zhu; Emma Worthington; Ashutosh Tiwari

2010-01-01

255

Design and power management of energy harvesting embedded systems  

Microsoft Academic Search

Harvesting energy from the environment is a desirable and increas- ingly important capability in several emerging applications of em- bedded systems such as sensor networks, biomedical implants, etc. While energy harvesting has the potential to enable near-perpetual system operation, designing an efficient energy harvesting system that actually realizes this potential requires an in-depth understand- ing of several complex tradeoffs. These

Vijay Raghunathan; Pai H. Chou

2006-01-01

256

Vibration energy scavenging via piezoelectric bimorphs of optimized shapes  

Microsoft Academic Search

Compact autonomous power sources are one of the prerequisites for the development of wireless sensor networks. In this work\\u000a vibration energy harvesting via piezoelectric resonant bimorph beams is studied. The available analytical approaches for the\\u000a modeling of the coupled electromechanical behavior are critically evaluated and compared with a finite element (FEM) numerical\\u000a model. The latter is applied to analyze thoroughly

Denis Benasciutti; Luciano Moro; Saša Zelenika; Eugenio Brusa

2010-01-01

257

A novel parametrically excited non-linear energy harvester  

NASA Astrophysics Data System (ADS)

In this study, a method utilizing parametrical resonance for harvesting energy from low-frequency vibrations was investigated. A pendulum-type architecture with electromagnetic induction as the energy conversion mechanism was proposed. A prototype device with a natural frequency of approximately 2 Hz was fabricated and evaluated experimentally. The performance of the device was studied theoretically and numerically. The results were validated by experiments. It was found that the numerical results were consistent with the experimental measurements, while the theoretical analysis slightly overestimated the power output. In the cases considered, the proposed device demonstrated qualitatively different behaviors as compared to a conventional linear device. Such difference, e.g. broadened bandwidth and increased power output at higher damping levels, may be advantageous in certain applications.

Ma, Tian-Wei; Zhang, Hui; Xu, Ning-Shou

2012-04-01

258

Energy harvesting from base excitation of ionic polymer metal composites in fluid environments  

NASA Astrophysics Data System (ADS)

In this paper, we analytically and experimentally study the energy harvesting capability of submerged ionic polymer metal composites (IPMCs). We consider base excitation of an IPMC strip that is shunted with an electric impedance and immersed in a fluid environment. We develop a modeling framework to predict the energy scavenged from the IPMC vibration as a function of the excitation frequency range, the constitutive and geometric properties of the IPMC, and the electric shunting load. The mechanical vibration of the IPMC strip is modeled through Kirchhoff-Love plate theory. The effect of the encompassing fluid on the IPMC vibration is described by using a linearized solution of the Navier-Stokes equations, that is traditionally considered in modeling atomic force microscope cantilevers. The dynamic chemo-electric response of the IPMC is described through the Poisson-Nernst-Planck model, in which the effect of mechanical deformations of the backbone polymer is accounted for. We present a closed-form solution for the current flowing through the IPMC strip as a function of the voltage across its electrodes and its deformation. We use modal analysis to establish a handleable expression for the power harvested from the vibrating IPMC and to optimize the shunting impedance for maximum energy harvesting. We validate theoretical findings through experiments conducted on IPMC strips vibrating in aqueous environments.

Aureli, Matteo; Prince, Chekema; Porfiri, Maurizio; Peterson, Sean D.

2010-01-01

259

Consideration of impedance matching techniques for efficient piezoelectric energy harvesting.  

PubMed

This study investigates multiple levels of impedance-matching methods for piezoelectric energy harvesting in order to enhance the conversion of mechanical to electrical energy. First, the transduction rate was improved by using a high piezoelectric voltage constant (g) ceramic material having a magnitude of g33 = 40 x 10(-3) V m/N. Second, a transducer structure, cymbal, was optimized and fabricated to match the mechanical impedance of vibration source to that of the piezoelectric transducer. The cymbal transducer was found to exhibit approximately 40 times higher effective strain coefficient than the piezoelectric ceramics. Third, the electrical impedance matching for the energy harvesting circuit was considered to allow the transfer of generated power to a storage media. It was found that, by using the 10-layer ceramics instead of the single layer, the output current can be increased by 10 times, and the output load can be reduced by 40 times. Furthermore, by using the multilayer ceramics the output power was found to increase by 100%. A direct current (DC)-DC buck converter was fabricated to transfer the accumulated electrical energy in a capacitor to a lower output load. The converter was optimized such that it required less than 5 mW for operation. PMID:17941391

Kim, Hyeoungwoo; Priya, Shashank; Stephanou, Harry; Uchino, Kenji

2007-09-01

260

Vibrational structure theory: new vibrational wave function methods for calculation of anharmonic vibrational energies and vibrational contributions to molecular properties.  

PubMed

A number of recently developed theoretical methods for the calculation of vibrational energies and wave functions are reviewed. Methods for constructing the appropriate quantum mechanical Hamilton operator are briefly described before reviewing a particular branch of theoretical methods for solving the nuclear Schrödinger equation. The main focus is on wave function methods using the vibrational self-consistent field (VSCF) as starting point, and includes vibrational configuration interaction (VCI), vibrational Møller-Plesset (VMP) theory, and vibrational coupled cluster (VCC) theory. The convergence of the different methods towards the full vibrational configuration interaction (FVCI) result is discussed. Finally, newly developed vibrational response methods for calculation of vibrational contributions to properties, energies, and transition probabilities are discussed. PMID:17551617

Christiansen, Ove

2007-03-23

261

Power Management for Energy Harvesting Wireless Sensors  

Microsoft Academic Search

The objective of this work was to demonstrate smart wireless sensing nodes capable of operation at extremely low power levels. These systems were designed to be compatible with energy harvesting systems using piezoelectric materials and\\/or solar cells. The wireless sensing nodes included a microprocessor, on-board memory, sensing means (1000 ohm foil strain gauge), sensor signal conditioning, 2.4 GHz IEEE 802.15.4

S. W. Arms; C. P. Townsend; D. L. Churchill; J. H. Galbreath; S. W. Mundell

2005-01-01

262

Strain Energy Harvesting for Wireless Sensor Networks  

Microsoft Academic Search

Our goal was to demonstrate a robust strain energy harvesting system for powering an embedded wireless sensor network without batteries. A composite material specimen was laminated with unidirectional aligned piezoelectric fibers (PZT5A, 250 um, overall 13x10x.38 mm). The fibers were embedded within a resin matrix for damage tolerance (Advanced Cerametrics, Lambertville, NJ). A foil strain gauge (Micro-Measurements, Raleigh, NC) was

D. L. Churchill; M. J. Hamel; C. P. Townsend; S. W. Arms

2003-01-01

263

Power management for energy harvesting wireless sensors  

Microsoft Academic Search

The objective of this work was to demonstrate smart wireless sensing nodes capable of operation at extremely low power levels. These systems were designed to be compatible with energy harvesting systems using piezoelectric materials and\\/or solar cells. The wireless sensing nodes included a microprocessor, on-board memory, sensing means (1000 ohm foil strain gauge), sensor signal conditioning, 2.4 GHz IEEE 802.15.4

S. W. Arms; C. P. Townsend; D. L. Churchill; J. H. Galbreath; S. W. Mundell

2005-01-01

264

Development of a biomechanical energy harvester  

PubMed Central

Background Biomechanical energy harvesting–generating electricity from people during daily activities–is a promising alternative to batteries for powering increasingly sophisticated portable devices. We recently developed a wearable knee-mounted energy harvesting device that generated electricity during human walking. In this methods-focused paper, we explain the physiological principles that guided our design process and present a detailed description of our device design with an emphasis on new analyses. Methods Effectively harvesting energy from walking requires a small lightweight device that efficiently converts intermittent, bi-directional, low speed and high torque mechanical power to electricity, and selectively engages power generation to assist muscles in performing negative mechanical work. To achieve this, our device used a one-way clutch to transmit only knee extension motions, a spur gear transmission to amplify the angular speed, a brushless DC rotary magnetic generator to convert the mechanical power into electrical power, a control system to determine when to open and close the power generation circuit based on measurements of knee angle, and a customized orthopaedic knee brace to distribute the device reaction torque over a large leg surface area. Results The device selectively engaged power generation towards the end of swing extension, assisting knee flexor muscles by producing substantial flexion torque (6.4 Nm), and efficiently converted the input mechanical power into electricity (54.6%). Consequently, six subjects walking at 1.5 m/s generated 4.8 ± 0.8 W of electrical power with only a 5.0 ± 21 W increase in metabolic cost. Conclusion Biomechanical energy harvesting is capable of generating substantial amounts of electrical power from walking with little additional user effort making future versions of this technology particularly promising for charging portable medical devices.

Li, Qingguo; Naing, Veronica; Donelan, J Maxwell

2009-01-01

265

A wideband acoustic energy harvester using a three degree-of-freedom architecture  

NASA Astrophysics Data System (ADS)

In this study, an acoustic energy harvester consisting of a perforated brass plate sandwiched between two cavities is designed and fabricated for scavenging energy from wide-spectrum acoustic sources. The multi-mode resonances of the device are adjusted closely spaced over a wide range of frequencies by properly tuned acoustic coupling of the vibrating plate and the two cavities. The experimental results show that the proximity of the multiple peaks enables the harvester operating in the frequency range of 1100-1400 Hz, which provides useful leads for the realization of acoustic energy generators of practical interest.

Peng, Xiao; Wen, Yumei; Li, Ping; Yang, Aichao; Bai, Xiaoling

2013-10-01

266

Issues in mathematical modeling of piezoelectric energy harvesters  

Microsoft Academic Search

The idea of vibration-to-electric energy conversion for powering small electronic components by using the ambient vibration energy has been investigated by researchers from different disciplines in the last decade. Among the possible transduction mechanisms, piezoelectric transduction has received the most attention for converting ambient vibrations to useful electrical energy. In the last five years, there have been a considerable number

A. Erturk; D. J. Inman

2008-01-01

267

Harvest.  

National Technical Information Service (NTIS)

A study of the men, land and machines responsible for America's agriculture abundance. Depicts the farmer as living simply and working hard for his bountiful harvest. Discusses diversity of farming and harvesting techniques, transportation of produce, uni...

1994-01-01

268

Optimal energy management policies for energy harvesting sensor nodes  

Microsoft Academic Search

We study a sensor node with an energy harvesting source. The generated energy can be stored in a buffer. The sensor node periodically senses a random field and generates a packet. These packets are stored in a queue and transmitted using the energy available at that time. We obtain energy management policies that are throughput optimal, i.e., the data queue

Vinod Sharma; Utpal Mukherji; Vinay Joseph; Shrey Gupta

2010-01-01

269

An active piezoelectric energy extraction method for pressure energy harvesting  

Microsoft Academic Search

This paper presents an energy harvesting technique to power autonomous systems and more particularly active implantable medical devices. We employ a piezoelectric diaphragm placed in a fluidic environment such as blood subjected to very low frequency (2 Hz) pressure variations that is deflected in a quasi-static manner and transduces mechanical energy into electrical energy. In order to maximize energy generation

M Deterre; E Lefeuvre; E Dufour-Gergam

2012-01-01

270

The fundamental role of quantized vibrations in coherent light harvesting by cryptophyte algae.  

PubMed

The influence of fast vibrations on energy transfer and conversion in natural molecular aggregates is an issue of central interest. This article shows the important role of high-energy quantized vibrations and their non-equilibrium dynamics for energy transfer in photosynthetic systems with highly localized excitonic states. We consider the cryptophyte antennae protein phycoerythrin 545 and show that coupling to quantized vibrations, which are quasi-resonant with excitonic transitions is fundamental for biological function as it generates non-cascaded transport with rapid and wider spatial distribution of excitation energy. Our work also indicates that the non-equilibrium dynamics of such vibrations can manifest itself in ultrafast beating of both excitonic populations and coherences at room temperature, with time scales in agreement with those reported in experiments. Moreover, we show that mechanisms supporting coherent excitonic dynamics assist coupling to selected modes that channel energy to preferential sites in the complex. We therefore argue that, in the presence of strong coupling between electronic excitations and quantized vibrations, a concrete and important advantage of quantum coherent dynamics is precisely to tune resonances that promote fast and effective energy distribution. PMID:23145719

Kolli, Avinash; O'Reilly, Edward J; Scholes, Gregory D; Olaya-Castro, Alexandra

2012-11-01

271

MEMS electrostatic energy harvesters with end-stop effects  

NASA Astrophysics Data System (ADS)

In micro scale energy harvesting devices, end-stops that limit the proof mass motion are inevitable from reliability concerns and can even be exploited as a functional element to achieve a broadband response. To investigate how these can be modelled, both characterization and modelling of vibration energy harvesters with end-stop effects are presented in this paper. A Hertz contact model of the impact force between the proof mass and the end-stops is analysed and compared to a linear stiffness model. The resulting impact force model is then included into a SPICE model of an electrostatic harvester. The performance prediction of the model is validated by comparing simulations and measurements on two different prototypes, one with mechanical quality factor Qm = 5.7 and one with Qm = 203.5. The electromechanical coupling factors of the two devices are respectively k2 = 1.44% and 2.52%. Both devices display the well-known jump phenomenon and output voltage saturation during, respectively, frequency and amplitude sweeps. Under low-level broadband excitations, the high-Qm device performs in agreement with linear theory at an efficiency of 71.8%. For sufficiently high acceleration power spectral density (PSD), it displays a soft limit on the output power and a bandwidth increase, e.g. a factor 3.7 increase of 3 dB bandwidth when increasing the acceleration PSD from 0.34 × 10-3 to 0.55 × 10-3 g2 Hz-1. The end-stop effects reduce the device efficiency down to 35.4% at 1.69 × 10-3 g2 Hz-1. A comparison between model and experiment shows that a model with end-stop stiffness extracted from the contact analysis can adequately model the nonlinear end-stop effects both for narrow- and broadband accelerations.

Phu Le, Cuong; Halvorsen, Einar

2012-07-01

272

Designing maximum power output into piezoelectric energy harvesters  

NASA Astrophysics Data System (ADS)

Energy harvesting from vibrational sources has been the focus of extensive research in the last decade, but fundamental questions remain concerning the design of these harvesters. We consider a piezoelectric bimorph energy harvester and seek to translate design requirements, such as mass and target natural frequency, into beam dimensions that maximize power output. Our method centers around optimizing the thickness of the piezoelectric layers of a beam relative to the total beam thickness, otherwise known as the thickness ratio. This method uses approximations for the fundamental frequency and mode shape. This allows for the development of algebraic expressions for the modal parameters required for the prediction of power output. The resulting expression for power is fully defined by the fixed system level requirements and the only unknown parameters, the piezoelectric thickness ratio and the damping ratio. We show in an example case that, for typical damping ratio values, the ideal thickness ratio is not significantly affected by changes in the damping ratio. As such, the method requires a simple sweep of the thickness ratio in order to determine the beam design which maximizes the power. We develop the design method for both systems where the piezoelectric material is continuous and where the thickness is selected from a discrete set of values. Because our method produces a single algebraic expression for the power, the resulting beam design can be developed extremely quickly from a set of design requirements, and thus does not require optimization algorithms. We also show that our design method achieves more power output and requires less piezoelectric material than an approach which maximizes the coupling coefficient.

Shafer, Michael W.; Bryant, Matthew; Garcia, Ephrahim

2012-08-01

273

Tire tread deformation sensor and energy harvester development for smart-tire applications  

NASA Astrophysics Data System (ADS)

Pneumatic tires are critical components in mobile systems that are widely used in our lives for passenger and goods transportation. Wheel/ground interactions in these systems play an extremely important role for not only system design and efficiency but also safe operation. However, fully understanding wheel/ground interactions is challenging because of high complexity of such interactions and the lack of in situ sensors. In this paper, we present the development of a tire tread deformation sensor and energy harvester for real-time tire monitoring and control. Polyvinylidene fluoride (PVDF) based micro-sensor is designed and fabricated to embed inside the tire tread and to measure the tread deformation. We also present a cantilever array based energy harvester that takes advantages of the mechanical bandpass filter concept. The harvester design is able to have a natural frequency band that can be used to harvest energy from varying-frequency vibrational sources. The energy harvester is also built using with new single crystal relaxor ferroelectric material (1 - V)Pb(Mg1/3Nb2/3)O3-VPbTiO3 (PMN-PT) and interdigited (IDT) electrodes that can perform the energy conversion more efficiently. Some preliminary experiment results show that the performance of the sensor and the energy harvester is promising.

Moon, Kee S.; Liang, Hong; Yi, Jingang; Mika, Bartek

2007-05-01

274

Energy harvesting using a thermoelectric material  

DOEpatents

A novel energy harvesting system and method utilizing a thermoelectric having a material exhibiting a large thermally induced strain (TIS) due to a phase transformation and a material exhibiting a stress induced electric field is introduced. A material that exhibits such a phase transformation exhibits a large increase in the coefficient of thermal expansion over an incremental temperature range (typically several degrees Kelvin). When such a material is arranged in a geometric configuration, such as, for a example, a laminate with a material that exhibits a stress induced electric field (e.g. a piezoelectric material) the thermally induced strain is converted to an electric field.

Nersessian, Nersesse (Van Nuys, CA); Carman, Gregory P. (Los Angeles, CA); Radousky, Harry B. (San Leandro, CA)

2008-07-08

275

Solar Energy Harvesting for ZigBee Electronics  

Microsoft Academic Search

The use of environmental energy harvesting to increase the autonomy of wireless sensor networks has recently emerged as a\\u000a viable option to provide energy replacing batteries. This paper systematically analyzed the various design choices and tradeoffs\\u000a which are involved in the design of solar energy harvesting modules required to design an efficient solar energy harvesting\\u000a system. A prototype based on

Xin Lu; Shuang-Hua Yang

276

Energy wood harvesting productivity of three harvesting methods in first thinning of scots pine ( Pinus sylvestris L.)  

Microsoft Academic Search

Energy wood harvesting in young forests presents an economical challenge and has been dependent on subsidies in Finland. Whole-tree harvesting systems have proved to be most productive when carrying out energy wood harvesting in cleanings and early thinnings in young forests. The application of integrated energy wood and pulpwood harvesting is less common.It was hypothesized that multi-tree harvesting (MTH) with

Jani Lehtimäki; Juha Nurmi

2011-01-01

277

Nonlinear dynamics of a bistable piezoelectric-composite energy harvester for broadband application  

NASA Astrophysics Data System (ADS)

The continuing need for reduced power requirements for small electronic components, such as wireless sensor networks, has prompted renewed interest in recent years for energy harvesting technologies capable of capturing energy from ambient vibrations. A particular focus has been placed on piezoelectric materials and devices due to the simplicity of the mechanical to electrical energy conversion and their high strain energy densities compared to electrostatic and electromagnetic equivalents. In this paper an arrangement of piezoelectric layers attached to a bistable asymmetric laminate is investigated experimentally to understand the dynamic response of the structure and power generation characteristics. The inherent bistability of the underlying structure is exploited for energy harvesting since a transition from one stable configuration to another, or "snap-through", is used to repeatedly strain the surface bonded piezoelectric and generate electrical energy. This approach has been shown to exhibit high levels of power extraction over a wide range of vibrational frequencies. Using high speed digital image correlation, a variety of dynamic modes of oscillation are identified in the harvester. The sensitivity of such modes to changes in vibration frequency and amplitude are investigated. Power outputs are measured for repeatable snap-through events of the device and are correlated with the measured modes of oscillation. The typical power generated is approximately 3.2 mW, comparing well with the needs of typical wireless senor node applications.

Betts, D. N.; Bowen, C. R.; Kim, H. A.; Gathercole, N.; Clarke, C. T.; Inman, D. J.

2013-09-01

278

Prototyping circuit design for Dielectric Electroactive Polymers energy harvesting  

Microsoft Academic Search

Dielectric Electroactive Polymer (DEAP) is an emerging material for energy harvesting, which can converter mechanical energy to electrical energy. A DEAP energy harvesting system architecture has been designed and simulated in our previous work. In this paper, we designed and implemented a prototyping circuit which includes a 4-order active low pass filter and a storage circuit. Experimental results show that,

Peiwen He; Wei Wang; Ken Choi; JongHyun Lee; SooHyun Kim

2011-01-01

279

Design, fabrication, and testing of energy-harvesting thermoelectric generator  

NASA Astrophysics Data System (ADS)

An energy-harvesting thermoelectric generator (TEG) is being developed to provide power for wireless sensors used in health monitoring of Navy machinery. TEGs are solid-state devices that convert heat directly into electricity without any moving parts. In this application, the TEGs utilize the heat transfer between shipboard waste heat sources and the ambient air to generate electricity. In order to satisfy the required small design volume of less than one cubic inch, Hi-Z is using its innovative thin-film Quantum Well (QW) thermoelectric technology that will provide a factor of four increase in efficiency and a large reduction in the device volume over the currently used bulk Bi2Te3 based thermoelectics. QWs are nanostructured multi-layer films. These wireless sensors can be used to detect cracks, corrosion, impact damage, and temperature and vibration excursions as part of the Condition Based Maintenance (CBM) of the Navy ship machinery. The CBM of the ship machinery can be significantly improved by automating the process with the use of self-powered wireless sensors. These power-harvesting TEGs can be used to replace batteries as electrical power sources and to eliminate power cables and data lines. The first QW TEG module was fabricated and initial tests were successful. It is planned to conduct performance tests the entire prototype QW TEG device (consisting of the TEG module, housing, thermal insulation and the heat sink) in a simulated thermal environment of a Navy ship.

Jovanovic, Velimir; Ghamaty, Saeid

2006-04-01

280

Photoenergy Harvesting Organic PV Cells Using Modified Photosynthetic Light-Harvesting Complex for Energy Harvesting Materials.  

National Technical Information Service (NTIS)

The purpose of this research is to use modified photosynthetic light- harvesting (LH) complexes from modern biosynthetic manufacturing methods of purple photosynthetic bacteria in order to control the direction and orientation of the complex on electrodes...

M. Nango

2008-01-01

281

An optimized self-powered switching circuit for non-linear energy harvesting with low voltage output  

Microsoft Academic Search

Harvesting energy from environmental sources has been of particular interest these last few years. Microgenerators that can power electronic systems are a solution for the conception of autonomous, wireless devices. They allow the removal of bulky and costly wiring, as well as complex maintenance and environmental issues for battery-powered systems. In particular, using piezoelectric generators for converting vibrational energy to

Mickaël Lallart; Daniel Guyomar

2008-01-01

282

Performance modeling of unmanned aerial vehicles with on-board energy harvesting  

NASA Astrophysics Data System (ADS)

The concept of energy harvesting in unmanned aerial vehicles (UAVs) has received much attention in recent years. Solar powered flight of small aircraft dates back to the 1970s when the first fully solar flight of an unmanned aircraft took place. Currently, research has begun to investigate harvesting ambient vibration energy during the flight of UAVs. The authors have recently developed multifunctional piezoelectric self-charging structures in which piezoelectric devices are combined with thin-film lithium batteries and a substrate layer in order to simultaneously harvest energy, store energy, and carry structural load. When integrated into mass and volume critical applications, such as unmanned aircraft, multifunctional devices can provide great benefit over conventional harvesting systems. A critical aspect of integrating any energy harvesting system into a UAV, however, is the potential effect that the additional system has on the performance of the aircraft. Added mass and increased drag can significantly degrade the flight performance of an aircraft, therefore, it is important to ensure that the addition of an energy harvesting system does not adversely affect the efficiency of a host aircraft. In this work, a system level approach is taken to examine the effects of adding both solar and piezoelectric vibration harvesting to a UAV test platform. A formulation recently presented in the literature is applied to describe the changes to the flight endurance of a UAV based on the power available from added harvesters and the mass of the harvesters. Details of the derivation of the flight endurance model are reviewed and the formulation is applied to an EasyGlider remote control foam hobbyist airplane, which is selected as the test platform for this study. A theoretical study is performed in which the normalized change in flight endurance is calculated based on the addition of flexible thin-film solar panels to the upper surface of the wings, as well as the addition of flexible piezoelectric patches to the root of the wing spar. Experimental testing is also performed in which the wing spar of the EasyGlider aircraft is modified to include both Macro Fiber Composite and Piezoelectric Fiber Composite piezoelectric patches near the root of the wing and two thin-film solar panels are installed onto the upper wing surface to harvest vibration and solar energy during flight. Testing is performed in which the power output of the various harvesters is measured during flight. Results of the flight testing are used to update the model with accurate measures of the power available from the energy harvesting systems. Finally, the model is used to predict the potential benefits of adding multifunctional self-charging structures to the wing spar of the aircraft in order to harvest vibration energy during flight and provide a local power source for low-power sensors.

Anton, Steven R.; Inman, Daniel J.

2011-03-01

283

Piezoelectric Energy Harvesting with a Clamped Circular Plate: Analysis  

Microsoft Academic Search

Energy harvesting using piezoelectric materials is not a new concept, but its small generation capability has not been attractive for mass energy generation. For this reason, little research has been done on the topic. Recently, increased interest in wearable computer concepts and remote electrical devices has provided motivation for more extensive study of piezoelectric energy harvesting. The theory behind cantilever-type

Sunghwan Kim; William W. Clark; Qing-Ming Wang

2005-01-01

284

Prototype implementation of ambient RF energy harvesting wireless sensor networks  

Microsoft Academic Search

Energy harvesting is a key technique that can be used to overcome the barriers that prevent the real world deployment of wireless sensor networks (WSNs). In particular, solar energy harvesting has been commonly used to overcome this barrier. However, it should be noted that WSNs operating on solar power suffer form energy shortage during nighttimes. Therefore, to solve this problem,

Hiroshi Nishimoto; Yoshihiro Kawahara; Tohru Asami

2010-01-01

285

A comparison between nonlinear cantilever and buckled beam for energy harvesting  

NASA Astrophysics Data System (ADS)

Nonlinear dynamics has become one of the key aspect to improve the efficiency of kinetic energy harvesters working in the real environment. Different methods based on the exploitation of the dynamical features of stochastic nonlinear oscillators using bi-stable piezoelectric cantilevers or buckled beams have been proposed in the past years. Such methods are shown to outperform standard linear oscillators and to overcome some of the most severe limitations of present approaches once applied to ambient vibrations. This work presents simulation results comparing the two methods. The same piezoelectric element subjected to a fixed vibrating body in a cantilever or bridge configuration has been simulated. The kinetic excitation considered is a zero mean exponentially correlated gaussian noise with different amplitudes. The piezoelectric oscillator output response has been obtained as a function of a nonlinear parameter. This work is intended to help designing the most performing energy harvester for real world applications starting from the same piezoelectric element.

Vocca, H.; Cottone, F.; Neri, I.; Gammaitoni, L.

2013-09-01

286

Energy scavenging from environmental vibration.  

SciTech Connect

The goal of this project is to develop an efficient energy scavenger for converting ambient low-frequency vibrations into electrical power. In order to achieve this a novel inertial micro power generator architecture has been developed that utilizes the bi-stable motion of a mechanical mass to convert a broad range of low-frequency (< 30Hz), and large-deflection (>250 {micro}m) ambient vibrations into high-frequency electrical output energy. The generator incorporates a bi-stable mechanical structure to initiate high-frequency mechanical oscillations in an electromagnetic scavenger. This frequency up-conversion technique enhances the electromechanical coupling and increases the generated power. This architecture is called the Parametric Frequency Increased Generator (PFIG). Three generations of the device have been fabricated. It was first demonstrated using a larger bench-top prototype that had a functional volume of 3.7cm3. It generated a peak power of 558{micro}W and an average power of 39.5{micro}W at an input acceleration of 1g applied at 10 Hz. The performance of this device has still not been matched by any other reported work. It yielded the best power density and efficiency for any scavenger operating from low-frequency (<10Hz) vibrations. A second-generation device was then fabricated. It generated a peak power of 288{micro}W and an average power of 5.8{micro}W from an input acceleration of 9.8m/s{sup 2} at 10Hz. The device operates over a frequency range of 20Hz. The internal volume of the generator is 2.1cm{sup 3} (3.7cm{sup 3} including casing), half of a standard AA battery. Lastly, a piezoelectric version of the PFIG is currently being developed. This device clearly demonstrates one of the key features of the PFIG architecture, namely that it is suitable for MEMS integration, more so than resonant generators, by incorporating a brittle bulk piezoelectric ceramic. This is the first micro-scale piezoelectric generator capable of <10Hz operation. The fabricated device currently generates a peak power of 25.9{micro}W and an average power of 1.21{micro}W from an input acceleration of 9.8m/s{sup -} at 10Hz. The device operates over a frequency range of 23Hz. The internal volume of the generator is 1.2cm{sup 3}.

Galchev, Tzeno (University of Michigan); Apblett, Christopher Alan; Najafi, Khalil (University of Michigan)

2009-10-01

287

Vibrational structure theory: new vibrational wave function methods for calculation of anharmonic vibrational energies and vibrational contributions to molecular properties  

Microsoft Academic Search

A number of recently developed theoretical methods for the calculation of vibrational energies and wave functions are reviewed. Methods for constructing the appropriate quantum mechanical Hamilton operator are briefly described before reviewing a particular branch of theoretical methods for solving the nuclear Schrodinger equation. The main focus is on wave function methods using the vibrational self-consistent field (VSCF) as starting

Ove Christiansen

2007-01-01

288

Simulation for energy harvesting system based on Dielectric Electro Active Polymers  

Microsoft Academic Search

Dielectric Electro Active Polymer (DEAP) is a new material for energy harvesting based on mechanical-to-electric energy conversion. In this paper, by using Matlab simulation, we prove that the original simple DEAP energy harvesting system cannot actually harvest energy. Then, a new system design based on DEAP is proposed to harvest energy. In the proposed system, the energy harvesting and feedback

Peiwen He; Feng Ge; Wei Wang; Ken Choi; Gyungsoo Kang; SooHyun Kim

2011-01-01

289

Optimized piezoelectric energy harvesting circuit using step-down converter in discontinuous conduction mode  

Microsoft Academic Search

An optimized method of harvesting vibrational energy with a piezoelectric element using a step-down DC-DC converter is presented. In this configuration, the converter regulates the power flow from the piezoelectric element to the desired electronic load. Analysis of the converter in discontinuous current conduction mode results in an expression for the duty cycle-power relationship. Using parameters of the mechanical system,

Geffrey K. Ottman; Heath F. Hofmann; George A. Lesieutre

2003-01-01

290

MEMS based pyroelectric thermal energy harvester  

DOEpatents

A pyroelectric thermal energy harvesting apparatus for generating an electric current includes a cantilevered layered pyroelectric capacitor extending between a first surface and a second surface, where the first surface includes a temperature difference from the second surface. The layered pyroelectric capacitor includes a conductive, bimetal top electrode layer, an intermediate pyroelectric dielectric layer and a conductive bottom electrode layer. In addition, a pair of proof masses is affixed at a distal end of the layered pyroelectric capacitor to face the first surface and the second surface, wherein the proof masses oscillate between the first surface and the second surface such that a pyroelectric current is generated in the pyroelectric capacitor due to temperature cycling when the proof masses alternately contact the first surface and the second surface.

Hunter, Scott R; Datskos, Panagiotis G

2013-08-27

291

The experimental validation of a new energy harvesting system based on the wake galloping phenomenon  

NASA Astrophysics Data System (ADS)

In this paper, a new energy harvesting system based on wind energy is investigated. To this end, the characteristics and mechanisms of various aerodynamic instability phenomena are first examined and the most appropriate one (i.e. wake galloping) is selected. Then, a wind tunnel test is carried out in order to understand the occurrence conditions of the wake galloping phenomenon more clearly. Based on the test results, a prototype electromagnetic energy harvesting device is designed and manufactured. The effectiveness of the proposed energy harvesting system is extensively examined via a series of wind tunnel tests with the prototype device. Test results show that electricity of about 370 mW can be generated under a wind speed of 4.5 m s - 1 by the proposed energy harvesting device. The generated power can easily be increased by simply increasing the number of electromagnetic parts in a vibrating structure. Also, the possibility of civil engineering applications is discussed. It is concluded from the test results and discussion that the proposed device is an efficient, economic and reliable energy harvesting system and could be applied to civil engineering structures.

Jung, Hyung-Jo; Lee, Seung-Woo

2011-05-01

292

Energy Harvesting for Structural Health Monitoring Sensor Networks  

Microsoft Academic Search

This paper reviews the development of energy harvesting for low-power embedded structural health monitoring (SHM) sensing systems. A statistical pattern recognition paradigm for SHM is first presented and the concept of energy harvesting for embedded sensing systems is addressed with respect to the data acquisition portion of this paradigm. Next, various existing and emerging sensing modalities used for SHM and

Tajana Rosing; Michael D. Todd; Charles R. Farrar; William Hodgkiss

2008-01-01

293

Design considerations for solar energy harvesting wireless embedded systems  

Microsoft Academic Search

Sustainable operation of battery powered wireless embed- ded systems (such as sensor nodes) is a key challenge, and considerable research effort has been devoted to energy optimization of such systems. Environmental energy harvesting, in particular solar based, has emerged as a viable technique to supplement battery supplies. However, designing an efficient solar harvesting system to realize the potential benefits of

Vijay Raghunathan; Aman Kansal; Jason Hsu; Jonathan Friedman; Mani B. Srivastava

2005-01-01

294

Efficient solar energy harvester for wireless sensor nodes  

Microsoft Academic Search

An efficient solar energy harvester for low power wireless sensor node is proposed in this paper. In the proposed harvester, maximum power point tracking (MPPT) is achieved by using constant voltage tracking principle. The implementation of the MPPT control circuit is carried out using analog discrete components. This is to minimize the energy consumption in the electronic circuits. Experimental test

Ko Ko Win; Xinhui Wu; Souvik Dasgupta; Wong Jun Wen; Rajesh Kumar; S. K. Panda

2010-01-01

295

Characterization of a rotary piezoelectric energy harvester based on plucking excitation for knee-joint wearable applications  

NASA Astrophysics Data System (ADS)

Wearable medical and electronic devices demand a similarly wearable electrical power supply. Human-based piezoelectric energy harvesters may be the solution, but the mismatch between the typical frequencies of human activities and the optimal operating frequencies of piezoelectric generators calls for the implementation of a frequency up-conversion technique. A rotary piezoelectric energy harvester designed to be attached to the knee-joint is here implemented and characterized. The wearable harvester is based on the plucking method of frequency up-conversion, where a piezoelectric bimorph is deflected by a plectrum and permitted to vibrate unhindered upon release. Experiments were conducted to characterize the energy produced by the rotary piezoelectric energy harvester with different electric loads and different excitation speeds, covering the range between 0.1 and 1 rev s-1 to simulate human gait speeds. The electrical loads were connected to the generator either directly or through a rectifying bridge, as would be found in most power management circuits. The focus of the paper is to study the capability of energy generation of the harvester for knee-joint wearable applications, and study the effects of the different loads and different excitation speeds. It is found that the energy harvested is around 160-490 µJ and strongly depends on the angular speed, the connected electric loads and also the manufacturing quality of the harvester. Statistical analysis is used to predict the potential energy production of a harvester manufactured to tighter tolerances than the one presented here.

Pozzi, Michele; Zhu, Meiling

2012-05-01

296

Optimal energy management over solar based energy harvesting sensor network  

Microsoft Academic Search

In this paper, we build a framework for maximizing the utilization of solar-based harvesting energy in sensor networks. For this goal, we analyze the required power at each relay node and give the queueing framework for the power management. In the simulation, our proposed algorithm shows a superior performance than conventional ones in terms of the PRR (Packet Reception Rate)

S. Lee; T. Kim; H. Son

2010-01-01

297

Energy harvesting in the nonlinear two-masses piezoelastic system driven by harmonic excitations  

NASA Astrophysics Data System (ADS)

We examine the energy harvesting system consisted of two different masses (magnets) attached to piezoelastic oscillators, coupled by the electric circuit, and driven by harmonic excitations. The nonlinearity of the system is achieved by variable distance between vibrating magnetic masses and the magnets attached directly to the harvester. We also introduce the mistuning parameter which describes the disproportion of vibrating masses (their ratio). In our work we examine the dependence of output power (in terms of mean squared voltage) generated on electric load on excitation frequencies for different values of mistuning parameter and additionally for different values of system nonlinearity parameter. We compare obtained results with the dia- grams presenting relative displacements of these oscillators (in terms of standard deviation) vs. excitation frequencies. In the second part of this paper we present the phase boundary lines (phase portraits) for selected values of applied frequency to show the complicated behavior of the oscillators in the nonlinear regime when the mistuning appears.

Kucab, K.; Górski, G.; Mizia, J.

2013-09-01

298

Impedance adaptation methods of the piezoelectric energy harvesting  

NASA Astrophysics Data System (ADS)

In this study, the important issues of energy recovery were addressed and a comprehensive investigation was performed on harvesting electrical power from an ambient mechanical vibration source. Also discussed are the impedance matching methods used to increase the efficiency of energy transfer from the environment to the application. Initially, the mechanical impedance matching method was investigated to increase mechanical energy transferred to the transducer from the environment. This was done by reducing the mechanical impedance such as damping factor and energy reflection ratio. The vibration source and the transducer were modeled by a two-degree-of-freedom dynamic system with mass, spring constant, and damper. The transmissibility employed to show how much mechanical energy that was transferred in this system was affected by the damping ratio and the stiffness of elastic materials. The mechanical impedance of the system was described by electrical system using analogy between the two systems in order to simply the total mechanical impedance. Secondly, the transduction rate of mechanical energy to electrical energy was improved by using a PZT material which has a high figure of merit and a high electromechanical coupling factor for electrical power generation, and a piezoelectric transducer which has a high transduction rate was designed and fabricated. The high g material (g33 = 40 [10-3Vm/N]) was developed to improve the figure of merit of the PZT ceramics. The cymbal composite transducer has been found as a promising structure for piezoelectric energy harvesting under high force at cyclic conditions (10--200 Hz), because it has almost 40 times higher effective strain coefficient than PZT ceramics. The endcap of cymbal also enhances the endurance of the ceramic to sustain ac load along with stress amplification. In addition, a macro fiber composite (MFC) was employed as a strain component because of its flexibility and the high electromechanical coupling factor. This characteristic is useful for a small force vibration source which has a high displacement such as human's activities. An experimental setup was used to apply the same conditions as a vibrating car engine. The experiment was done with a cymbal transducer which has 29 mm PZT diameter, 1mm PZT thickness, and 0.4mm endcap operating under force of 70 N in the frequency range of 10--200 Hz. It was found that the generated power was increased and the output impedance was decreased with a higher frequency of vibration source at a constant force. The experimental results were found to be in agreement with the analytical results from the model using the equivalent circuit. In addition, the FEM simulation (ATILA) was employed to optimize the dimensions of cymbal transducer such as endcap thickness and PZT thickness. Finally, the electrical impedance matching method used to increase the electrical to electrical energy transfer for some applications was discussed. To match the output impedance, two methods were employed: one is changing capacitance of transducer by size effect and multilayered ceramics, and another one is developing an energy harvesting circuit which consumes low electrical power and maximizes the output transferred to the intended load. The fabricated multilayered ceramics which has 10, 100 mum thick, layers yielded 10 times higher output current for 40 times reduced output load. Also the electrical output power was double. A DC-DC buck converter which has 78% efficiency was fabricated to transfer the accumulated electrical energy to the low output load without consuming more than 5 mW of power itself. In this DC-DC converter, most of the power was consumed by the gate drive which was required for PWM switching. To reduce the power consumption of the gate drive, the switching frequency was fixed at 1 kHz with optimal duty cycle around 1˜5%. Also the dependence of the inductance (L) in the DC-DC converter was investigated and optimized to increase the output power transferred to the small output load. Using this optimized DC-DC converter, two circ

Kim, Hyeoungwoo

299

Harvesting and Transport of Forestry Biomass for Energy Purposes.  

National Technical Information Service (NTIS)

In the project whole-tree utilization (PHU) a survey of the possibilities of harvesting and transporting wood for energy purposes has been considered essential. The types of raw-material taken into consideration come from energy forests, logging residue, ...

S. Andersson Y. Jonsson M. Nylinder

1977-01-01

300

Control of Vibratory Energy Harvesters in the Presence of Nonlinearities and Power-Flow Constraints  

NASA Astrophysics Data System (ADS)

Over the past decade, a significant amount of research activity has been devoted to developing electromechanical systems that can convert ambient mechanical vibrations into usable electric power. Such systems, referred to as vibratory energy harvesters, have a number of useful of applications, ranging in scale from self-powered wireless sensors for structural health monitoring in bridges and buildings to energy harvesting from ocean waves. One of the most challenging aspects of this technology concerns the efficient extraction and transmission of power from transducer to storage. Maximizing the rate of power extraction from vibratory energy harvesters is further complicated by the stochastic nature of the disturbance. The primary purpose of this dissertation is to develop feedback control algorithms which optimize the average power generated from stochastically-excited vibratory energy harvesters. This dissertation will illustrate the performance of various controllers using two vibratory energy harvesting systems: an electromagnetic transducer embedded within a flexible structure, and a piezoelectric bimorph cantilever beam. Compared with piezoelectric systems, large-scale electromagnetic systems have received much less attention in the literature despite their ability to generate power at the watt--kilowatt scale. Motivated by this observation, the first part of this dissertation focuses on developing an experimentally validated predictive model of an actively controlled electromagnetic transducer. Following this experimental analysis, linear-quadratic-Gaussian control theory is used to compute unconstrained state feedback controllers for two ideal vibratory energy harvesting systems. This theory is then augmented to account for competing objectives, nonlinearities in the harvester dynamics, and non-quadratic transmission loss models in the electronics. In many vibratory energy harvesting applications, employing a bi-directional power electronic drive to actively control the harvester is infeasible due to the high levels of parasitic power required to operate the drive. For the case where a single-directional drive is used, a constraint on the directionality of power-flow is imposed on the system, which necessitates the use of nonlinear feedback. As such, a sub-optimal controller for power-flow-constrained vibratory energy harvesters is presented, which is analytically guaranteed to outperform the optimal static admittance controller. Finally, the last section of this dissertation explores a numerical approach to compute optimal discretized control manifolds for systems with power-flow constraints. Unlike the sub-optimal nonlinear controller, the numerical controller satisfies the necessary conditions for optimality by solving the stochastic Hamilton-Jacobi equation.

Cassidy, Ian L.

301

Optimization of an Electromagnetic Energy Harvesting Device  

Microsoft Academic Search

This paper presents the modeling and optimization of an electromagnetic-based generator for generating power from ambient vibrations. Basic equations describing such generators are presented and the conditions for maximum power generation are described. Two-centimeter scale prototype generators, which consist of magnets suspended on a beam vibrating relative to a coil, have been built and tested. The measured power and modeled

Chitta Ranjan Saha; Terence O'Donnell; Heiko Loder; Steve Beeby; John Tudor

2006-01-01

302

Resistor Emulation Approach to Low-Power Energy Harvesting  

Microsoft Academic Search

This paper presents an approach and associated circuitry for harvesting near maximum output from low power sources in the 100 muW range for miniature wireless devices. A set of converter topologies and control approaches are presented together with detailed efficiency analysis and a design example for a buck-boost based energy harvesting converter using commercially available discrete circuitry. Experimental results are

Thurein S. Paing; Regan Zane

2006-01-01

303

Comparison of the dielectric electroactive polymer generator energy harvesting cycles  

NASA Astrophysics Data System (ADS)

The Dielectric ElectroActive Polymer (DEAP) generator energy harvesting cycles have been in the spotlight of the scientific interest for the past few years. Indeed, several articles have demonstrated thorough and comprehensive comparisons of the generator fundamental energy harvesting cycles, namely Constant Charge (CC), Constant Voltage (CV) and Constant E-field (CE), based on average theoretical models. Yet, it has not been possible until present to validate the outcome of those comparisons via respective experimental results. In this paper, all three primary energy harvesting cycles are experimentally compared, based upon the coupling of a DEAP generator with a bidirectional non-isolated power electronic converter, by means of energy gain, energy harvesting efficiency and energy conversion efficiency.

Dimopoulos, Emmanouil; Trintis, Ionut; Munk-Nielsen, Stig

2013-04-01

304

Piezoelectric and electromagnetic respiratory effort energy harvesters.  

PubMed

The movements of the torso due to normal breathing could be harvested as an alternative, and renewable power source for an ultra-low power electronic device. The same output signal could also be recorded as a physiological signal containing information about breathing, thus enabling self-powered wearable biosensors/harvesters. In this paper, the selection criteria for such a biosensor, optimization procedure, trade-offs, and challenges as a sensor and harvester are presented. The empirical data obtained from testing different modules on a mechanical torso and a human subject demonstrated that an electromagnetic generator could be used as an unobtrusive self-powered medical sensor by harvesting more power, offering reasonable amount of output voltage for rectification purposes, and detecting respiratory effort. PMID:24110468

Shahhaidar, Ehsaneh; Padasdao, Bryson; Romine, R; Stickley, C; Boric-Lubecke, Olga

2013-07-01

305

Apparatus for harvesting energy from flow-induced oscillations and method for the same  

US Patent & Trademark Office Database

A device and method for harvesting electrical power from kinetic energy of a flow. The electricity generator includes a vibration assembly and magnetic field source. The external gas or liquid flow causes a vibration of the assembly with an integrated conductive element, producing electricity in proximity of a magnetic field. The vibrating assembly has a set of resonant frequencies that correspond to a set of the frequencies of the flow vortices within a predetermined range of the external flow velocities. An arbitrary number of adjustable generators can be connected into a single circuit, either in-series or in-parallel, to increase an overall power output. It is capable to operate under wide range of flow characteristics and can serve as a virtually maintenance-free source of electrical power.

2012-09-04

306

Energy harvesting based on piezoelectric Ericsson cycles in a piezoceramic material  

NASA Astrophysics Data System (ADS)

The possibility of recycling ambient energies with electric generators instead of using batteries with limited life spans has stimulated important research efforts over the past years. The integration of such generators into mainly autonomous low-power systems, for various industrial or domestic applications is envisioned. In particular, the present work deals with energy harvesting from mechanical vibrations. It is shown here that direct piezoelectric energy harvesting (short circuiting on an adapted resistance, for example) leads to relatively weak energy levels that are insufficient for an industrial development. By coupling an electric field and mechanical excitation on Ericsson-based cycles, the amplitude of the harvested energy can be highly increased, and can reach a maximum close to 100 times its initial value. To obtain such a gain, one needs to employ high electrical field levels (high amplitude, high frequency), which induce a non-linearity through the piezoceramic. A special dynamic hysteresis model has been developed to correctly take into account the material properties, and to provide a real estimation of the harvested energy. A large number of theoretical predictions and experimental results have been compared and are discussed herein, in order to validate the proposed solution.

Zhang, B.; Ducharne, B.; Guyomar, D.; Sebald, G.

2013-09-01

307

Autonomous energy harvesting embedded sensors for border security applications  

NASA Astrophysics Data System (ADS)

Wireless networks of seismic sensors have proven to be a valuable tool for providing security forces with intrusion alerts even in densely forested areas. The cost of replenishing the power source is one of the primary obstacles preventing the widespread use of wireless sensors for passive barrier protection. This paper focuses on making use of energy from multiple sources to power these sensors. A system comprising of Texas Micropower's (TMP's) energy harvesting device and Crane Wireless Monitoring Solutions' sensor nodes is described. The energy harvesters are suitable for integration and for low cost, high volume production. The harvesters are used for powering sensors in Crane's wireless hub and spoke type sensor network. TMP's energy harvesting methodology is based on adaptive power management circuits that allow harvesting from multiple sources making them suitable for underground sensing/monitoring applications. The combined self-powered energy harvesting solutions are expected to be suitable for broad range of defense and industry applications. Preliminary results have indicated good feasibility to use a single power management solution that allows multi-source energy harvesting making such systems practical in remote sensing applications.

Hande, Abhiman; Shah, Pradeep; Falasco, James N.; Weiner, Doug

2010-04-01

308

Embedded fragmentation of vibrational energies.  

PubMed

Can the zero-point vibrational energies (ZPVE) of molecular clusters and crystals be evaluated as sums of ZPVE of constituent molecular fragments embedded in the cluster or crystal electrostatic environment? What is the appropriate unit of fragmentation: monomers or overlapping dimers? Can the contributions of acoustic phonons, which are fundamentally delocalized, be recuperated at satisfactory accuracy? These questions are answered by this study applying embedded monomer- and dimer-fragmentation methods to the harmonic ZPVE of hydrogen fluoride clusters, hydrogen fluoride crystal, and water clusters. Our findings are as follows: (1) ZPVE are reproduced accurately by both fragmentation schemes within a few percents of exact values or a few tenths of 1 kcal mol(-1) per molecule even for crystalline hydrogen fluoride, which has acoustic phonons. (2) Both the monomer- and dimer-based fragmentation are nearly equally accurate and useful for the absolute values of ZPVE, but the latter is more reliable than the former in reproducing the relative ZPVE of cluster isomers of the same size. (3) The embedding field is essential as it renders nonzero frequencies to the translational and rotational motions of monomers and dimers, accounting for the pseudo-translational and librational motions of the entire clusters or crystals. (4) Some of these low-frequency modes of fragments are calculated to have imaginary frequencies because the fragments are not at their equilibrium geometries, causing ZPVE to be complex. The imaginary part of ZPVE, which is nonphysical and is guaranteed to vanish in the exact limit of the many-body expansion, is nonetheless a useful estimate of errors in the real part. PMID:23145714

Sode, Olaseni; Hirata, So

2012-11-01

309

Design and characterization of an electromagnetic energy harvester for vehicle suspensions  

NASA Astrophysics Data System (ADS)

During the everyday usage of an automobile, only 10-16% of the fuel energy is used to drive the car—to overcome the resistance from road friction and air drag. One important loss is the dissipation of vibration energy by shock absorbers in the vehicle suspension under the excitation of road irregularity and vehicle acceleration or deceleration. In this paper we design, characterize and test a retrofit regenerative shock absorber which can efficiently recover the vibration energy in a compact space. Rare-earth permanent magnets and high permeable magnetic loops are used to configure a four-phase linear generator with increased efficiency and reduced weight. The finite element method is used to analyze the magnetic field and guide the design optimization. A theoretical model is created to analytically characterize the waveforms and regenerated power of the harvester at various vibration amplitudes, frequencies, equilibrium positions and design parameters. It was found that the waveform and RMS voltage of the individual coils will depend on the equilibrium position but the total energy will not. Experimental studies of a 1:2 scale prototype are conducted and the results agree very well with the theoretical predictions. Such a regenerative shock absorber will be able to harvest 16-64 W power at 0.25-0.5 m s - 1 RMS suspension velocity.

Zuo, Lei; Scully, Brian; Shestani, Jurgen; Zhou, Yu

2010-04-01

310

Modeling and nonlinear analysis of piezoelectric energy harvesting from transverse galloping  

NASA Astrophysics Data System (ADS)

A model for harvesting energy from galloping oscillations of a bar with an equilateral triangle cross-section attached to two cantilever beams is presented. The energy is harvested by attaching piezoelectric sheets to cantilever beams holding the bar. The derived nonlinear distributed-parameter model is validated with previous experimental results. The quasi-steady approximation is used to model the aerodynamic loads. The power levels that can be generated from these vibrations, and the variations of these levels with the load resistance and wind speed, are determined. Linear analysis is performed to validate the onset of galloping speed with experimental measurements. The effects of the electrical load resistance on the onset of galloping are then investigated. The results show that the electrical load resistance affects the onset speed of galloping. A nonlinear analysis is also performed to determine the effects of the electrical load resistance and the nonlinear torsional spring on the level of the harvested power. The results show that maximum levels of harvested power are accompanied by minimum transverse displacement amplitudes. It is also demonstrated that there is an optimum load resistance that maximizes the level of the harvested power.

Abdelkefi, Abdessattar; Yan, Zhimiao; Hajj, Muhammad R.

2013-02-01

311

Aeroelastic flutter energy harvester design: the sensitivity of the driving instability to system parameters  

NASA Astrophysics Data System (ADS)

This study examines the design parameters affecting the stability characteristics of a novel fluid flow energy harvesting device powered by aeroelastic flutter vibrations. The energy harvester makes use of a modal convergence flutter instability to generate limit cycle bending oscillations of a cantilevered piezoelectric beam with a small flap connected to its free end by a revolute joint. The critical flow speed at which destabilizing aerodynamic effects cause self-excited vibrations of the structure to emerge is essential to the design of the energy harvester because it sets the lower bound on the operating wind speed and frequency range of the system. A linearized analytic model of the device that accounts for the three-way coupling between the structural, unsteady aerodynamic, and electrical aspects of the system is used to examine tuning several design parameters while the size of the system is held fixed. The effects on the aeroelastic system dynamics and relative sensitivity of the flutter stability boundary are presented and discussed. A wind tunnel experiment is performed to validate the model predictions for the most significant system parameters.

Bryant, Matthew; Wolff, Eric; Garcia, Ephrahim

2011-12-01

312

Experimental validation of a distributed parameter piezoelectric bimorph cantilever energy harvester  

NASA Astrophysics Data System (ADS)

Recent rapid advances in low-power portable electronic applications have motivated researchers and industry to explore schemes to embed an endless power supply mechanism within these systems. These self-charging embedded power supply systems convert ambient energy (vibration, solar, wind, etc) into electrical energy and subsequently provide power to these portable applications. Ambient vibration is one of the most promising sources of energy as it is abundantly present in indoor/outdoor systems. This paper discusses briefly the mathematical model of a bimorph piezoelectric cantilever beam with distributed inertia, and its experimental validation. Research on such a component typically included a tip mass, which reduced the influence of the distributed inertia of the beam and restricted effective operation to low frequencies. The present work excludes the tip mass and only the distributed mass of the harvester is considered. Due to the coupled electromechanical nature of piezoelectric materials, the effects of electrical coupling on the mechanical properties of the harvester are investigated, particularly the dependence of the induced additional stiffness and damping on the electrical load. Both the model and the experimental results show that the resonance frequency and the response amplitude of the harvester exhibit considerable shifts due to the electrical coupling. The experimental work uses both magnitude and Nyquist plots of the electromechanical frequency response functions to thoroughly validate the accuracy and applicability of the distributed parameter model at higher frequencies than previously considered.

Rafique, S.; Bonello, P.

2010-09-01

313

An active piezoelectric energy extraction method for pressure energy harvesting  

NASA Astrophysics Data System (ADS)

This paper presents an energy harvesting technique to power autonomous systems and more particularly active implantable medical devices. We employ a piezoelectric diaphragm placed in a fluidic environment such as blood subjected to very low frequency (2 Hz) pressure variations that is deflected in a quasi-static manner and transduces mechanical energy into electrical energy. In order to maximize energy generation and to get the most out of a given piezoelectric device, we propose to apply an optimized method to extract the piezoelectrically generated charge through the application of a controlled voltage. We believe that this method could be one of the improvement levers to achieve self-powered miniaturized implants. An analytical model is presented and shows that within its validity domain, the extracted energy is proportional to the desired applied voltage. Taking power electronics losses into account can yield a theoretical increase in the extracted energy of several thousand per cent. Experimental measurements in a pressure chamber have been carried out whose results corroborate the proposed model. For the tested setup, the application of a 10 V peak amplitude square-wave voltage increased the extracted energy by a factor of nine compared to a classical rectifier-based energy harvesting method.

Deterre, M.; Lefeuvre, E.; Dufour-Gergam, E.

2012-08-01

314

On the performance and resonant frequency of electromagnetic induction energy harvesters  

NASA Astrophysics Data System (ADS)

This paper investigates the linear response of an archetypal energy harvester that uses electromagnetic induction to convert ambient vibration into electrical energy. In contrast with most prior works, the influence of the circuit inductance is not assumed negligible. Instead, we highlight parameter regimes where the inductance can alter resonance and derive an expression for the resonant frequency. The governing equations consider the case of a vibratory generator directly powering a resistive load. These equations are non-dimensionalized and analytical solutions are obtained for the system's response to single harmonic, periodic, and stochastic environmental excitations. The presented analytical solutions are then used to study the power delivered to an electrical load.

Mann, B. P.; Sims, N. D.

2010-04-01

315

A Circuit Prototype for Dielectric Polymer Energy Harvesting System  

Microsoft Academic Search

Recent development of Dielectric Electro Active Polymer (DEAP) for energy harvesting has gained a lot of attention for research. At the current time most investigations focus on the mechanical-to-electric energy conversion. In this paper we discussed the overall energy conversion circuit. Theoretical analysis shows the energy conversion efficiency largely depends on the circuit topology. While the previously suggested circuit may

Feng Ge; Wei Wang; Naval H. Gupte; Ken Choi; Gyungsoo Kang; SooHyun Kim

2011-01-01

316

Stability Analysis and Power Optimization for Energy Harvesting Cooperative Networks  

Microsoft Academic Search

In this letter, we investigate the effects of network- layer cooperation in a wireless three-node network with energy- harvesting nodes and bursty data traffic. By modelling energy har- vesting in each node as a queue (buffer) that stores the received energy, we study the interaction between data and energy queues when only knowledge of the arrival rates is available. The

Ioannis Krikidis; Themistoklis Charalambous; John S. Thompson

2012-01-01

317

Development of MEMS based pyroelectric thermal energy harvesters  

NASA Astrophysics Data System (ADS)

The efficient conversion of waste thermal energy into electrical energy is of considerable interest due to the huge sources of low-grade thermal energy available in technologically advanced societies. Our group at the Oak Ridge National Laboratory (ORNL) is developing a new type of high efficiency thermal waste heat energy converter that can be used to actively cool electronic devices, concentrated photovoltaic solar cells, computers and large waste heat producing systems, while generating electricity that can be used to power remote monitoring sensor systems, or recycled to provide electrical power. The energy harvester is a temperature cycled pyroelectric thermal-to-electrical energy harvester that can be used to generate electrical energy from thermal waste streams with temperature gradients of only a few degrees. The approach uses a resonantly driven pyroelectric capacitive bimorph cantilever structure that potentially has energy conversion efficiencies several times those of any previously demonstrated pyroelectric or thermoelectric thermal energy harvesters. The goals of this effort are to demonstrate the feasibility of fabricating high conversion efficiency MEMS based pyroelectric energy converters that can be fabricated into scalable arrays using well known microscale fabrication techniques and materials. These fabrication efforts are supported by detailed modeling studies of the pyroelectric energy converter structures to demonstrate the energy conversion efficiencies and electrical energy generation capabilities of these energy converters. This paper reports on the modeling, fabrication and testing of test structures and single element devices that demonstrate the potential of this technology for the development of high efficiency thermal-to-electrical energy harvesters.

Hunter, Scott R.; Lavrik, Nickolay V.; Bannuru, Thirumalesh; Mostafa, Salwa; Rajic, Slo; Datskos, Panos G.

2011-05-01

318

Development of MEMS based pyroelectric thermal energy harvesters  

SciTech Connect

The efficient conversion of waste thermal energy into electrical energy is of considerable interest due to the huge sources of low-grade thermal energy available in technologically advanced societies. Our group at the Oak Ridge National Laboratory (ORNL) is developing a new type of high efficiency thermal waste heat energy converter that can be used to actively cool electronic devices, concentrated photovoltaic solar cells, computers and large waste heat producing systems, while generating electricity that can be used to power remote monitoring sensor systems, or recycled to provide electrical power. The energy harvester is a temperature cycled pyroelectric thermal-to-electrical energy harvester that can be used to generate electrical energy from thermal waste streams with temperature gradients of only a few degrees. The approach uses a resonantly driven pyroelectric capacitive bimorph cantilever structure that potentially has energy conversion efficiencies several times those of any previously demonstrated pyroelectric or thermoelectric thermal energy harvesters. The goals of this effort are to demonstrate the feasibility of fabricating high conversion efficiency MEMS based pyroelectric energy converters that can be fabricated into scalable arrays using well known microscale fabrication techniques and materials. These fabrication efforts are supported by detailed modeling studies of the pyroelectric energy converter structures to demonstrate the energy conversion efficiencies and electrical energy generation capabilities of these energy converters. This paper reports on the modeling, fabrication and testing of test structures and single element devices that demonstrate the potential of this technology for the development of high efficiency thermal-to-electrical energy harvesters.

Hunter, Scott Robert [ORNL; Lavrik, Nickolay V [ORNL; Bannuru, Thirumalesh [ORNL; Mostafa, Salwa [ORNL; Rajic, Slobodan [ORNL; Datskos, Panos G [ORNL

2011-01-01

319

Underwater energy harvesting from a heavy flag hosting ionic polymer metal composites  

NASA Astrophysics Data System (ADS)

In this paper, we analyze underwater energy harvesting from the flutter instability of a heavy flag hosting an ionic polymer metal composite (IPMC). The heavy flag comprises a highly compliant membrane with periodic metal reinforcements to maximize the weight and minimize the bending stiffness, thus promoting flutter at moderately low flow speed. The IPMC is mechanically attached to the host flag and connected to an external load. The entire structure is immersed in a mean flow whose intensity is parametrically varied to explore the onset of flutter instability along with the relation between the vibration frequency and the mean flow speed. Manageable theoretical models for fluid-structure interaction and IPMC response are presented to inform the harvester design and interpret experimental data. Further, optimal parameters for energy scavenging maximization, including resistive load and flow conditions, are identified.

Giacomello, Alberto; Porfiri, Maurizio

2011-04-01

320

Energy harvesting from flutter instabilities of heavy flags in water through ionic polymer metal composites  

NASA Astrophysics Data System (ADS)

In this paper, we analyze underwater energy harvesting from the flutter instability of a heavy flag hosting an ionic polymer metal composite (IPMC). The heavy flag comprises a highly compliant membrane with periodic metal reinforcements to maximize the weight and minimize the bending stiffness, thus promoting flutter at moderately low flow speed. An IPMC strip is mechanically attached to the host flag and connected to an external load. The entire structure is immersed in a background flow whose intensity is parametrically varied to explore the onset of flutter instability along with the relation between the vibration frequency and the mean flow speed. Manageable theoretical models for fluid-structure interaction and IPMC response are presented to inform the harvester design and interpret experimental data. Further, optimal parameters for energy scavenging maximization, including resistive load and flow conditions, are identified.

Giacomello, Alberto; Porfiri, Maurizio

2011-03-01

321

Comparative analysis of piezoelectric power harvesting circuits for rechargeable batteries  

Microsoft Academic Search

Using piezoelectric materials to harvest energy from ambient vibrations to power wireless sensors has been of great interest over the past few years. Due to the power output of the piezoelectric materials is relatively low, rechargeable battery is considered as one kind of energy storage to accumulate the harvested energy for intermittent use. Piezoelectric harvesting circuits for rechargeable batteries have

Mingjie Guan; Wei-Hsin Liao

2005-01-01

322

Optimizing efficiency of energy harvesting by macro-fiber composites  

NASA Astrophysics Data System (ADS)

The decreasing energy consumption of today's portable electronics has invoked the possibility of energy harvesting from ambient environment for self power supply. One common and simple method for energy harvesting is to utilize the direct piezoelectric effect. Compared to traditional piezoelectric materials such as lead zirconate titanate (PZT), macro-fiber composites (MFC) are featured in their flexibility of large deformation. However, the energy generated by MFC is still far smaller than that required by electronics at present. In this paper, an energy harvesting system prototype with MFC patches bonded to a cantilever beam is fabricated and tested. A finite element analysis (FEA) model is established to estimate the output voltage of MFC harvester. The energy accumulation procedure in the capacitor is simulated by using the electronic design automation (EDA) software. The simulation results are validated by the experimental ones. Subsequently, the electrical properties of MFC as well as the geometry configurations of the cantilever beam and MFC are parametrically studied by combining the FEA and EDA simulations for optimal energy harvesting efficiency.

Tang, Lihua; Yang, Yaowen; Li, Hongyun

2008-12-01

323

Harvesting energy from the counterbalancing (weaving) movement in bicycle riding.  

PubMed

Bicycles are known to be rich source of kinetic energy, some of which is available for harvesting during speedy and balanced maneuvers by the user. A conventional dynamo attached to the rim can generate a large amount of output power at an expense of extra energy input from the user. However, when applying energy conversion technology to human powered equipments, it is important to minimize the increase in extra muscular activity and to maximize the efficiency of human movements. This study proposes a novel energy harvesting methodology that utilizes lateral oscillation of bicycle frame (weaving) caused by user weight shifting movements in order to increase the pedaling force in uphill riding or during quick speed-up. Based on the 3D motion analysis, we designed and implemented the prototype of an electro-dynamic energy harvester that can be mounted on the bicycle's handlebar to collect energy from the side-to-side movement. The harvester was found to generate substantial electric output power of 6.6 mW from normal road riding. It was able to generate power even during uphill riding which has never been shown with other approaches. Moreover, harvesting of energy from weaving motion seems to increase the economy of cycling by helping efficient usage of human power. PMID:23112598

Yang, Yoonseok; Yeo, Jeongjin; Priya, Shashank

2012-07-30

324

Indoor solar energy harvesting for sensor network router nodes  

Microsoft Academic Search

A unique method has been developed to scavenge solar energy from monocrystalline solar cells to power wireless router nodes that are used in indoor applications. This method eliminates the need to use alkaline batteries that require frequent replacement from time to time. The system consists of two key components viz. an energy harvesting unit and an energy storage module. The

Abhiman Hande; Todd Polk; William Walker; Dinesh Bhatia

2007-01-01

325

Evaluation of motions and actuation methods for biomechanical energy harvesting  

Microsoft Academic Search

This paper addresses energy harvesting from biomechanical motions. Such a technique is useful for powering small portable devices, such as wireless phones, music players, and digital assistants. For very low power devices, biomechanical energy may be enough to provide baseload power. In others, such as cell phones (which typically requires up to 3 W), biomechanical energy would recharge batteries for

Penglin Niu; Patrick Chapman; Raziel Riemer; Xudong Zhang

2004-01-01

326

Stationary response of nonlinear magneto-piezoelectric energy harvester systems under stochastic excitation  

NASA Astrophysics Data System (ADS)

Recent years have shown increasing interest of researchers in energy harvesting systems designed to generate electrical energy from ambient energy sources, such as mechanical excitations. In a lot of cases excitation patterns of such systems exhibit random rather than deterministic behaviour with broad-band frequency spectra. In this paper, we study the efficiency of vibration energy harvesting systems with stochastic ambient excitations by solving corresponding Fokker-Planck equations. In the system under consideration, mechanical energy is transformed by a piezoelectric transducer in the presence of mechanical potential functions which are governed by magnetic fields applied to the device. Depending on the magnet positions and orientations the vibrating piezo beam system is subject to characteristic potential functions, including single and double well shapes. Considering random excitation, the probability density function (pdf) of the state variables can be calculated by solving the corresponding Fokker-Planck equation. For this purpose, the pdf is expanded into orthogonal polynomials specially adapted to the problem and the residual is minimized by a Galerkin procedure. The power output has been estimated as a function of basic potential function parameters determining the characteristic pdf shape.

Martens, W.; von Wagner, U.; Litak, G.

2013-09-01

327

Energy Harvesting for Structural Health Monitoring Sensor Networks  

SciTech Connect

This report has been developed based on information exchanges at a 2.5-day workshop on energy harvesting for embedded structural health monitoring (SHM) sensing systems that was held June 28-30, 2005, at Los Alamos National Laboratory. The workshop was hosted by the LANL/UCSD Engineering Institute (EI). This Institute is an education- and research-focused collaboration between Los Alamos National Laboratory (LANL) and the University of California, San Diego (UCSD), Jacobs School of Engineering. A Statistical Pattern Recognition paradigm for SHM is first presented and the concept of energy harvesting for embedded sensing systems is addressed with respect to the data acquisition portion of this paradigm. Next, various existing and emerging sensing modalities used for SHM and their respective power requirements are summarized, followed by a discussion of SHM sensor network paradigms, power requirements for these networks and power optimization strategies. Various approaches to energy harvesting and energy storage are discussed and limitations associated with the current technology are addressed. This discussion also addresses current energy harvesting applications and system integration issues. The report concludes by defining some future research directions and possible technology demonstrations that are aimed at transitioning the concept of energy harvesting for embedded SHM sensing systems from laboratory research to field-deployed engineering prototypes.

G. Park, C. R. Farrar, M. D. Todd, W. Hodgkiss, T. Rosing

2007-02-26

328

Energy harvesting: an integrated view of materials, devices and applications.  

PubMed

Energy harvesting refers to the set of processes by which useful energy is captured from waste, environmental, or mechanical sources and is converted into a usable form. The discipline of energy harvesting is a broad topic that includes established methods and materials such as photovoltaics and thermoelectrics, as well as more recent technologies that convert mechanical energy, magnetic energy and waste heat to electricity. This article will review various state-of-the-art materials and devices for direct energy conversion and in particular will include multistep energy conversion approaches. The article will highlight the nano-materials science underlying energy harvesting principles and devices, but also include more traditional bulk processes and devices as appropriate and synergistic. Emphasis is placed on device-design innovations that lead to higher efficiency energy harvesting or conversion technologies ranging from the cm/mm-scale down to MEMS/NEMS (micro- and nano-electromechanical systems) devices. Theoretical studies are reviewed, which address transport properties, crystal chemistry, thermodynamic analysis, energy transfer, system efficiency and device operation. New developments in experimental methods; device design and fabrication; nanostructured materials fabrication; materials properties; and device performance measurement techniques are discussed. PMID:23186865

Radousky, H B; Liang, H

2012-11-27

329

Energy harvesting: an integrated view of materials, devices and applications  

NASA Astrophysics Data System (ADS)

Energy harvesting refers to the set of processes by which useful energy is captured from waste, environmental, or mechanical sources and is converted into a usable form. The discipline of energy harvesting is a broad topic that includes established methods and materials such as photovoltaics and thermoelectrics, as well as more recent technologies that convert mechanical energy, magnetic energy and waste heat to electricity. This article will review various state-of-the-art materials and devices for direct energy conversion and in particular will include multistep energy conversion approaches. The article will highlight the nano-materials science underlying energy harvesting principles and devices, but also include more traditional bulk processes and devices as appropriate and synergistic. Emphasis is placed on device-design innovations that lead to higher efficiency energy harvesting or conversion technologies ranging from the cm/mm-scale down to MEMS/NEMS (micro- and nano-electromechanical systems) devices. Theoretical studies are reviewed, which address transport properties, crystal chemistry, thermodynamic analysis, energy transfer, system efficiency and device operation. New developments in experimental methods; device design and fabrication; nanostructured materials fabrication; materials properties; and device performance measurement techniques are discussed.

Radousky, H. B.; Liang, H.

2012-12-01

330

Long term performance of wearable transducer for motion energy harvesting  

NASA Astrophysics Data System (ADS)

Personal electronic devices such as cell phones, GPS and MP3 players have traditionally depended on battery energy storage technologies for operation. By harvesting energy from a person's motion, these devices may achieve greater run times without increasing the mass or volume of the electronic device. Through the use of a flexible piezoelectric transducer such as poly-vinylidene fluoride (PVDF), and integrating it into a person's clothing, it becomes a 'wearable transducer'. As the PVDF transducer is strained during the person's routine activities, it produces an electrical charge which can then be harvested to power personal electronic devices. Existing wearable transducers have shown great promise for personal motion energy harvesting applications. However, they are presently physically bulky and not ergonomic for the wearer. In addition, there is limited information on the energy harvesting performance for wearable transducers, especially under realistic conditions and for extended cyclic force operations - as would be experienced when worn. In this paper, we present experimental results for a wearable PVDF transducer using a person's measured walking force profile, which is then cycled for a prolonged period of time using an experimental apparatus. Experimental results indicate that after an initial drop in performance, the transducer energy harvesting performance does not substantially deteriorate over time, as less than 10% degradation was observed. Longevity testing is still continuing at CSIRO.

McGarry, Scott A.; Behrens, Sam

2010-03-01

331

Studying piezoelectric nanowires and nanowalls for energy harvesting  

Microsoft Academic Search

Piezoelectric nanostructures can transduce mechanical energy into electrical energy for powering implantable microsystems for in-vivo biomedical applications (smart systems for drug delivery, ?TAS, microsensors for diagnostic and therapeutic applications …) and sensors networks for high-density, low cost environment control. Zinc oxide nanowires and microwires have been recently used to convert vibrations into electrical energy. Here, we explain some previously reported

Christian Falconi; Giulia Mantini; Arnaldo D’Amico; Zhong Lin Wang

2009-01-01

332

An Efficient Solar Energy Harvester for Wireless Sensor Nodes  

Microsoft Academic Search

Solar harvesting circuits have been recently proposed to in- crease the autonomy of embedded systems. One key design chal- lenge is how to optimize the efficiency of solar energy collection under non stationary light conditions. This paper proposes a sca- venger that exploits miniaturized photovoltaic modules to perform automatic maximum power point tracking at a minimum energy cost. The system

Davide Brunelli; Luca Benini; Clemens Moser; Lothar Thiele

2008-01-01

333

Real-time scheduling for energy harvesting sensor nodes  

Microsoft Academic Search

Energy harvesting has recently emerged as a feasible option to increase the oper- ating time of sensor networks. If each node of the network, however, is powered by a fluctuating energy source, common power management solutions have to be reconceived. This holds in particular if real-time responsiveness of a given application has to be guaranteed. Task scheduling at the single

Clemens Moser; Davide Brunelli; Lothar Thiele; Luca Benini

2007-01-01

334

Analysis of power output for piezoelectric energy harvesting systems  

Microsoft Academic Search

Power harvesting refers to the practice of acquiring energy from the environment which would be otherwise wasted and converting it into usable electric energy. Much work has been done on studying the optimal AC power output, while little has considered the AC–DC output. This article investigates the optimal AC–DC power generation for a rectified piezoelectric device. In contrast with estimates

Y C Shu; I C Lien

2006-01-01

335

Battery-less piezoceramics mode energy harvesting for automobile TPMS  

Microsoft Academic Search

A battery-less tire pressure monitoring system (TPMS) with piezoceramics mode energy harvesting is presented. A chip of power recovery circuit at piezoceramics mode is designed and implemented at Chartered 0.35 ¿m high voltage CMOS process. Based on testing results, with the piezoceramics, the chip converts mechanical strain energy to DC power which provides stable voltage output around 3 V, and

Liji Wu; Yixiang Wang; Chen Jia; Chun Zhang

2009-01-01

336

Low-frequency magnetic energy harvest using multiferroic composite plates  

NASA Astrophysics Data System (ADS)

It is shown with a theoretical bending model that a laminated plate with piezoelectric and piezomagnetic layers can be used to harvest magnetic energy at relatively low frequencies. The output electric power and the energy conversion efficiency are calculated. The load dependence of the magnetoelectric coupling coefficient is obtained.

Zhang, C. L.; Yang, J. S.; Chen, W. Q.

2010-05-01

337

Wireless sensor networks with energy harvesting technologies: a game-theoretic approach to optimal energy management  

Microsoft Academic Search

Energy harvesting technologies are required for autonomous sensor networks for which using a power source from a fixed utility or manual battery recharging is infeasible. An energy harvesting device (e.g., a solar cell) converts different forms of environmental energy into electricity to be supplied to a sensor node. However, since it can produce energy only at a limited rate, energy

Dusit Niyato; Ekram Hossain; Mohammad Rashid; Vijay Bhargava

2007-01-01

338

Vibration-to-electric energy conversion  

Microsoft Academic Search

A system is proposed to convert ambient mechanical vibration into electrical energy for use in powering autonomous low-power electronic systems. The energy is transduced through the use of a variable capacitor, which has been designed with MEMS (microelectromechanical systems) tech- nology. A low-power controller IC has been fabricated in a 0 6µm CMOS pro- cess and has been tested and

Scott Meninger; Jose Oscar Mur-Miranda; Rajeevan Amirtharajah; Anantha Chandrakasan; Jeffrey Lang

1999-01-01

339

Energy harvesting using a PZT ceramic multilayer stack  

NASA Astrophysics Data System (ADS)

In this paper, the interdisciplinary energy harvesting issues on piezoelectric energy harvesting were investigated using a ‘33’ mode (mechanical stress and/or electric field are in parallel to the polarization direction) lead zirconate titanate multilayer piezoelectric stack (PZT-Stack). Key energy harvesting characteristics including the generated electrical energy/power in the PZT-Stack, the mechanical to electrical energy conversion efficiency, the power delivered from the PZT-Stack to a resistive load, the electrical charge/energy transferred from the PZT-Stack to a super-capacitor were systematically addressed. Theoretical models for power generation and delivery to a resistive load were proposed and experimentally affirmed. In a quasi-static regime, 70% generated electrical powers were delivered to matched resistive loads. A 35% mechanical to electrical energy conversion efficiency, which is more than 4 times higher than other reports, for the PZT-Stack had been obtained. The generated electrical power and power density were significantly higher than those from a similar weight and size cantilever-type piezoelectric harvester in both resonance and off-resonance modes. In addition, our study indicated that the capacitance and piezoelectric coefficient of the PZT-Stack were strongly dependent on the dynamic stress.

Xu, Tian-Bing; Siochi, Emilie J.; Kang, Jin Ho; Zuo, Lei; Zhou, Wanlu; Tang, Xiudong; Jiang, Xiaoning

2013-06-01

340

Practical implementation of piezoelectric energy harvesting synchronized switching schemes  

NASA Astrophysics Data System (ADS)

Many closed-loop control methods for increasing the power output from piezoelectric energy harvesters have been investigated over the past decade. Initial work started with the application of Maximum Power Point Tracking techniques (MPPT) developed for solar power. More recent schemes have focused on taking advantage of the capacitive nature of piezoelectric harvesters to manipulate the transfer of energy from the piezoelectric to the storage element. There have been a couple of main techniques investigated in the literature: Synchronous Charge Extraction (SCE), Synchronized Switching and Discharging to a Capacitor through an Inductor (SSDCI), Synchronized Switch Harvesting on an Inductor (SSHI), and Piezoelectric Pre-Biasing (PPB). While significant increases in harvested power are seen both theoretically and experimentally using powerful external control systems, the applicability of these methods depends highly on the performance and efficiency of the system which implements the synchronized switching. Many piezoelectric energy harvesting systems are used to power devices controlled by a microcontroller (MCU), making them readily available for switching control methods. This work focuses on the practical questions which dictate the applicability of synchronized switching techniques using MCU-based switching control.

Schlichting, Alexander D.; Phadke, Ajay; Garcia, Ephrahim

2013-04-01

341

Vibrational energy transport in the presence of intrasite vibrational energy redistribution  

NASA Astrophysics Data System (ADS)

The mechanism of vibrational energy flow is studied in a regime where a diffusion equation is likely to break down, i.e., on length scales of a few chemical bonds and time scales of a few picoseconds. This situation occurs, for example, during photochemical reactions in protein environment. To that end, a toy model is introduced that on the one hand mimics the vibrational normal mode distribution of proteins, and on the other hand is small enough to numerically time propagate the system fully quantum mechanically. Comparing classical and quantum-mechanical results, the question is addressed to what extent the classical nature of the molecular dynamics simulations (which would be the only choice for the modeling of a real molecular system) affects the vibrational energy flow mechanism. Small differences are found which are due to the different ways classical and quantum mechanics distribute thermal energy over vibrational modes. In either case, a ballistic and a diffusive phase can be identified. For these small length and time scales, the latter is governed by intrasite vibrational energy redistribution, since vibrational energy does not necessarily thermalize completely within individual peptide units. Overall, the model suggests a picture that unifies many of the observations made recently in experiments.

Schade, Marco; Hamm, Peter

2009-07-01

342

Wireless energy transmission to supplement energy harvesters in sensor network applications  

SciTech Connect

In this paper we present a method for coupling wireless energy transmission with traditional energy harvesting techniques in order to power sensor nodes for structural health monitoring applications. The goal of this study is to develop a system that can be permanently embedded within civil structures without the need for on-board power sources. Wireless energy transmission is included to supplement energy harvesting techniques that rely on ambient or environmental, energy sources. This approach combines several transducer types that harvest ambient energy with wireless transmission sources, providing a robust solution that does not rely on a single energy source. Experimental results from laboratory and field experiments are presented to address duty cycle limitations of conventional energy harvesting techniques, and the advantages gained by incorporating a wireless energy transmission subsystem. Methods of increasing the efficiency, energy storage medium, target applications and the integrated use of energy harvesting sources with wireless energy transmission will be discussed.

Farinholt, Kevin M [Los Alamos National Laboratory; Taylor, Stuart G [Los Alamos National Laboratory; Park, Gyuhae [Los Alamos National Laboratory; Farrar, Charles R [Los Alamos National Laboratory

2010-01-01

343

A self-adaptive switched-capacitor voltage converter with dynamic input load control for energy harvesting  

Microsoft Academic Search

This paper presents an implementation of a fully-integrated switched capacitor voltage converter with self-adjusting source loading. A charge control unit ensures improved load matching to the power source, which can be an RFID antenna or vibration energy harvesting generator. In conjunction with an adaptive stacking scheme voltage-up conversion is also realized leading to capacitor storage voltages which are higher than

Dominic Maurath; Yiannos Manoli

2009-01-01

344

Vibrational energy dynamics of normal and deuterated liquid benzene.  

PubMed

Ultrafast Raman spectroscopy with infrared (IR) excitation is used to study vibrational energy dynamics of ambient temperature liquids benzene and benzene-d(6). After IR pumping of a CH-stretch or CD-stretch parent excitation, the redistribution of vibrational energy is probed with anti-Stokes Raman. Ten benzene or 12 benzene-d(6) vibrations out of 30 total have large enough cross sections to be observed. The pathways, quantum yields, and lifetimes for energy transfer among these vibrations are quantified. Using a CCl(4) molecular thermometer, we demonstrate an ultrafast Raman calorimetry method which allows measurement of the rate that benzene vibrational energy is dissipated into the bath. On the basis of energy conservation, we then determine the time-dependent dissipation of aggregate vibrational energy from the unobserved, "invisible" vibrations. During the approximately 1 ps IR excitation process, vibrational energy is coherently redistributed to several vibrational modes ("coherently" means the rate is faster than (T(2))(-1) of the pumped transition). This energy is then further redistributed in an incoherent intramolecular vibrational relaxation process with a 6 ps T(1) time constant. The subsequent dynamics involve energy transfer processes accompanied by vibrational energy dissipation to the bath. This vibrational cooling process has a half-life of 30 ps in benzene and 20 ps in benzene-d(6), and thermalization is complete in approximately 100 ps. The observed strongly Raman-active vibrations have about the same amount of energy per mode as the invisible vibrations. The invisible vibrational energy in benzene decays somewhat faster than the observed energy. These two decay rates are about the same in benzene-d(6). PMID:19186952

Seong, Nak-Hyun; Fang, Ying; Dlott, Dana D

2009-02-02

345

Estimation of Electric Charge Output for Piezoelectric Energy Harvesting  

Microsoft Academic Search

Piezoelectric materials (PZT) can be used as mechanisms to transfer mechanical energy, usually ambient vibration, into electrical energy that can be stored and used to power other devices. With the recent advances in wireless and micro-electro-mechanical-systems (MEMS) technology, sensors can be placed in exotic and remote locations. As these devices are wireless it becomes necessary that they have their own

H. A. Sodano; D. J. Inman

2004-01-01

346

Comparison of Piezoelectric Energy Harvesting Devices for Recharging Batteries  

Microsoft Academic Search

Piezoelectric materials can be used as a means of transforming ambient vibrations into electrical energy that can then be stored and used to power other devices. With the recent surge of microscale devices, piezoelectric power generation can provide a convenient alternative to traditional power sources used to operate certain types of sensors\\/actuators, telemetry, and MEMS devices. However, the energy produced

Henry A. Sodano; Daniel J. Inman

2005-01-01

347

Analyses of power output of piezoelectric energy-harvesting devices directly connected to a load resistor using a coupled piezoelectric-circuit finite element method  

Microsoft Academic Search

This paper presents, for the first time, a coupled piezoelectric-circuit finite element model (CPC-FEM) to analyze the power output of a vibration-based piezoelectric energy-harvesting device (EHD) when it is connected to a load resistor. Special focus is given to the effect of the load resistor value on the vibrational amplitude of the piezoelectric EHD, and thus on the current, voltage,

Meiling Zhu; Emma Worthington; James Njuguna

2009-01-01

348

High efficiency energy harvesting device with magnetic coupling for resonance frequency tuning  

NASA Astrophysics Data System (ADS)

Wireless sensors are becoming extremely popular for their ability to be employed in hostile and inaccessible locations to monitor various parameters of importance, and vibration energy harvesting shows great potential in powering these sensor networks. For efficient operation the device should operate in resonance at the environmental excitation frequency and hence requires a frequency tuning mechanism. Recently efforts have been attempted to broaden the frequency range of energy harvesting devices, but in terms of power density an efficient design methodology is lacking. In this work, a tunable energy harvesting device with high efficiency and power density is presented. The technique involves two single DOF's cantilever beams which are coupled in a novel fashion by means of magnetic force for resonance frequency tuning. Here the magnetic force acts as a variable stiffness coupling the two cantilever beams, allowing one to alter the corresponding resonance frequencies of the cantilever beams. Magnetic force of attraction and repulsion can be used to achieve the magnetic coupling and can increase the overall stiffness of either of the cantilever beams while decreasing the others. The total power output of the device is found to be between 180 ?W to 320 ?W.

Challa, Vinod R.; Prasad, M. G.; Fisher, Frank T.

2008-05-01

349

Nonlinear dynamics of galloping-based piezoaeroelastic energy harvesters  

NASA Astrophysics Data System (ADS)

The normal form is proposed as a tool to analyze the performance and reliability of galloping-based piezoaeroelastic energy harvesters. Two different harvesting systems are considered. The first system consists of a tip mass prismatic structure (isosceles 30° or square cross-section geometry) attached to a multilayered cantilever beam. The only source of nonlinearity in this system is the aerodynamic nonlinearity. The second system consists of an equilateral triangle cross-section bar attached to two cantilever beams. This system is designed to have structural and aerodynamic nonlinearities. The coupled governing equations for the structure's transverse displacement and the generated voltage are derived and analyzed for both systems. The effects of the electrical load resistance and the type of harvester on the onset speed of galloping are quantified. The results show that the onset speed of galloping is strongly affected by the load resistance for both types of harvesters. The normal form of the dynamic system near the onset of galloping (Hopf bifurcation) is then derived. Based on the nonlinear normal form, it is demonstrated that smaller levels of generated voltage or power are obtained for higher absolute values of the effective nonlinearity. For the first harvesting system, the results show a supercritical Hopf bifurcation for both isosceles 30° or square cross-section geometries. The nonlinear normal form shows that the isosceles triangle section (30°) is more efficient than the square section. For the second harvesting system, the normal form is used to identify the values of the nonlinear torsional spring which changes the harvester's instability. It is demonstrated that this critical value of the nonlinear torsional spring depends strongly on the load resistance.

Abdelkefi, A.; Yan, Z.; Hajj, M. R.

2013-09-01

350

Energy Harvesting for Structural Health Monitoring Sensor Networks.  

National Technical Information Service (NTIS)

This report has been developed based on information exchanges at a 2.5-day workshop on energy harvesting for embedded structural health monitoring (SHM) sensing systems that was held June 2830, 2005, at Los Alamos National Laboratory. The workshop was hos...

G. Park C. R. Farrar M. D. Todd W. Hodgkiss T. Rosing

2007-01-01

351

Piezoelectric Energy Harvesting with a Clamped Circular Plate: Experimental Study  

Microsoft Academic Search

In a companion article, a model for a clamped circular unimorph piezoelectric plate has been developed for the purpose of analyzing the influence of geometric design parameters and electrode configuration on the amount of electrical energy that can be harvested from an applied pressure source. It has been shown that the ratio of layer thickness (piezoelectric layer to substrate layer)

Sunghwan Kim; William W. Clark; Qing-Ming Wang

2005-01-01

352

Energy harvesting from the nonlinear oscillations of magnetic levitation  

Microsoft Academic Search

This paper investigates the design and analysis of a novel energy harvesting device that uses magnetic levitation to produce an oscillator with a tunable resonance. The governing equations for the mechanical and electrical domains are derived to show the designed system reduces to the form of a Duffing oscillator under both static and dynamic loads. Thus, nonlinear analyses are required

B. P. Mann; N. D. Sims

2009-01-01

353

Self-organized porphyrin nanomaterials for solar energy harvesting  

Microsoft Academic Search

New concepts in the design and function of organic dyes as sensitizers for solar energy harvesting are needed. Commercial viability constrains these designs: (a) cost effective synthesis, (b) long-term stability, and (c) an important goal is to reduce the environmental impact of the product at the end of its life cycle. Simple porphyrinoid dyes meet these constraints, but new modes

Ivana Radivojevic

2010-01-01

354

Design, fabrication, and testing of energy-harvesting thermoelectric generator  

Microsoft Academic Search

An energy-harvesting thermoelectric generator (TEG) is being developed to provide power for wireless sensors used in health monitoring of Navy machinery. TEGs are solid-state devices that convert heat directly into electricity without any moving parts. In this application, the TEGs utilize the heat transfer between shipboard waste heat sources and the ambient air to generate electricity. In order to satisfy

Velimir Jovanovic; Saeid Ghamaty

2006-01-01

355

Incoherent energy transfer within light-harvesting complexes  

NASA Astrophysics Data System (ADS)

Rate equations are used to model spectroscopic observation of incoherent energy transfer in light-harvesting antenna systems based upon known structures. A two-parameter two-dimensional model is proposed. The transfer rates obtained, by matching the fluorescent decay, are self-consistent within our model.

Ting, Julian Juhi-Lian

1999-10-01

356

Energy harvesting using AC machines with high effective pole count  

Microsoft Academic Search

In this paper, we investigate ways to improve the power conversion of small, rotating, permanent magnet AC machines at low rotor speeds in energy harvesting applications. One method is to increase the pole count, which increases the generator back-emf without also increasing the I2R losses, thereby increasing both torque density and conversion efficiency. One machine topology that has a high

Richard Geiger; Heath Hofmann

2008-01-01

357

Energy harvesting using AC machines with high effective pole count  

Microsoft Academic Search

In this thesis, ways to improve the power conversion of rotating generators at low rotor speeds in energy harvesting applications were investigated. One method is to increase the pole count, which increases the generator back-emf without also increasing the I2R losses, thereby increasing both torque density and conversion efficiency. One machine topology that has a high effective pole count is

Richard Theodore Geiger

2010-01-01

358

Economics of modifying harvesting systems to recover energy wood  

Microsoft Academic Search

Recent interest in the recovery of previously underutilized logging residues for energy has stimulated the development of a variety of technologies for bringing this resource to market. The most promising approach for the independent contractor working the south eastern United States is to incorporate residue recovery equipment into his existing harvesting system. Computer simulation was used to assess the potential

W. B. Stuart; C. D. Porter; T. A. Walbridge; R. G. Oderwald

1981-01-01

359

Designing photovoltaic cells for indoor energy harvesting systems  

Microsoft Academic Search

Recent research focuses on developing photovoltaic cells that are optimized for indoor conditions and therefore suitable for photovoltaic energy harvesting in micro systems. The available conditions for indoor photovoltaic cells are investigated and discussed concerning intensity and spectra. The influence of the parallel and series resistances on the efficiency of crystalline and amorphous Silicon devices with decreasing intensity are discussed

K. Ruhle; M. Freunek; L. M. Reindl; M. Kasemann

2012-01-01

360

A System Design Approach for Unattended Solar Energy Harvesting Supply  

Microsoft Academic Search

Remote devices, such as sensors and communications devices, require continuously available power. In many applications, conventional approaches are too expensive, too large, or unreliable. For short-term needs, primary batteries may be used. However, they do not scale up well for long-term installations. Instead, energy harvesting methods must be used. Here, a system design approach is introduced that results in a

Jonathan W. Kimball; Brian T. Kuhn; Robert S. Balog

2009-01-01

361

Engineered biomimicry for harvesting solar energy: a bird's eye view  

Microsoft Academic Search

All three methodologies of engineered biomimicry – bioinspiration, biomimetics, and bioreplication – are represented in current research on harvesting solar energy. Both processes and porous surfaces inspired by plants and certain marine animals, respectively, are being investigated for solar cells. Whereas dye-sensitized solar cells deploy artificial photosynthesis, bioinspired nanostructuring of materials in solar cells improves performance. Biomimetically textured coatings for

Raúl J. Martín-Palma; Akhlesh Lakhtakia

2012-01-01

362

Innovative microbial fuel cell for energy harvesting and corrosion protection  

Microsoft Academic Search

Microbial Fuel cells (MFCs) are batteries driven by bacteria. MFCs have the potential of powering small sensors in remote areas and disposing organic waste safely by harvesting the energy stored in the waste products. From previous research in this field, a few important factors for MFC performance have been identified. These include the internal resistance of MFC, the surface area

Chih-Chien Kung; Chung-Chiun Liu; Xiong Yu

2011-01-01

363

Vibrational energy levels of CH5+  

Microsoft Academic Search

We present a parallelized contracted basis-iterative method for calculating numerically exact vibrational energy levels of CH5+ (a 12-dimensional calculation). We use Radau polyspherical coordinates and basis functions that are products of eigenfunctions of bend and stretch Hamiltonians. The bend eigenfunctions are computed in a nondirect product basis with more than 200×106 functions and the stretch functions are computed in a

Xiao-Gang Wang; Tucker Carrington

2008-01-01

364

Validation of energy harvest modeling for X14 system  

NASA Astrophysics Data System (ADS)

Skyline Solar has developed a second generation medium concentration photovoltaic system with an optical concentration of around 14. The energy harvest model based on the first generation system has been updated and improved using field data. The model combines a bottom-up modeling approach based on performance of subcomponents such as mirrors and cells with a top-down approach based on measuring the system output under different environmental conditions. Improvement of the model includes the effect of non-uniformity of the light on the panel. The predicted energy ratio (ratio between the observed energy and expected energy) has been measured over a 10-month period and shows monthly variability below 2%, resulting in high confidence level for the mean of the expected energy harvest.

Finot, Marc; MacDonald, Bob; Lance, Tamir

2012-10-01

365

Performance enhancement of piezoelectric energy harvesters from wake galloping  

NASA Astrophysics Data System (ADS)

Experiments are performed to investigate the effects of wake galloping on the range of flow speeds over which a galloping-based piezoaeroelastic energy harvester can be effectively used. Two different upstream cylinders and a wide range of spacing between the upstream and downstream cylinders are considered. Bifurcation diagrams and type of instability for different setups are determined. The results show a complex relation between the upstream circular cylinder size, the spacing between the two cylinders, the flow speed, and the load resistance on one hand, and the level of harvested power on the other hand.

Abdelkefi, A.; Scanlon, J. M.; McDowell, E.; Hajj, M. R.

2013-07-01

366

Determination of Vibrational and Rotational Energy Levels of Water Vapor.  

National Technical Information Service (NTIS)

Water vapor absorbs energy in the infrared and invisible portions of the electromagnetic spectrum by two methods: Absorption of energy to increase its vibrational energy and/or absorption of energy to increase its rotational energy. Computer programs were...

D. L. Dobbins A. H. LaGrone

1967-01-01

367

Design and modeling of the trapezoidal electrodes array for electrets energy harvester  

NASA Astrophysics Data System (ADS)

Electrets-based electrostatic energy harvester for harvesting electrical energy from the ambient vibration is introduced and described in this paper. A new design of electrode structure called the trapezoidal electrodes and its electrets counterpart are designed, modeled and analyzed thoroughly to evaluate its performance. First, the theory is explained and the mathematical analysis is performed using Matlab/Simulink tool. Results of the analysis shows that the average output power harvested from the trapezoidal electrodes is ~1 mW from 20 Hz at 1 g inputs. Then, the 3D model of the electrodes and electrets structures are constructed, simulated and analyzed with Finite Element Modeling/Analysis (FEM/FEA) tool. Further, mechanical analysis carried out on the trapezoidal electrodes model indicates that it displaces laterally at 94 ?m and resonates at 113 Hz whereas the electrostatic analysis unveils 1895 pC of charge density induced on the trapezoidal electrodes from 450 VDC electrets potential. The optimized parameters derive from the analyses are used as a reference for fabrication of MEMS (Micro Electro-Mechanical System) physical device on a standard CMOS process technology.

Ahmad, M. R.; Md Khir, M. H.; Dennis, J. O.

2013-05-01

368

Lazy Scheduling for Energy Harvesting Sensor Nodes  

Microsoft Academic Search

The paper studies the case of a sensor node which is operating with the power generated by an environmental source. We present our model of an energy driven scheduling scenario that is characterized by the capacity of the node's energy storage, the deadlines and the power dissipation of the tasks to be performed. Since the execution of these tasks requires

Clemens Moser; Davide Brunelli; Lothar Thiele; Luca Benini

2006-01-01

369

Harvesting alternate energies from our planet  

NASA Astrophysics Data System (ADS)

Recent price fluctuations have focused attention on the phenomenal increase of global energy consumption in recent years. We have almost reached a peak in global oil production. Total world consumption of oil will rise by nearly 60% between 1999 and 2020. In 1999 consumption was 86 million barrels of oil per day, which has reached a peak of production extracted from most known oil reserves. These projections, if accurate, will present an unprecedented crisis to the global economy and industry. As an example, in the United States, nearly 40% of energy usage is provided by petroleum, of which nearly a third is used in transportation. An aggressive search for alternate energy sources, both renewable and nonrenewable, is vital. This article will review national and international perspectives on the exploration of alternate energies with a focus on energy derivable from the ocean.

Rath, Bhakta B.

2009-04-01

370

Consideration of Impedance Matching Techniques for Efficient Piezoelectric Energy Harvesting  

Microsoft Academic Search

This study investigates multiple levels of impedance-matching methods for piezoelectric energy harvesting in order to enhance the conversion of mechanical to electrical energy. First, the transduction rate was improved by using a high piezoelectric voltage constant (g) ceramic material having a magnitude of g33 = 40 times 10-3 V m\\/N. Second, a transducer structure, cymbal, was optimized and fabricated to

Hyeoungwoo Kim; Shashank Priya; Harry Stephanou; Kenji Uchino

2007-01-01

371

Green energy harvesting technology in 3D IC  

Microsoft Academic Search

Three dimensional integrated circuit (3D IC) is recognized as the breakthrough technology to be widely used in semiconductor industries in the next three years. The green energy harvesting technology is important for future 3D IC development. In this paper, the material and fabrication of the thermocouple structures are investigated for memory-on-logic 3D IC. The efficiency of such a green energy

Wei Wang; Weng Hong Teh

2010-01-01

372

An energy harvesting circuit for self-powered sensors  

Microsoft Academic Search

In this work we present a prototype circuit to harvest energy from radio waves or through magnetic coupling based on a stack of full-wave rectifiers with transistors working on sub-threshold region. This circuit will use as an input a field-to-voltage converter capable of outputting a 200mV waveform and is able to self-start without any other energy sources. The circuit presented

Jorge R. Fernandes; Miguel Martins; Moisés Piedade

2010-01-01

373

Perspectives on Energy-Harvesting Wireless Sensor Networks  

Microsoft Academic Search

\\u000a An energy-harvesting wireless sensor network (EHWSN) is an application-specific collection of wirelessly connected, highly\\u000a resource-constrained radios, which are independent and capable of sensing, storing, processing and forwarding data, and capable\\u000a of extracting energy from their environment. The network typically will have a connection to at least one less-constrained\\u000a “Gateway” or “Sink” radio that is connected to the internet either wirelessly

Mary Ann Ingram; Lakshmi Thanayankizil; Jin Woo Jung; Aravind Kailas

374

Bioinspired model of mechanical energy harvesting based on flexoelectric membranes.  

PubMed

Membrane flexoelectricity is an electromechanical coupling process that describes membrane electrical polarization due to bending and membrane bending under electric fields. In this paper we propose, formulate, and characterize a mechanical energy harvesting system consisting of a deformable soft flexoelectric thin membrane subjected to harmonic forcing from contacting bulk fluids. The key elements of the energy harvester are formulated and characterized, including (i) the mechanical-to-electrical energy conversion efficiency, (ii) the electromechanical shape equation connecting fluid forces with membrane curvature and electric displacement, and (iii) the electric power generation and efficiency. The energy conversion efficiency is cast as the ratio of flexoelectric coupling to the product of electric and bending elasticity. The device is described by a second-order curvature dynamics coupled to the electric displacement equation and as such results in mechanical power absorption with a resonant peak whose amplitude decreases with bending viscosity. The electric power generation is proportional to the conversion factor and the power efficiency decreases with frequency. Under high bending viscosity, the power efficiency increases with the conversion factor and under low viscosities it decreases with the conversion factor. The theoretical results presented contribute to the ongoing experimental efforts to develop mechanical energy harvesting from fluid flow energy through solid-fluid interactions and electromechanical transduction. PMID:23496533

Rey, Alejandro D; Servio, P; Herrera-Valencia, E E

2013-02-19

375

Vibration Energy Harvesting Concept using a Balanced Armature Transducer.  

National Technical Information Service (NTIS)

Balanced armature transducers are used as the speakers in most hearing aids and in some small insert earphones. In this size range, the balanced armature speaker is a more efficient audio generator than other technologies. This project has investigated th...

S. C. Thompson

2012-01-01

376

Piezoelectric, solar and thermal energy harvesting for hybrid low-power generator systems with thin-film batteries  

NASA Astrophysics Data System (ADS)

The harvesting of ambient energy to power small electronic components has received tremendous attention over the last decade. The research goal in this field is to enable self-powered electronic components for use particularly in wireless sensing and measurement applications. Thermal energy due to temperature gradients, solar energy and ambient vibrations constitute some of the major sources of energy that can be harvested. Researchers have presented several papers focusing on each of these topics separately. This paper aims to develop a hybrid power generator and storage system using these three sources of energy in order to improve both structural multifunctionality and system-level robustness in energy harvesting. A multilayer structure with flexible solar, piezoceramic, thin-film battery and metallic substructure layers is developed (with the overhang dimensions of 93 mm × 25 mm × 1.5 mm in cantilevered configuration). Thermal energy is also used for charging the thin-film battery layers using a 30.5 mm × 33 mm × 4.1 mm generator. Performance results are presented for charging and discharging of the thin-film battery layers using each one of the harvesting methods. It is shown based on the extrapolation of a set of measurements that 1 mA h of a thin-film battery can be charged in 20 min using solar energy (for a solar irradiance level of 223 W m-2), in 40 min using thermal energy (for a temperature difference of 31 °C) and in 8 h using vibrational energy (for a harmonic base acceleration input of 0.5g at 56.4 Hz).

Gambier, P.; Anton, S. R.; Kong, N.; Erturk, A.; Inman, D. J.

2012-01-01

377

Structures, systems and methods for harvesting energy from electromagnetic radiation  

DOEpatents

Methods, devices and systems for harvesting energy from electromagnetic radiation are provided including harvesting energy from electromagnetic radiation. In one embodiment, a device includes a substrate and one or more resonance elements disposed in or on the substrate. The resonance elements are configured to have a resonant frequency, for example, in at least one of the infrared, near-infrared and visible light spectra. A layer of conductive material may be disposed over a portion of the substrate to form a ground plane. An optical resonance gap or stand-off layer may be formed between the resonance elements and the ground plane. The optical resonance gap extends a distance between the resonance elements and the layer of conductive material approximately one-quarter wavelength of a wavelength of the at least one resonance element's resonant frequency. At least one energy transfer element may be associated with the at least one resonance element.

Novack, Steven D. (Idaho Falls, ID); Kotter, Dale K. (Shelley, ID); Pinhero, Patrick J. (Columbia, MO)

2011-12-06

378

Adaptive power management in energy harvesting systems  

Microsoft Academic Search

Recently, there has been a substantial interest in the de- sign of systems that receive their energy from regenerative sources such as solar cells. In contrast to approaches that attempt to minimize the power consumption we are con- cerned with adapting parameters of the application such that a maximal utility is obtained while respecting the lim- ited and time-varying amount

Clemens Moser; Lothar Thiele; Davide Brunelli; Luca Benini

2007-01-01

379

Evaluation of energy harvesting performance of electrostrictive polymer and carbon-filled terpolymer composites  

SciTech Connect

Recent trends in energy conversion mechanisms have demonstrated the abilities of electrostrictive polymers for converting mechanical vibrations into electricity. In particular, such materials present advantageous features such as high productivity, high flexibility, and processability. Hence, the application of these materials for energy harvesting purposes has been of significant interest over the last few years. The purpose of this paper consists in evaluating the energy scavenging abilities of electrostrictive terpolymer composite filled with 1 vol % carbon black poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene). For fair comparison, a new figure of merit taking into account the intrinsic parameters of the material is introduced. This figure of merit equals the squared product of the electric field-related electrostrictive coefficient by the Young modulus, divided by the permittivity, relating the electric energy density per cycle per squared strain magnitude and squared bias electric field. Based on this criterion, it is demonstrated that the carbon-filled terpolymer outperforms other investigated compositions, exhibiting a figure of merit as high as 30 mJ cm{sup -3} (m/m){sup -2} (V/{mu}m){sup -2} cycle{sup -1}, which is 2000 times higher than pure polyurethane. In addition, the comparison of the figure of merit with experimental maximal harvested powers shows that such a criterion allows a very accurate prediction of the energy scavenging performance of electrostrictive composites.

Lallart, Mickaeel; Cottinet, Pierre-Jean; Lebrun, Laurent; Guiffard, Benoit; Guyomar, Daniel [Universite de Lyon, INSA-Lyon, LGEF EA 682, 8 rue de la Physique, F-69621 Villeurbanne (France)

2010-08-15

380

Nonmonotonic energy harvesting efficiency in biased exciton chains  

NASA Astrophysics Data System (ADS)

We theoretically study the efficiency of energy harvesting in linear exciton chains with an energy bias, where the initial excitation is taking place at the high-energy end of the chain and the energy is harvested (trapped) at the other end. The efficiency is characterized by means of the average time for the exciton to be trapped after the initial excitation. The exciton transport is treated as the intraband energy relaxation over the states obtained by numerically diagonalizing the Frenkel Hamiltonian that corresponds to the biased chain. The relevant intraband scattering rates are obtained from a linear exciton-phonon interaction. Numerical solution of the Pauli master equation that describes the relaxation and trapping processes reveals a complicated interplay of factors that determine the overall harvesting efficiency. Specifically, if the trapping step is slower than or comparable to the intraband relaxation, this efficiency shows a nonmonotonic dependence on the bias: it first increases when introducing a bias, reaches a maximum at an optimal bias value, and then decreases again because of dynamic (Bloch) localization of the exciton states. Effects of on-site (diagonal) disorder, leading to Anderson localization, are addressed as well.

Vlaming, S. M.; Malyshev, V. A.; Knoester, J.

2007-10-01

381

Improving an energy harvesting device for railroad safety applications  

NASA Astrophysics Data System (ADS)

Due to hundreds of fatalities annually at unprotected railroad crossings (mostly because of collisions with passenger vehicles and derailments resulting from improperly maintained tracks and mechanical failures), supplying a reliable source of electrical energy to power crossing lights and distributed sensor networks is essential to improve safety. With regard to the high cost of electrical infrastructure for railroad crossings in remote areas and the lack of reliability and robustness of solar and wind energy solutions, development of alternative energy harvesting devices is of interest. In this paper, improvements to a mechanical energy harvesting device are presented. The device scavenges electrical energy from deflection of railroad track due to passing railcar traffic. It is mounted to and spans two rail ties and converts and magnifies the track's entire upward and downward displacement into rotational motion of a PMDC generator. The major improvements to the new prototype include: harvesting power from upward displacement in addition to downward, changing the gearing and generator in order to maximize power production capacity for the same shaft speed, and improving the way the system is stabilized for minimizing lost motion. The improved prototype was built, and simulations and tests were conducted to quantify the effects of the improvements.

Pourghodrat, Abolfazl; Nelson, Carl A.; Phillips, Kyle J.; Fateh, Mahmood

2011-03-01

382

Dielectric Elastomers for Actuation and Energy Harvesting  

NASA Astrophysics Data System (ADS)

The first part of this work focuses on free-standing linear soft silicone actuators as this configuration is the most relevant for real applications. A particular soft silicone has been isolated a good candidate and was extensively tested in a free-standing linear actuator configuration to determine the effects of pre-stretch and the application of mechanical loads on its actuation performance. It is shown that when the mechanical loads are properly applied, large linear actuation strains of 120% and work density of 0.5 J/cm3 can be obtained. Furthermore, we demonstrate that when coupled with single wall carbon nanotube (SWNT) compliant electrodes, fault-tolerance is introduced via self-clearing leading to significantly improved operational reliability. Driven at moderate electric fields, the actuators display relatively high linear actuation strain (25%) without degradation of the electromechanical performance even after 85,000 cycles. The high performance of the aforementioned soft silicone actuators requires the application of rather large levels of prestrain. In order to eliminate this requirement a novel all-silicone prestrain-locked interpenetrating polymer network (S-IPN) elastomer was developed. The elastomer is fabricated using a combination of two silicones: a soft room temperature vulcanizing silicone that serves as the host elastomer matrix, and a more rigid high temperature vulcanizing silicone that acts to preserve the prestrain in the host network. The free-standing prestrain-locked silicones show a more than twofold performance improvement over standard free-standing silicone films, with a linear strain of 25% and an area strain of 45% when tested in a diaphragm configuration. The S-IPN procedure was leveraged to improve electrode adhesion and stability as well as improve the interlayer adhesion in multilayer actuators. It is demonstrated that strongly bonded SWNT electrodes are capable of fault tolerance through self-clearing, even in multilayer actuators. The fault-tolerance and improved interlayer adhesion was used to fabricate prestrained free-standing silicone actuators capable of stable long life actuation (>30,000 cycles at >20% strain and >500 cycles at ˜40% strain) while driving a load. Issues related to gradual electrode degradation are also addressed through the use of quasi-buckled electrodes. For generator purposes, the primary concerns are ensuring environmental stability, increasing energy density, lowering losses, and determining effective methods to couple the dielectric elastomer to natural energy sources. Using the results of this analysis, two material systems are explored: VHB acrylic elastomers at various prestrains and with various amounts of a stiffening additive, and a high energy density silicone-TiO2 nanocomposite elastomer with various amounts of additive. It is shown that increasing prestrain in the VHB acrylic system increases the energy density, while the stiffening additive has the effect of making the acrylic stiffer but results in increased losses, result in poorer performance. The silicone TiO2 composite demonstrates an increase in permittivity and stiffness with increasing additive while maintaining very high dielectric breakdown strength values. These increases are partially offset by small increases in mechanical and electrical losses. Calculations based on a simple model show that the generator energy density can be improved by a factor of 3 for a 20wt.% TiO2 loading at a strain of 50% in area. The calculated generator energy density values exceed the maximum values measured experimentally for highly prestrained VHB4910 acrylic elastomers. The focus on high energy density materials ignores the fact that not all applications require such a material, and that some applications may, in fact, benefit from the use of a softer material that is less intrusive. However, for lower energy density materials, parasitic losses due to electrode resistance and viscoelasticity play a larger role as relative energy gains are lower. With this is mind, a soft silicone sing

Brochu, Paul A.

383

Feasibility of Energy Harvesting Using a Piezoelectric Tire  

NASA Astrophysics Data System (ADS)

While the piezoelectric effect has been around for some time, it has only recently caught interest as a potential sustainable energy harvesting device. Piezoelectric energy harvesting has been developed for shoes and panels, but has yet to be integrated into a marketable bicycle tire. For this thesis, the development and feasibility of a piezoelectric tire was done. This includes the development of a circuit that incorporates piezoceramic elements, energy harvesting circuitry, and an energy storage device. A single phase circuit was designed using an ac-dc diode rectifier. An electrolytic capacitor was used as the energy storage device. A financial feasibility was also done to determine targets for manufacturing cost and sales price. These models take into account market trends for high performance tires, economies of scale, and the possibility of government subsidies. This research will help understand the potential for the marketability of a piezoelectric energy harvesting tire that can create electricity for remote use. This study found that there are many obstacles that must be addressed before a piezoelectric tire can be marketed to the general public. The power output of this device is minuscule compared to an alkaline battery. In order for this device to approach the power output of an alkaline battery the weight of the device would also become an issue. Additionally this device is very costly compared to the average bicycle tire. Lastly, this device is extreme fragile and easily broken. In order for this device to become marketable the issues of power output, cost, weight, and durability must all be successfully overcome.

Malotte, Christopher

384

Upper bounds for energy harvesting in the region of the human head.  

PubMed

This paper investigates different approaches for supplying power to implantable hearing systems via energy harvesting. Because of the specific nature of the problem, only energy harvesting in the region of the human head is considered. Upper bounds as well as more conservative estimations for harvesting mechanical, thermal, and electromagnetic energy are presented and discussed. PMID:21813361

Goll, Erich; Zenner, Hans-Peter; Dalhoff, Ernst

2011-08-01

385

Production, Delivery and Application of Vibration Energy in Healthcare  

NASA Astrophysics Data System (ADS)

In Rehabilitation Medicine therapeutic application of vibration energy in specific clinical treatments and in sport rehabilitation is being affirmed more and more.Vibration exposure can have positive or negative effects on the human body depending on the features and time of the characterizing wave. The human body is constantly subjected to different kinds of vibrations, inducing bones and muscles to actively modify their structure and metabolism in order to fulfill the required functions. Like every other machine, the body supports only certain vibration energy levels over which long term impairments can be recognized. As shown in literature anyway, short periods of vibration exposure and specific frequency values can determine positive adjustments.

Abundo, Paolo; Trombetta, Chiara; Foti, Calogero; Rosato, Nicola

2011-02-01

386

Light energy harvesting with nano-dipoles.  

PubMed

We propose a new approach for converting light energy into electrical energy, based on the photogeneration of nano-dipoles at donor-acceptor interfaces. The nano-dipoles are oriented in space so as to contribute to a collective polarization that induces a potential difference across the material, sandwiched between electrodes. A current is detected in the external circuit upon illumination. Such a device would exploit many advantages of organic semiconductors and get rid of the main limitation, namely transport. We provide a proof of concept and we discuss the ideal limit of the device based on numerical simulations. This provides design guidelines to the achievement of best performances. Simulations show that the proposed device can be an appealing opportunity with giant conversion efficiency provided some technological issues are overcome. PMID:22297323

Garbugli, Michele; Porro, Matteo; Roiati, Vittoria; Rizzo, Aurora; Gigli, Giuseppe; Petrozza, Annamaria; Lanzani, Guglielmo

2012-02-01

387

Statistically linearized optimal control of an electromagnetic vibratory energy harvester  

NASA Astrophysics Data System (ADS)

In this paper, an extension of linear-quadratic-Gaussian (LQG) control theory is used to determine the optimal state feedback controller for a vibratory energy harvesting system with Coulomb friction. Specifically, the energy harvester is a base-excited single-degree-of-freedom (SDOF) resonant oscillator with an electromagnetic transducer attached between the base and the moving mass. The development of the optimal controller for this system is based on statistical linearization, whereby the Coulomb friction force is replaced by an equivalent linear viscous damping term, which is calculated from the stationary covariance of the closed-loop system. It is shown that the covariance matrix and optimal feedback gain matrix can be computed by implementing an iterative algorithm involving linear matrix inequalities (LMIs). Furthermore, this theory is augmented to account for a non-quadratic dissipation in the electronics used to control the energy conversion. Simulation results are presented for the SDOF energy harvester in which the performance of the optimal state feedback control law is compared to the performance of the optimal static admittance over a range of disturbance bandwidths.

Cassidy, Ian L.; Scruggs, Jeffrey T.

2012-08-01

388

The pizzicato knee-joint energy harvester: characterization with biomechanical data and the effect of backpack load  

NASA Astrophysics Data System (ADS)

The reduced power requirements of miniaturized electronics offer the opportunity to create devices which rely on energy harvesters for their power supply. In the case of wearable devices, human-based piezoelectric energy harvesting is particularly difficult due to the mismatch between the low frequency of human activities and the high-frequency requirements of piezoelectric transducers. We propose a piezoelectric energy harvester, to be worn on the knee-joint, that relies on the plucking technique to achieve frequency up-conversion. During a plucking action, a piezoelectric bimorph is deflected by a plectrum; when released due to loss of contact, the bimorph is free to vibrate at its resonant frequency, generating electrical energy with the highest efficiency. A prototype, featuring four PZT-5H bimorphs, was built and is here studied in a knee simulator which reproduces the gait of a human subject. Biomechanical data were collected with a marker-based motion capture system while the subject was carrying a selection of backpack loads. The paper focuses on the energy generation of the harvester and how this is affected by the backpack load. By altering the gait, the backpack load has a measurable effect on performance: at the highest load of 24 kg, a minor reduction in energy generation (7%) was observed and the output power is reduced by 10%. Both are so moderate to be practically unimportant. The average power output of the prototype is 2.06 ± 0.3 mW, which can increase significantly with further optimization.

Pozzi, Michele; Aung, Min S. H.; Zhu, Meiling; Jones, Richard K.; Goulermas, John Y.

2012-07-01

389

The vibrational energy levels of ammonia  

NASA Astrophysics Data System (ADS)

A variational 6-dimensional method is used to determine the low lying vibrational energy levels of ammonia. The six internal coordinates were chosen to be appropriate for the symmetry and inversion motion of the molecule; they were the three NH bond lengths, r1,r2,r3, the unique angle beta which each bond makes with the trisector of them, and two (of the three) angles, theta2 and theta3, between the bonds when projected on to a plane perpendicular to the trisector. The Wilson G matrix was determined for these internal coordinates both by computer algebra and by hand. An appropriate Jacobian for the motion was determined and the full Hermitian kinetic energy operator was obtained using the Podolsky transformation. Expansion functions were in the usual product form. Special attention was given to the , theta2,theta3 expansion functions so that appropriate A1,A2 and E symmetry vibrational modes were obtained explicitly. Matrix elements of the kinetic energy operator were expressed in terms of one-dimensional integrals. Variational calculations have been performed with two six-dimensional surfaces: (i) that due to Martin, Lee and Taylor; and (ii) that due to Spirko and Kraemer. Although some of the vibrational levels for both surfaces are accurate, both have inadequacies: (a) because it is a Taylor expansion about an equilibrium, based on ab initio calculations, with no attention paid to planarity; and (b) because the non-inversion part of the surface was treated perturbatively in its derivation, and in fact some of the quartic displacement powers have negative coefficients. Therefore, neither surface gave good results overall, and there is a need for a refined 6 dimensional NH surface.

Handy, Nicholas C.

1999-02-01

390

Design and testing of piezoelectric energy harvester for powering wireless sensors of electric line monitoring system  

NASA Astrophysics Data System (ADS)

Scavenging electromagnetic and vibration energy from environments is an attractive technique for powering wireless sensors in a wireless sensor network. This paper reports our design and testing results on the electric output performance of a piezoelectric energy harvesting device, which consists of cantilever beams, magnetoelectric (ME) transducers, and permanent magnets. The geometric parameters of the device are based on an optimization design with a targeted resonant frequency of 50 Hz. Experimental results show that an output voltage of 56.1 V and an average power of 0.24 mW are achieved responding to a current of 3 A at 50 Hz. Remarkably, this power is a very encouraging power figure that gives the prospect of being able to power a wide range of wireless sensors in an electric line monitoring system.

Qiu, Jing; Wen, Yumei; Li, Ping; Yang, Jin

2012-04-01

391

A non-ideal portal frame energy harvester controlled using a pendulum  

NASA Astrophysics Data System (ADS)

A model of energy harvester based on a simple portal frame structure is presented. The system is considered to be non-ideal system (NIS) due to interaction with the energy source, a DC motor with limited power supply and the system structure. The nonlinearities present in the piezoelectric material are considered in the piezoelectric coupling mathematical model. The system is a bi-stable Duffing oscillator presenting a chaotic behavior. Analyzing the average power variation, and bifurcation diagrams, the value of the control variable that optimizes power or average value that stabilizes the chaotic system in the periodic orbit is determined. The control sensitivity is determined to parametric errors in the damping and stiffness parameters of the portal frame. The proposed passive control technique uses a simple pendulum to tuned to the vibration of the structure to improve the energy harvesting. The results show that with the implementation of the control strategy it is possible to eliminate the need for active or semi active control, usually more complex. The control also provides a way to regulate the energy captured to a desired operating frequency.

Iliuk, I.; Balthazar, J. M.; Tusset, A. M.; Piqueira, J. R. C.; Rodrigues de Pontes, B.; Felix, J. L. P.; Bueno, Á. M.

2013-09-01

392

Design of piezoelectric sensors, actuators, and energy harvesting devices using topology optimization  

NASA Astrophysics Data System (ADS)

Sensors and actuators based on piezoelectric plates have shown increasing demand in the field of smart structures, including the development of actuators for cooling and fluid pumping applications and transducers for novel energy harvesting devices. This project involves the development of a finite element and topology optimization software to design piezoelectric sensors, actuators and energy harvesting devices by distributing piezoelectric material over a metallic plate in order to achieve a desired dynamic behavior with specified vibration frequencies. The finite element employs a general formulation capable of representing both direct and converse piezoelectric effects. It is based on the MITC formulation, which is reliable, efficient and avoids the shear locking problem. The topology optimization formulation is based on the PEMAP-P model (Piezoelectric Material with Penalization and Polarization), where the design variables are the pseudo-densities that describe the amount of piezoelectric material at each finite element. The optimization problem has a multi-objective function, which can be subdivided into three distinct problems: maximization of mean transduction, minimization of mean compliance and optimization of Eigenvalues. The first one is responsible for maximizing the amount of electric energy converted into elastic energy, the second one guarantees that the structure does not become excessively flexible and the third one tunes the structure for a given frequency. This paper presents the implementation of the finite element and optimization software and shows preliminary results achieved.

Nakasone, Paulo H.; Kiyono, César Y.; Silva, Emílio C. N.

2008-05-01

393

Piezoelectric energy harvester having planform-tapered interdigitated beams  

DOEpatents

Embodiments of energy harvesters have a plurality of piezoelectric planform-tapered, interdigitated cantilevered beams anchored to a common frame. The plurality of beams can be arranged as two or more sets of beams with each set sharing a common sense mass affixed to their free ends. Each set thus defined being capable of motion independent of any other set of beams. Each beam can comprise a unimorph or bimorph piezoelectric configuration bonded to a conductive or non-conductive supporting layer and provided with electrical contacts to the active piezoelectric elements for collecting strain induced charge (i.e. energy). The beams are planform tapered along the entirety or a portion of their length thereby increasing the effective stress level and power output of each piezoelectric element, and are interdigitated by sets to increase the power output per unit volume of a harvester thus produced.

Kellogg, Rick A. (Tijeras, NM); Sumali, Hartono (Albuquerque, NM)

2011-05-24

394

IPMC as a mechanoelectric energy harvester: tailored properties  

NASA Astrophysics Data System (ADS)

Due to their inherited mechanoelectric transduction capability, long-life, and effective operation in both air and water, ionic polymer-metal composites (IPMCs) are considered for energy harvesting applications. The reported research aims to study different parameters in the mechanical domain (stiffness and scalability) and the electrical domain (impedance and interfacial area) that seem to have profound effects on battery charging, with the aid of an electromechanical transducer model (Tiwari et al 2008 Smart Struct. Syst. 4 549-3). Experiments performed to confirm the model predictions are also reported. The research demonstrates the applicability of IPMC as an energy harvester in lower frequency regions (<50 Hz) with an average efficiency of around 2% or less. The instantaneous power output from 10 mm (width)×50 mm (length)×0.2 mm (thickness) was measured to be approximately 4 ?W (20 W m-3).

Tiwari, R.; Kim, K. J.

2013-01-01

395

Self powered sensing by combining novel sensor architectures with energy harvesting  

NASA Astrophysics Data System (ADS)

The sensing techniques investigated in this thesis utilize piezoelectric materials, piezoresistive materials, and magnetoelectric composites. Prior studies on structural health monitoring have demonstrated the use and promise of piezoelectric sensors. In this research, impedance spectroscopy based sensing technique was investigated with respect to two parameters (i) effect of the piezoelectric vibration mode on damage index metric, and (ii) selection of frequency band through manipulation of the electrode size and shape. These results were then used to determine sensor geometry and dimensions for detecting surface defects, fatigue and corrosion. Based upon these results, power requirement for structural health monitoring sensors was determined. Next, piezoelectric materials were coupled with magnetostrictive material for novel magnetic field gradient sensing. The ceramic -- ceramic (CC) gradiometer resembles in functionality a magnetoelectric transformer. It measures the magnetic field gradient and sensitivity with respect to a reference value. The CC gradiometer designed in this study was based upon the magnetoelectric (ME) composites and utilizes the ring-dot piezoelectric transformer structure working near resonance as the basis. This study investigated the gradiometer design and characterized the performance of gradiometer based upon Terfenol--D -- PZT composites. Based upon these results, next a metal -- ceramic gradiometer consisting of PZT and nickel was designed and characterized. In this thesis, two different designs of gradiometer with nickel and PZT laminate composites were fabricated. Nickel was chosen over other materials considering its co-firing ability with PZT. It can give a better control over dimensional parameters of the gradiometer sample and further size reduction is possible with tape casting technique. Detailed theoretical analysis was conducted in order to understand the experimental results. In order to significantly reduce the power consumption of health monitoring and magnetic field sensors, bottom -- up design of structural health monitoring and magnetic field sensors was investigated. A MWCNT/SiCN nanotube template was developed that exhibits piezoresistive effect. Next, a novel nanotube morphology "nanoNecklace" was synthesized that consists of BaTiO 3 (BTO) nanoparticles decorated along the surface of SiCN. Monolayer coating of SiCN on MWCNT serves two purposes: (i) modifies the surface wetting characteristics, and (ii) enhances the piezoresistive effect. Investigation of the mechanisms that provide periodic arrangement of BTO on nanotube surface was conducted using HRTEM and contact angle measurements. Next, we tried to modify the surface wetting characteristics of MWCNTs in order to get a full coating of BTO nanoparticles. The SiCN/MWCNT approach was further extended to fabricate magnetoelectric nanowire based sensors designs. In this approach a SiCN-NT template was coated with BTO and CoFe2O4 (CFO) nanoparticles. Microstructural studies indicated the presence of piezoelectric (BTO) as well as magnetic (CFO) material on the nanotube surface. In order to power the sensors from mechanical vibrations, we investigated two different techniques, (i) piezoelectric and (ii) inductive. An analytical model for energy harvesting from bimorph transducer was developed which was confirmed by experimental measurements. The results show that power density of bimorph transducer can be enhanced by increasing the magnitude of product (d.g), where d is the piezoelectric strain constant and g is the piezoelectric voltage constant. Under inductive energy harvesting, we designed and fabricated a small scale harvester that was integrated inside a pen commonly carried by humans to harvest vibration energy. Inductive energy harvesting was selected in order to achieve high power at lower frequencies. The prototype cylindrical harvester was found to generate 3mW at 5 Hz and 1mW at 3.5 Hz operating under displacement amplitude of 16mm (corresponding to an acceleration of approximately 1.14 grms at 5Hz and

Bedekar, Vishwas Narayan

396

Energy Harvesting for Electronics with Thermoelectric Devices using Nanoscale Materials  

Microsoft Academic Search

Significant developments have occurred in the last few years in the area of nanoscale thermoelectric materials using superlattices and self-assembled quantum-dots. Thin-film thermoelectric (TE) devices employing these materials have been developed for many applications including energy harvesting. Thin-film TE devices, for a 1 mm3 of converter volume, are available that can produce well over 775 muW\\/mm3 with an external DeltaT

R. Venkatasubramanian; C. Watkins; D. Stokes; J. Posthill; C. Caylor

2007-01-01

397

Unconventional wearable energy harvesting from human horizontal foot motion  

Microsoft Academic Search

This paper presents an unconventional flat-type linear permanent magnetic generator based energy harvesting system which employs a cascaded boost-buck two-stage converter, with a maximum power control algorithm optimized for low frequency human horizontal foot motion, for Li-Ion battery charging. The dynamic model of the linear generator is built and the analytical equations for maximum power generation of non- resonant applications

Peng Zeng; Hao Chen; Zhi Yang; Alireza Khaligh

2011-01-01

398

Design and analysis of an unconventional permanent magnet linear machine for energy harvesting  

NASA Astrophysics Data System (ADS)

This Ph.D. dissertation proposes an unconventional high power density linear electromagnetic kinetic energy harvester, and a high-performance two-stage interface power electronics to maintain maximum power abstraction from the energy source and charge the Li-ion battery load with constant current. The proposed machine architecture is composed of a double-sided flat type silicon steel stator with winding slots, a permanent magnet mover, coil windings, a linear motion guide and an adjustable spring bearing. The unconventional design of the machine is that NdFeB magnet bars in the mover are placed with magnetic fields in horizontal direction instead of vertical direction and the same magnetic poles are facing each other. The derived magnetic equivalent circuit model proves the average air-gap flux density of the novel topology is as high as 0.73 T with 17.7% improvement over that of the conventional topology at the given geometric dimensions of the proof-of-concept machine. Subsequently, the improved output voltage and power are achieved. The dynamic model of the linear generator is also developed, and the analytical equations of output maximum power are derived for the case of driving vibration with amplitude that is equal, smaller and larger than the relative displacement between the mover and the stator of the machine respectively. Furthermore, the finite element analysis (FEA) model has been simulated to prove the derived analytical results and the improved power generation capability. Also, an optimization framework is explored to extend to the multi-Degree-of-Freedom (n-DOF) vibration based linear energy harvesting devices. Moreover, a boost-buck cascaded switch mode converter with current controller is designed to extract the maximum power from the harvester and charge the Li-ion battery with trickle current. Meanwhile, a maximum power point tracking (MPPT) algorithm is proposed and optimized for low frequency driving vibrations. Finally, a proof-of-concept unconventional permanent magnet (PM) linear generator is prototyped and tested to verify the simulation results of the FEA model. For the coil windings of 33, 66 and 165 turns, the output power of the machine is tested to have the output power of 65.6 mW, 189.1 mW, and 497.7 mW respectively with the maximum power density of 2.486 mW/cm3.

Zeng, Peng

399

Low power energy harvesting and storage techniques from ambient human powered energy sources  

NASA Astrophysics Data System (ADS)

Conventional electrochemical batteries power most of the portable and wireless electronic devices that are operated by electric power. In the past few years, electrochemical batteries and energy storage devices have improved significantly. However, this progress has not been able to keep up with the development of microprocessors, memory storage, and sensors of electronic applications. Battery weight, lifespan and reliability often limit the abilities and the range of such applications of battery powered devices. These conventional devices were designed to be powered with batteries as required, but did not allow scavenging of ambient energy as a power source. In contrast, development in wireless technology and other electronic components are constantly reducing the power and energy needed by many applications. If energy requirements of electronic components decline reasonably, then ambient energy scavenging and conversion could become a viable source of power for many applications. Ambient energy sources can be then considered and used to replace batteries in some electronic applications, to minimize product maintenance and operating cost. The potential ability to satisfy overall power and energy requirements of an application using ambient energy can eliminate some constraints related to conventional power supplies. Also power scavenging may enable electronic devices to be completely self-sustaining so that battery maintenance can eventually be eliminated. Furthermore, ambient energy scavenging could extend the performance and the lifetime of the MEMS (Micro electromechanical systems) and portable electronic devices. These possibilities show that it is important to examine the effectiveness of ambient energy as a source of power. Until recently, only little use has been made of ambient energy resources, especially for wireless networks and portable power devices. Recently, researchers have performed several studies in alternative energy sources that could provide small amounts of electricity to low-power electronic devices. These studies were focused to investigate and obtain power from different energy sources, such as vibration, light, sound, airflow, heat, waste mechanical energy and temperature variations. This research studied forms of ambient energy sources such as waste mechanical (rotational) energy from hydraulic door closers, and fitness exercise bicycles, and its conversion and storage into usable electrical energy. In both of these examples of applications, hydraulic door closers and fitness exercise bicycles, human presence is required. A person has to open the door in order for the hydraulic door closer mechanism to function. Fitness exercise bicycles need somebody to cycle the pedals to generate electricity (while burning calories.) Also vibrations, body motions, and compressions from human interactions were studied using small piezoelectric fiber composites which are capable of recovering waste mechanical energy and converting it to useful electrical energy. Based on ambient energy sources, electrical energy conversion and storage circuits were designed and tested for low power electronic applications. These sources were characterized according to energy harvesting (scavenging) methods, and power and energy density. At the end of the study, the ambient energy sources were matched with possible electronic applications as a viable energy source.

Yildiz, Faruk

400

An investigation into active piezoelectric nanocomposites for distributed energy harvesting  

NASA Astrophysics Data System (ADS)

The use of monolithic piezoceramic materials in sensing and actuation applications has become quite common over the past decade. However, these materials have several properties that limit their application in practical systems. These materials are very brittle due to the ceramic nature of the monolithic material, making them vulnerable to accidental breakage during handling and bonding procedures. In addition, they have very poor ability to conform to curved surfaces and result in large add-on mass associated with using a typically lead-based ceramic. These limitations have motivated the development of alternative methods of applying the piezoceramic material, including piezoceramic fiber composites (PFCs), and piezoelectric paints. Piezoelectric paint is desirable because it can be spayed or painted on and can be used with abnormal surfaces. The ease at which the active composite can be applied allows for far larger surfaces to be used for energy harvesting than can be achieved with typical materials. Developments in piezoelectric nanocomposites for energy harvesting will also allow for the development of compliant materials with electromechanical coupling greater than available through existing piezoelectric polymers such as polyvinylidene floride (PVDF). Furthermore, the application of PVDF is limited to thin films due to the straining process required to obtain piezoelectric phase of the material. However, active nanocomposites can be molded into geometries that could not be obtained using currently available materials. The present study will characterize a variety of piezoelectric nanocomposite materials to determine how the properties of the polymer matrix and the piezoelectric inclusion affect the energy harvesting performance. The resulting active nanocomposites will be compared to existing piezo-polymers for power harvesting.

Liu, Yingtao; Sodano, Henry A.

2008-05-01

401

Low Head, Vortex Induced Vibrations River Energy Converter  

Microsoft Academic Search

Vortex Induced Vibrations Aquatic Clean Energy (VIVACE) is a novel, demonstrated approach to extracting energy from water currents. This invention is based on a phenomenon called Vortex Induced Vibrations (VIV), which was first observed by Leonardo da Vinci in 1504AD. He called it âAeolian Tones.â For decades, engineers have attempted to prevent this type of vibration from damaging structures, such

Michael B. Bernitsas; Tad Dritz

2006-01-01

402

Frequency up-converted wide bandwidth piezoelectric energy harvester using mechanical impact  

NASA Astrophysics Data System (ADS)

This paper presents an impact based frequency up-converted wide bandwidth piezoelectric energy harvester in which two high frequency piezoelectric generating beams are struck at the same time by a low frequency driving beam having horizontally extended tip mass. Change of driving beam's effective stiffness during coupled vibration after impact allows the device to broaden the -3dB bandwidth to approximately 170% and to acquire more than 61% of the maximum power generation in the vicinity (from 7 to 10.5 Hz) of the -3 dB bandwidth region as well. The efficiency of electrical power transfer is increased to approximately 85%. Each generating beam produces 377 ?W peak power at 14.5 Hz under 0.6 g acceleration with corresponding power density 58.8 ?W cm-3.

Halim, Miah A.; Khym, S.; Park, J. Y.

2013-07-01

403

Vibrational Population Depletion in Thermal Dissociation for Nonequilibrium Energy Distribution  

NASA Astrophysics Data System (ADS)

The generalized depletion equations, considering state-to-state kinetics of dissociating Nitrogen, are solved to predict the extent of vibrational depletion in the temperature range of 3000-10000 K. For the case of dissociation from the last vibrational quantum level, depletion of vibrational population is high. Vibration-translation (V-T) energy transfers make a major contribution to depletion whereas the effect of vibration-vibration (V-V) exchanges is minor. The dissociation rates predicted using the vibration-dissociation coupling model are significantly lower than the Park's rates and helps explain the restricted success of the Park's dissociation model in certain temperature ranges of hypersonic flow past a blunt body. Underprediction of shock-standoff distance of 17% by Park dissociation model for a Mach 11.18 flow past a blunt body is predicted well by the present model.

Josyula, Eswar; Bailey, William F.

2003-05-01

404

Enhanced aeroelastic energy harvesting by exploiting combined nonlinearities: theory and experiment  

NASA Astrophysics Data System (ADS)

Converting aeroelastic vibrations into electricity for low power generation has received growing attention over the past few years. In addition to potential applications for aerospace structures, the goal is to develop alternative and scalable configurations for wind energy harvesting to use in wireless electronic systems. This paper presents modeling and experiments of aeroelastic energy harvesting using piezoelectric transduction with a focus on exploiting combined nonlinearities. An airfoil with plunge and pitch degrees of freedom (DOF) is investigated. Piezoelectric coupling is introduced to the plunge DOF while nonlinearities are introduced through the pitch DOF. A state-space model is presented and employed for the simulations of the piezoaeroelastic generator. A two-state approximation to Theodorsen aerodynamics is used in order to determine the unsteady aerodynamic loads. Three case studies are presented. First the interaction between piezoelectric power generation and linear aeroelastic behavior of a typical section is investigated for a set of resistive loads. Model predictions are compared to experimental data obtained from the wind tunnel tests at the flutter boundary. In the second case study, free play nonlinearity is added to the pitch DOF and it is shown that nonlinear limit-cycle oscillations can be obtained not only above but also below the linear flutter speed. The experimental results are successfully predicted by the model simulations. Finally, the combination of cubic hardening stiffness and free play nonlinearities is considered in the pitch DOF. The nonlinear piezoaeroelastic response is investigated for different values of the nonlinear-to-linear stiffness ratio. The free play nonlinearity reduces the cut-in speed while the hardening stiffness helps in obtaining persistent oscillations of acceptable amplitude over a wider range of airflow speeds. Such nonlinearities can be introduced to aeroelastic energy harvesters (exploiting piezoelectric or other transduction mechanisms) for performance enhancement.

Sousa, V. C.; Anicézio, M. de M.; De Marqui, C., Jr.; Erturk, A.

2011-09-01

405

The potential for harvesting energy from the movement of trees.  

PubMed

Over the last decade, wireless devices have decreased in size and power requirements. These devices generally use batteries as a power source but can employ additional means of power, such as solar, thermal or wind energy. However, sensor networks are often deployed in conditions of minimal lighting and thermal gradient such as densely wooded environments, where even normal wind energy harvesting is limited. In these cases a possible source of energy is from the motion of the trees themselves. We investigated the amount of energy and power available from the motion of a tree in a sheltered position, during Beaufort 4 winds. We measured the work performed by the tree to lift a mass, we measured horizontal acceleration of free movement, and we determined the angular deflection of the movement of the tree trunk, to determine the energy and power available to various types of harvesting devices. We found that the amount of power available from the tree, as demonstrated by lifting a mass, compares favourably with the power required to run a wireless sensor node. PMID:22163695

McGarry, Scott; Knight, Chris

2011-09-28

406

Feasibility of energy harvesting for powering wireless sensors in transportation infrastructure applications  

NASA Astrophysics Data System (ADS)

In recent years, wireless sensors technologies are attracted many researchers in the field of structural health monitoring (SHM) of civil, mechanical and aerospace systems. Another potential application of wireless sensors is in the Vehicle-Infrastructure Integration (VII) which is an initiative by the U.S. Department of Transportation to improve road safety and reduce congestion, through as part of its Intelligent Transportation System program. However, fundamental issues remain unresolved before a broad application of the wireless SHM or VII sensor network concept is the question of sustainable power source for each independent sensor mounted on infrastructures. With a vast number of sensors nodes/networks in the infrastructure, connecting them to the grid power source is simply uneconomical in the era of wireless technology. The other option, which is providing power to each sensor from battery sources, has its own setbacks, as batteries can only provide power for a limited period, have to be replaced periodically (often difficult and costly), and their disposal creates environmental hazard. This study addresses the feasibility of energy harvesting from the ambient vibration of transportation infrastructures to power wireless sensors. Based on the vibration responses from simulation and field tests, vehicle induced vibrations on bridge and pavement were obtained and the theoretical power output from such vibration sources were computed. The expected results from this study will be demonstrated by avoiding complex wiring to the sensors by which the associated cost of wiring and batteries will be significantly reduced, and at the same time the technology can easily be deployed, meaning it is one step forward in improving the SHM and VII applications.

Ashebo, Demeke Beyene; Tan, Chin An; Wang, Jun; Li, Gang

2008-04-01

407

Fabrication and characterization of free-standing thick-film piezoelectric cantilevers for energy harvesting  

NASA Astrophysics Data System (ADS)

Research into energy harvesting from ambient vibration sources has attracted great interest over the last few years, largely as a result of advances in the areas of wireless technology and low-power electronics. One of the mechanisms for converting mechanical vibration to electrical energy is the use of piezoelectric materials, typically operating as a cantilever in a bending mode, which generate a voltage across the electrodes when they are stressed. Typically, the piezoelectric materials are deposited on a non-electro-active substrate and are physically clamped at one end to a rigid base. The presence of the substrate does not contribute directly to the electrical output, but merely serves as a mechanical supporting platform, which can pose difficulties for integration with other microelectronic devices. The aim of this paper is to describe a novel thick-film free-standing cantilever structure that does not use a supporting platform and has the advantage of minimizing the movement constraints on the piezoelectric material, thereby maximizing the electrical output power. Two configurations of the composite cantilever structure were investigated: unimorph and multimorph. A unimorph consists of a pair of silver/palladium (Ag/Pd) electrodes sandwiching a laminar layer of lead zirconate titanate (PZT). A mulitmorph is an extended version of the unimorph with two pairs of Ag/Pd electrodes and three laminar sections of PZT.

Kok, Swee-Leong; White, Neil M.; Harris, Nick R.

2009-12-01

408

Bio-kinetic energy harvesting using electroactive polymers  

NASA Astrophysics Data System (ADS)

In hybrid vehicles, electric motors are used on each wheel to not only propel the car but also to decelerate the car by acting as generators. In the case of the human body, muscles spend about half of their time acting as a brake, absorbing energy, or doing what is known as negative work. Using dielectric elastomers it is possible to use the "braking" phases of walking to generate power without restricting or fatiguing the Warfighter. Infoscitex and SRI have developed and demonstrated methods for using electroactive polymers (EAPs) to tap into the negative work generated at the knee during the deceleration phase of the human gait cycle and convert it into electrical power that can be used to support wearable information systems, including display and communication technologies. The specific class of EAP that has been selected for these applications is termed dielectric elastomers. Because dielectric elastomers dissipate very little mechanical energy into heat, greater amounts of energy can be converted into electricity than by any other method. The long term vision of this concept is to have EAP energy harvesting cells located in components of the Warfighter ensemble, such as the boot uppers, knee pads and eventually even the clothing itself. By properly locating EAPs at these sites it will be possible to not only harvest power from the negative work phase but to actually reduce the amount of work done by the Warfighter's muscles during this phase, thereby reducing fatigue and minimizing the forces transmitted to the joints.

Slade, Jeremiah R.; Bowman, Jeremy; Kornbluh, Roy

2012-05-01

409

Wireless Compressive Sensing for Energy Harvesting Sensor Nodes  

NASA Astrophysics Data System (ADS)

We consider the scenario in which multiple sensors send spatially correlated data to a fusion center (FC) via independent Rayleigh-fading channels with additive noise. Assuming that the sensor data is sparse in some basis, we show that the recovery of this sparse signal can be formulated as a compressive sensing (CS) problem. To model the scenario in which the sensors operate with intermittently available energy that is harvested from the environment, we propose that each sensor transmits independently with some probability, and adapts the transmit power to its harvested energy. Due to the probabilistic transmissions, the elements of the equivalent sensing matrix are not Gaussian. Besides, since the sensors have different energy harvesting rates and different sensor-to-FC distances, the FC has different receive signal-to-noise ratios (SNRs) for each sensor. This is referred to as the inhomogeneity of SNRs. Thus, the elements of the sensing matrix are also not identically distributed. For this unconventional setting, we provide theoretical guarantees on the number of measurements for reliable and computationally efficient recovery, by showing that the sensing matrix satisfies the restricted isometry property (RIP), under reasonable conditions. We then compute an achievable system delay under an allowable mean-squared-error (MSE). Furthermore, using techniques from large deviations theory, we analyze the impact of inhomogeneity of SNRs on the so-called k-restricted eigenvalues, which governs the number of measurements required for the RIP to hold. We conclude that the number of measurements required for the RIP is not sensitive to the inhomogeneity of SNRs, when the number of sensors n is large and the sparsity of the sensor data (signal) k grows slower than the square root of n. Our analysis is corroborated by extensive numerical results.

Yang, Gang; Tan, Vincent Y. F.; Ho, Chin Keong; Ting, See Ho; Guan, Yong Liang

2013-09-01

410

An improved analysis of the SSHI interface in piezoelectric energy harvesting  

Microsoft Academic Search

This paper provides an analysis for the performance evaluation of a piezoelectric energy harvesting system using the synchronized switch harvesting on inductor (SSHI) electronic interface. In contrast with estimates based on a variety of approximations in the literature, an analytic expression of harvested power is derived explicitly and validated numerically for the SSHI system. It is shown that the electrical

Y C Shu; I C Lien; W J Wu

2007-01-01

411

On the energy harvesting potential of piezoaeroelastic systems  

NASA Astrophysics Data System (ADS)

This paper investigates the concept of piezoaeroelasticity for energy harvesting. The focus is placed on mathematical modeling and experimental validations of the problem of generating electricity at the flutter boundary of a piezoaeroelastic airfoil. An electrical power output of 10.7 mW is delivered to a 100 k? load at the linear flutter speed of 9.30 m/s (which is 5.1% larger than the short-circuit flutter speed). The effect of piezoelectric power generation on the linear flutter speed is also discussed and a useful consequence of having nonlinearities in the system is addressed.

Erturk, A.; Vieira, W. G. R.; de Marqui, C.; Inman, D. J.

2010-05-01

412

Forest Fuel Reduction Through Energy Wood Production Using a Small Chipper\\/CTL Harvesting System  

Microsoft Academic Search

In the summer of 2000, fire destroyed millions of acres of forest across the United States. This study investigates the feasibility of harvesting to reduce forest fuel buildup and produce energy wood. Cut-to-length (CTL) harvesting coupled with a small in-woods chipper provides a low impact way to harvest pre-commercial trees and tops along with merchantable logs. While CTL harvesting systems

M. Chad Bolding; Bobby L. Lanford

413

Electromechanical fatigue in IPMC under dynamic energy harvesting conditions  

NASA Astrophysics Data System (ADS)

Ionic polymer-metal composites (IPMCs) are an interesting subset of smart, multi-functional materials that have shown promises in energy conversion technologies. Being electromechanically coupled, IPMCs can function as dynamic actuators and sensors, transducers for energy conversion and harvesting, as well as artificial muscles for medical and industrial applications. Like all natural materials, even IPMCs undergo fatigue under dynamic load conditions. Here, we investigate the electromechanical fatigue induced in the IPMCs due to the application of cyclic mechanical bending deformation under hydrodynamic energy harvesting condition. Considering the viscoelastic nature of the IPMC, we employ an analytical approach to modeling electromechanical fatigue primarily under the cyclic stresses induced in the membrane. The polymer-metal composite undergoes cyclic softening throughout the fatigue life without attaining a saturated state of charge migration. However, it results in (1) degradation of electromechanical performance; (2) nucleation and growth of microscopic cracks in the metal electrodes; (3) delamination of metal electrodes at the polymer-electrode interface. To understand these processes, we employ a phenomenological approach based on experimentally measured relaxation properties of the IPMC membrane. Electromechanical performance improves significantly with self-healing like properties for a certain range of relaxation time. This is due to reorientation of the backbone polymer chains which eventually leads to a regenerative process with increased charge transport.

Krishnaswamy, Arvind; Roy Mahapatra, D.

2011-03-01

414

AmbiMax: Autonomous Energy Harvesting Platform for Multi-Supply Wireless Sensor Nodes  

Microsoft Academic Search

AmbiMax is an energy harvesting circuit and a supercapacitor based energy storage system for wireless sensor nodes (WSN). Previous WSNs attempt to harvest energy from various sources, and some also use supercapacitors instead of batteries to address the battery aging problem. However, they either waste much available energy due to impedance mismatch, or they require active digital control that incurs

Pai H. Chou

2006-01-01

415

Domain engineered ferroelectric energy harvesters on a substrate  

NASA Astrophysics Data System (ADS)

Phase-field modeling is used to study the domain evolution of nano-scaled ferroelectric devices influenced by the mechanical strain of an underlying substrate. The investigations focus on the design of the energy harvesting systems to convert mechanical into electrical energy. Mechanical energy is provided by an alternating in-plane strain in the substrate through bending or unidirectional stretching. Additionally, lattice mismatch between the substrate and the ferroelectric material induces epitaxial strain and controls the polarization behavior within the system. Further, electrical boundary conditions are used to stabilize the domain topology. Finite element simulations are employed to explore the performance of the engineered domain topologies in delivering electrical charge from mechanical deformation.

Münch, I.; Krauß, M.; Landis, C. M.; Huber, J. E.

2011-05-01

416

Optically nonlinear energy transfer in light-harvesting dendrimers  

NASA Astrophysics Data System (ADS)

Dendrimeric polymers are the subject of intense research activity geared towards their implementation in nanodevice applications such as energy harvesting systems, organic light-emitting diodes, photosensitizers, low-threshold lasers, and quantum logic elements, etc. A recent development in this area has been the construction of dendrimers specifically designed to exhibit novel forms of optical nonlinearity, exploiting the unique properties of these materials at high levels of photon flux. Starting from a thorough treatment of the underlying theory based on the principles of molecular quantum electrodynamics, it is possible to identify and characterize several optically nonlinear mechanisms for directed energy transfer and energy pooling in multichromophore dendrimers. Such mechanisms fall into two classes: first, those where two-photon absorption by individual donors is followed by transfer of the net energy to an acceptor; second, those where the excitation of two electronically distinct but neighboring donor groups is followed by a collective migration of their energy to a suitable acceptor. Each transfer process is subject to minor dissipative losses. In this paper we describe in detail the balance of factors and the constraints that determines the favored mechanism, which include the excitation statistics, structure of the energy levels, laser coherence factors, chromophore selection rules and architecture, possibilities for the formation of delocalized excitons, spectral overlap, and the overall distribution of donors and acceptors. Furthermore, it transpires that quantum interference between different mechanisms can play an important role. Thus, as the relative importance of each mechanism determines the relevant nanophotonic characteristics, the results reported here afford the means for optimizing highly efficient light-harvesting dendrimer devices.

Andrews, David L.; Bradshaw, David S.

2004-08-01

417

Vibrations  

NASA Astrophysics Data System (ADS)

Low frequent vibrations may cause from disturbing up to damaging effects. There is no precise distinction between structure-borne sound and vibrations. However - depending on the frequency range - measurements and predictions require different techniques. In a wide frequency range, the generation, transmission and propagation of vibrations can be investigated similar to structure-borne sound (see Chap. 9).

Guggenberger, Johannes; Müller, Gerhard

418

Comparison of vibrational conductivity and radiative energy transfer methods  

Microsoft Academic Search

This paper is concerned with the comparison of two methods well suited for the prediction of the wideband response of built-up structures subjected to high-frequency vibrational excitation. The first method is sometimes called the vibrational conductivity method and the second one is rather known as the radiosity method in the field of acoustics, or the radiative energy transfer method. Both

A. Le Bot

2005-01-01

419

Modeling coherent excitation energy transfer in photosynthetic light harvesting systems  

NASA Astrophysics Data System (ADS)

Recent non-linear spectroscopy experiments suggest the excitation energy transfer in some biological light harvesting systems initially occurs coherently. Treating such processes brings significant challenge for conventional theoretical tools that usually involve different approximations. In this dissertation, the recently developed Iterative Linearized Density Matrix (ILDM) propagation scheme, which is non-perturbative and non-Markovian is extended to study coherent excitation energy transfer in various light harvesting complexes. It is demonstrated that the ILDM approach can successfully describe the coherent beating of the site populations on model systems and gives quantitative agreement with both experimental results and the results of other theoretical methods have been developed recently to going beyond the usual approximations, thus providing a new reliable theoretical tool to study this phenomenon. This approach is used to investigate the excited energy transfer dynamics in various experimentally studied bacteria light harvesting complexes, such as Fenna-Matthews-Olsen (FMO) complex, Phycocyanin 645 (PC645). In these model calculations, quantitative agreement is found between computed de-coherence times and quantum beating pattens observed in the non-linear spectroscopy. As a result of these studies, it is concluded that the stochastic resonance behavior is important in determining the optimal throughput. To begin addressing possible mechanics for observed long de-coherence time, various models which include correlation between site energy fluctuations as well as correlation between site energy and inter-site coupling are developed. The influence of both types of correlation on the coherence and transfer rate is explored using with a two state system-bath hamiltonian parametrized to model the reaction center of Rhodobacter sphaeroides bacteria. To overcome the disadvantages of a fully reduced approach or a full propagation method, a brownian dynamics method is developed that only treats those degrees of freedom which directly couple to quantum systems and hence maintain the non-Markovian nature of the dynamics in contrast to the fully reduced master equation. This brownian dynamics approach has a significant reduced computational cost compared with ILDM propagation. The algorithm is tested with a spin-boson-global bath model, and shows potential for capturing non-markovian features that will be lost with a fully reduced master equation description of the excitation energy transfer.

Huo, Pengfei

420

Multifunctional nanodevices for energy harvesting in unconventional spectral ranges  

NASA Astrophysics Data System (ADS)

New energy harvesting technologies have drawn interest in recent years for both military and commercial applications. We present complete analysis of a novel device technology based on nanowire antennas and very high speed rectifiers (collectively called nanorectenna) to convert infrared and THz electromagnetic radiation into DC power. A nanowire antenna can receive electromagnetic waves and an integrated rectifier can convert them into electrical energy. The induced voltage and current distributions of nanowire antennas for different geometric parameters at various frequencies are investigated and analyzed. Also, nanowire antenna arrays with different geometries and distributions are examined. Moreover, novel nanoantennas are proposed for broadband operation and power conversion. All numerical computations are conducted using Ansoft HFSS. An incident plane wave was used to excite each device and simulations were carried out for frequencies between 0 and 200 THz. A voltage is induced in each device and it is measured in the thin oxide layer. Finally, optimum geometries of nanowires are proposed in order to maximize the amount of infrared power that is harvested.

Imafidon, Osagie; Georgakopoulos, Stavros; Vabbina, Phani Kiran; Pala, Nezih

2010-04-01

421

Rapid energy transfer in a dendrimer having ?-conjugated light-harvesting antennas  

NASA Astrophysics Data System (ADS)

We investigate rapid energy transfer (ET) and its temperature dependence in a star-shaped stilbenoid phthalocyanine (SSS1Pc) dendrimer having ?-conjugated light-harvesting (LH) antennas, and develop an appropriate model. In SSS1Pc, an intense core photoluminescence (PL) band appears under the selective excitation of the absorption bands of the LH antenna due to highly efficient ET at room temperature (RT). The transient response of core-absorption bleaching and the temporal behaviours of the PL intensities of the core and antenna reveal that ET from the LH antenna occurs rapidly prior to achieving quasi-equilibrium in the photoexcited state of the LH antenna. In addition, it is also clarified that the ET quantum efficiency in SSS1Pc degrades at temperatures lower than ~100 K. To understand these results, we develop an ET model based on a ?-conjugating network between the LH antenna and the core that accounts for steric hindrance between the LH antenna and the torsional vibration of the LH-antenna subunit. This model reveals that highly efficient ET occurs at RT through the ?-conjugated network mediated by the thermally activated torsional vibration of the LH-antenna subunit.

Akai, I.; Miyanari, K.; Shimamoto, T.; Fujii, A.; Nakao, H.; Okada, A.; Kanemoto, K.; Karasawa, T.; Hashimoto, H.; Ishida, A.; Yamada, A.; Katayama, I.; Takeda, J.; Kimura, M.

2008-12-01

422

Energy Harvesting From Human and Machine Motion for Wireless Electronic Devices  

Microsoft Academic Search

Energy harvesting generators are attractive as inexhaustible replacements for batteries in low-power wireless electronic devices and have received increasing research interest in recent years. Ambient motion is one of the main sources of energy for harvesting, and a wide range of motion-powered energy harvesters have been proposed or demonstrated, particularly at the microscale. This paper reviews the principles and state-of-art

Paul D. Mitcheson; Eric M. Yeatman; G. Kondala Rao; Andrew S. Holmes; Tim C. Green

2008-01-01

423

Biomechanical energy harvesting from human motion: theory, state of the art, design guidelines, and future directions  

Microsoft Academic Search

Background  Biomechanical energy harvesting from human motion presents a promising clean alternative to electrical power supplied by batteries\\u000a for portable electronic devices and for computerized and motorized prosthetics. We present the theory of energy harvesting\\u000a from the human body and describe the amount of energy that can be harvested from body heat and from motions of various parts\\u000a of the body

Raziel Riemer; Amir Shapiro

2011-01-01

424

Comparisons of two methods of harvesting biomass for energy  

Microsoft Academic Search

Two harvesting methods for utilization of understory biomass were tested against a conventional harvesting method to determine relative costs. The conventional harvesting method tested removed all pine 6 inches diameter at breast height (DBH) and larger and hardwood sawlogs as tree length logs. The two intensive harvesting methods were a one-pass and a two-pass method. In the one-pass method, all

W. F. Watson; B. J. Stokes; I. W. Sabelle

1986-01-01

425

Improvement of Pyroelectric Cells for Thermal Energy Harvesting  

PubMed Central

This study proposes trenching piezoelectric (PZT) material in a thicker PZT pyroelectric cell to improve the temperature variation rate to enhance the efficiency of thermal energy-harvesting conversion by pyroelectricity. A thicker pyroelectric cell is beneficial in generating electricity pyroelectrically, but it hinders rapid temperature variations. Therefore, the PZT sheet was fabricated to produce deeper trenches to cause lateral temperature gradients induced by the trenched electrode, enhancing the temperature variation rate under homogeneous heat irradiation. When the trenched electrode type with an electrode width of 200 ?m and a cutting depth of 150 ?m was used to fabricate a PZT pyroelectric cell with a 200 ?m thick PZT sheet, the temperature variation rate was improved by about 55%. Therefore, the trenched electrode design did indeed enhance the temperature variation rate and the efficiency of pyroelectric energy converters.

Hsiao, Chun-Ching; Siao, An-Shen; Ciou, Jing-Chih

2012-01-01

426

Energy harvesting and wireless energy transmission for powering SHM sensor nodes  

SciTech Connect

In this paper, we present a feasibility study of using energy harvesting and wireless energy transmission systems to operate SHM sensor nodes. The energy harvesting approach examines the use of kinetic energy harvesters to scavenge energy from the ambient sources. Acceleration measurements were made on a bridge, and serve as the basis for a series of laboratory experiments that replicate these sources using an electromagnetic shaker. We also investigated the use of wireless energy transmission systems to operate SHM sensor nodes. The goal of this investigation is to develop SHM sensing systems which can be permanently embedded in the host structure and do not require on-board power sources. This paper summarizes considerations needed to design such systems, experimental procedures and results, and additional issues that can be used as guidelines for future investigations.

Taylor, Stuart G [Los Alamos National Laboratory; Farinholt, Kevin M [Los Alamos National Laboratory; Park, Gyuhae [Los Alamos National Laboratory; Farrar, Charles R [Los Alamos National Laboratory

2009-01-01

427

Nonlinear piezoelectricity in electroelastic energy harvesters: Modeling and experimental identification  

NASA Astrophysics Data System (ADS)

We propose and experimentally validate a first-principles based model for the nonlinear piezoelectric response of an electroelastic energy harvester. The analysis herein highlights the importance of modeling inherent piezoelectric nonlinearities that are not limited to higher order elastic effects but also include nonlinear coupling to a power harvesting circuit. Furthermore, a nonlinear damping mechanism is shown to accurately restrict the amplitude and bandwidth of the frequency response. The linear piezoelectric modeling framework widely accepted for theoretical investigations is demonstrated to be a weak presumption for near-resonant excitation amplitudes as low as 0.5 g in a prefabricated bimorph whose oscillation amplitudes remain geometrically linear for the full range of experimental tests performed (never exceeding 0.25% of the cantilever overhang length). Nonlinear coefficients are identified via a nonlinear least-squares optimization algorithm that utilizes an approximate analytic solution obtained by the method of harmonic balance. For lead zirconate titanate (PZT-5H), we obtained a fourth order elastic tensor component of c1111p=-3.6673×1017 N/m2 and a fourth order electroelastic tensor value of e3111=1.7212×108 m/V.

Stanton, Samuel C.; Erturk, Alper; Mann, Brian P.; Inman, Daniel J.

2010-10-01

428

Energy efficient transmission strategies for Body Sensor Networks with energy harvesting  

Microsoft Academic Search

This paper addresses the problem of develop- ing energy efficient transmission strategies for Body Sensor Networks (BSNs) with energy harvesting capabilities. It is assumed that two transmission modes that allow a tradeoff between the energy consumption and packet error probability are available to the sensors. Decision policies are developed to determine the transmission mode to use at a given instant

Alireza Seyedi; Biplab Sikdar

2008-01-01