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Last update: August 15, 2014.

1

Adaptive vibration energy harvesting

NASA Astrophysics Data System (ADS)

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 such as wind, seismic forces and traffic. Existing approaches to vibration energy harvesting typically utilise a rectifier circuit, which is tuned to the resonant frequency of the harvesting structure and the dominant frequency of vibration. We have developed a novel approach to vibration energy harvesting, including adaption to non-periodic vibrations so as to extract the maximum amount of vibration energy available. Experimental results of an experimental apparatus using off-the-shelf transducer (i.e. speaker coil) show mechanical vibration to electrical energy conversion efficiencies of 27 - 34%. However, simulations of a more electro-mechanical efficient and lightly damped transducer show conversion efficiencies in excess of 80%.

Behrens, Sam; Ward, John; Davidson, Josh

2007-03-01

2

A broadband vibrational energy harvester

NASA Astrophysics Data System (ADS)

We propose a design for an energy harvester which has the potential to harvest vibrational energy over a broad range of ambient frequencies. The device uses two flexible ceramic piezoelectric elements arranged in a buckled configuration in the absence of vibrations. Experimental data show that this design allows enhanced harvesting of energy relative to a comparable cantilever design, both for periodic and stochastic vibrations. Moreover, the data suggest that this harvester has its peak energy generation when it responds with chaotic vibrations.

Van Blarigan, Louis; Danzl, Per; Moehlis, Jeff

2012-06-01

3

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

4

Nonlinear vibration energy harvester using diamagnetic levitation

This letter proposes a nonlinear vibration energy harvester based on stabilized magnetic levitation using diamagnetic. Restoring forces induced by the magnetic field in harvesting vibration energy is employed instead of the forces introduced by conventional mechanical suspensions; therefore dissipation of vibration energy into heat through mechanical suspensions is eliminated. The core of the design consists of two spiral coils made

L. Liu; F. G. Yuan

2011-01-01

5

Adaptive learning algorithms for vibration energy harvesting

NASA Astrophysics Data System (ADS)

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 range of sources such as human movement, wind, seismic forces and traffic. Existing approaches to vibration energy harvesting typically utilize a rectifier circuit, which is tuned to the resonant frequency of the harvesting structure and the dominant frequency of vibration. We have developed a novel approach to vibration energy harvesting, including adaptation to non-periodic vibrations so as to extract the maximum amount of vibration energy available. Experimental results of an experimental apparatus using an off-the-shelf transducer (i.e. speaker coil) show mechanical vibration to electrical energy conversion efficiencies of 27-34%.

Ward, John K.; Behrens, Sam

2008-06-01

6

Energy Harvesters Driven by Broadband Random Vibrations

Simple analytical models have proved very useful in understanding vibration energy harvesters driven by a sinusoidal acceleration. Corresponding analyses for broadband excitations have been absent. In this paper, we present new closed-form results on the output power, proof mass displacement, and optimal load of linear resonant energy harvesters driven by broadband vibrations. Output power dependence on signal bandwidth is also

Einar Halvorsen

2008-01-01

7

Vibration energy harvester optimization using artificial intelligence

NASA Astrophysics Data System (ADS)

This paper deals with an optimization study of a vibration energy harvester. This harvester can be used as autonomous source of electrical energy for remote or wireless applications, which are placed in environment excited by ambient mechanical vibrations. The ambient energy of vibrations is usually on very low level but the harvester can be used as alternative source of energy for electronic devices with an expected low level of power consumption of several mW. The optimized design of the vibration energy harvester was based on previous development and the sensitivity of harvester design was improved for effective harvesting from mechanical vibrations in aeronautic applications. The vibration energy harvester is a mechatronic system which generates electrical energy from ambient vibrations due to precision tuning up generator parameters. The optimization study for maximization of harvested power or minimization of volume and weight are the main goals of our development. The optimization study of such complex device is complicated therefore artificial intelligence methods can be used for tuning up optimal harvester parameters.

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

2011-05-01

8

Scaling of electromagnetic vibration energy harvesting devices

NASA Astrophysics Data System (ADS)

A review of the vibration energy harvesting literature has been undertaken with the goal of establishing scaling laws for experimentally demonstrated harvesting devices. In particular electromagnetic harvesting devices are investigated. Power density metrics are examined with respect to scaling length, mass, frequency and drive acceleration. Improvements in demonstrated power density of harvesting devices over the past decade are noted. Scaling laws are observed that appear to suggest an upper limit to the power density achievable with current harvesting techniques.

Moss, Scott D.; Payne, Owen R.; Hart, Genevieve A.

2014-04-01

9

Nonlinear vibration energy harvester using diamagnetic levitation

NASA Astrophysics Data System (ADS)

This letter proposes a nonlinear vibration energy harvester based on stabilized magnetic levitation using diamagnetic. Restoring forces induced by the magnetic field in harvesting vibration energy is employed instead of the forces introduced by conventional mechanical suspensions; therefore dissipation of vibration energy into heat through mechanical suspensions is eliminated. The core of the design consists of two spiral coils made of diamagnetic materials, which serve dual purposes: providing nonlinear restoring force and harnessing eddy current to power external circuits. From the theoretical analysis presented, the proposed harvester has the potential to provide wideband power outputs in low frequency range.

Liu, L.; Yuan, F. G.

2011-05-01

10

Vibration energy harvesting by magnetostrictive material

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

11

A vibration energy harvesting device with bidirectional resonance frequency tunability

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

12

On energy harvesting from ambient vibration

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

13

Vibration energy harvesting by magnetostrictive material

NASA Astrophysics Data System (ADS)

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 vibrations. To enhance the energy conversion efficiency and alleviate the need of a bias magnetic field, Metglas ribbons are transversely annealed by a strong magnetic field along their width direction. To analyze the MsM harvesting device a generalized electromechanical circuit model is derived from Hamilton's principle in conjunction with the normal mode superposition method based on Euler-Bernoulli beam theory. The MsM harvesting device is equivalent to an electromechanical gyrator in series with an inductor. In addition, the proposed model can be readily extended to a more practical case of a cantilever beam element with a tip mass. The energy harvesting circuit, which interfaces with a wireless sensor and accumulates the harvested energy into an ultracapacitor, is designed on a printed circuit board (PCB) with plane dimension 25 mm × 35 mm. It mainly consists of a voltage quadrupler, a 3 F ultracapacitor and a smart regulator. The output DC voltage from the PCB can be adjusted within 2.0-5.5 V. In experiments, the maximum output power and power density on the resistor can reach 200 µW and 900 µW cm-3, respectively, at a low frequency of 58 Hz. For a working prototype under a vibration with resonance frequency of 1.1 kHz and peak acceleration of 8.06 m s-2 (0.82 g), the average power and power density during charging the ultracapacitor can achieve 576 µW and 606 µW cm-3, respectively, which compete favorably with piezoelectric vibration energy harvesters.

Wang, Lei; Yuan, F. G.

2008-08-01

14

A magnetically levitated vibration energy harvester

NASA Astrophysics Data System (ADS)

In this paper a novel electromagnetic vibration type energy harvester that uses a diamagnetic levitation system is conceptualized, designed, fabricated, and tested. The harvester uses two diamagnetic plates made of pyrolytic graphite between which a cylindrical magnet levitates passively. Two thick cylindrical coils, placed in grooves which are engraved in the pyrolytic graphite plates, are used to convert the mechanical energy into electrical energy efficiently. The geometric configurations of the coils are selected based on the field distribution of the magnet to enhance the efficiency of the harvester. A thorough theoretical analysis is carried out to compare with experimental results. At an input power of 103.45 ?W and at a frequency of 2.7 Hz, the harvester generated a power of 0.74 ?W with a system efficiency of 0.72%. Both theoretical and experimental results show that this new energy harvesting system can capture low frequency broadband spectra.

Wang, X. Y.; Palagummi, S.; Liu, L.; Yuan, F. G.

2013-05-01

15

A vibration energy harvester using diamagnetic levitation

NASA Astrophysics Data System (ADS)

In this paper a novel electromagnetic vibration type energy harvester which uses a diamagnetic levitation system is conceptualized, designed, fabricated, and tested. The harvester uses two diamagnetic plates made of pyrolytic graphite between which a cylindrical magnet levitates passively. Two archimedean spiral coils are placed in grooves which are engraved in the pyrolytic graphite plates, used to convert the mechanical energy into electrical energy efficiently. The geometric configurations of coils are selected based on the field distribution of the magnet to enhance the efficiency of the harvester. A thorough theoretical analysis is done to compare with the experiment results. At an input power of 103.45 ?W and at a frequency of 2.7 Hz, the harvester generated a power of 0.744 ?W at an efficiency of 0.72 %. Both theoretical and experimental results show that this new energy harvesting system is efficient and can capture low frequency broadband spectra.

Palagummi, S.; Yuan, F. G.

2013-04-01

16

Vibration based energy harvesting using piezoelectric material

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

17

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

18

A wideband vibration-based energy harvester

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

19

A retrofitted energy harvester for low frequency vibrations

Piezoelectric-based energy harvesting is an efficient way to convert ambient vibration energy into usable electric energy. However, its output power drops steeply with reducing excitation frequency. To improve the harvesting performance at low frequencies, a multi-impact harvester is proposed in this paper. The proposed design consists of a hung mass and two stiff piezoelectric cantilever beams. A series of impacts

Ye Zhang; C S Cai

2012-01-01

20

A wideband vibration-based energy harvester

NASA Astrophysics Data System (ADS)

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 the same bandwidth in a down-sweep. Closed-form expressions for the response of the new MPG as well as the up-sweep bandwidth are presented and validated experimentally. Simulations show that under random-frequency excitations, the new MPG collects more energy than the traditional MPG.

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

2008-11-01

21

On the Effectiveness of Vibration-based Energy Harvesting

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

22

Vibration energy harvesting from random force and motion excitations

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

23

Feasibility study of multi-directional vibration energy harvesting with a frame harvester

NASA Astrophysics Data System (ADS)

Vibration energy harvesting using piezoelectric material is a promising solution for powering small electric devices, which has attracted great research interest in recent years. Numerous efforts have been done by researchers to improve the efficiency of vibration energy harvesters and to broaden their bandwidths. In most reported literature, harvesters are designed to harvest energy from vibration source with a specific excitation direction. However, a practical environmental vibration source may include multiple components from different directions. Thus, it is an important concern to design a vibration energy harvester to be adaptive to multiple excitation directions. In this article, a novel piezoelectric energy harvester with frame configuration is proposed to address this issue. It can work either in its vertical vibration mode or horizontal vibration mode. Therefore, the harvester can capture vibration energy from arbitrary directions in a twodimensional plane. Experimental studies are carried out to prove the feasibility for multiple-direction energy harvesting using such harvester. The development of this two-dimensional energy harvester indicates its promising potential in practical vibration scenarios.

Wu, Hao; Tang, Lihua; Yang, Yaowen; Soh, Chee Kiong

2014-03-01

24

On Mechanical Modeling of Cantilevered Piezoelectric Vibration Energy Harvesters

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

25

Magnetoelectric Energy Harvesting from Vibrations of Multiple Frequencies

A novel multi-frequency vibration energy harvester has been designed and fabricated, which consists of two cantilever beams, two magnetoelectric (ME) transducers and a magnetic circuit. In the harvester, the magnetic forces between the ME transducers and the magnetic circuit will result in additional magnetic stiffness on the two cantilever beams, on which the frequency response of the harvester is highly

Jin Yang; Yumei Wen; Ping Li

2011-01-01

26

A vibration energy harvester using magnet/piezoelectric composite transducer

NASA Astrophysics Data System (ADS)

In this research, a vibration energy harvester employing the magnet/piezoelectric composite transducer to convert mechanical vibration energy into electrical energy is presented. The electric output performance of a vibration energy harvester has been investigated. Compared to traditional magnetoelectric transducer, the proposed vibration energy harvester has some remarkable characteristic which do not need binder. The experimental results show that the presented vibration energy harvester can obtain an average power of 0.39 mW for an acceleration of 0.6g at frequency of 38 Hz. Remarkably, this power is a very encouraging power figure that gives the prospect of being able to power a widely range of wireless sensors in wireless sensor network.

Qiu, Jing; Chen, Hengjia; Wen, Yumei; Li, Ping; Yang, Jin; Li, Wenli

2014-05-01

27

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

28

A variable-capacitance vibration-to-electric energy harvester

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

29

The bandwidth of optimized nonlinear vibration-based energy harvesters

NASA Astrophysics Data System (ADS)

In an attempt to improve the performance of vibration-based energy harvesters, many authors suggest that nonlinearities can be exploited to increase the bandwidths of linear devices. Nevertheless, the complex dependence of the response upon the input excitation has made a realistic comparison of linear harvesters with nonlinear energy harvesters challenging. In a previous work it has been demonstrated that for a given frequency of excitation, it is possible to achieve the same maximum power for a nonlinear harvester as that for a linear harvester, provided that the resistance and the linear stiffness of both are optimized. This work focuses on the bandwidths of linear and nonlinear harvesters and shows which device is more suitable for harvesting energy from vibrations. The work considers different levels of excitation as well as different frequencies of excitation. In addition, the effect of the mechanical damping of the oscillator on the power bandwidth is shown for both the linear and nonlinear cases.

Cammarano, A.; Neild, S. A.; Burrow, S. G.; Inman, D. J.

2014-05-01

30

MEMS-based thick film PZT vibrational energy harvester

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

31

Power-amplifying strategy in vibration-powered energy harvesters

A new cantilevered piezoelectric energy harvester (PEH) of which the additional lumped mass is connected to a harmonically oscillating base through an elastic foundation is proposed for maximizing generated power and enlarging its frequency bandwidth. The base motion is assumed to provide a given acceleration level. Earlier, a similar energy harvester employing the concept of the dynamic vibration absorber was

Pyung Sik Ma; Jae Eun Kim; Yoon Young Kim

2010-01-01

32

Wideband vibration energy harvester with high permeability magnetic material

A vibration energy harvester based on a high permeability cantilever beam was demonstrated, which overcomes the limitation of the existing approaches in output power and working bandwidth. Magnetostatic coupling between the vibrating highly permeable beam and bias magnetic field leads to maximized flux change and large induced voltage. The coexistence of magnetostatic and elastic potential energy results in the nonlinear

X. Xing; J. Lou; G. M. Yang; O. Obi; C. Driscoll; N. X. Sun

2009-01-01

33

Vibration energy harvesting using a spherical permanent magnet

NASA Astrophysics Data System (ADS)

The authors recently reported on a hybrid rotary-translational vibration energy harvesting approach using a spherical permanent-magnet and employing cycloidal motion as a mechanical amplifier. The rotary-translational harvesting approach, which is resonant in nature, can yield approximately twice the e.m.f. compared with a similar translationalonly device. This paper explores the analytic and numerical modelling of the rotary-translational harvester with the goal of finding an efficient method for design optimisation.

Moss, Scott D.; Hart, Genevieve A.; Burke, Stephen K.; Galea, Steve C.; Carman, Gregory P.

2014-04-01

34

A low frequency vibration energy harvester using magnetoelectric laminate composite

NASA Astrophysics Data System (ADS)

In this paper, we present a vibration energy harvester using magnetoelectric laminate composite and a springless spherical permanent magnet as a proof mass. The harvester utilizes a freely movable spherical permanent magnet to transform external vibration into a time varying magnetic field applied to the magnetoelectric transducer. The laminate composite consists of a Ni-Mn-Ga-based MSMA (magnetic shape memory alloy) element and a PZT (lead zirconate titanate) plate. A proof-of-concept harvester has been fabricated and characterized at various input accelerations and frequencies. A maximum open circuit voltage of 1.18 V has been obtained in response to a 3g vibration at 17 Hz with the fabricated device. Moreover, a maximum output voltage of 10.24 V and output power of 4.1 ?W have been achieved on a 950 ? load, when the fabricated energy harvester was mounted on a smartphone and shaken by hand.

Ju, Suna; Chae, Song Hee; Choi, Yunhee; Lee, Seungjun; Lee, Hyang Woon; Ji, Chang-Hyeon

2013-11-01

35

A Vibration-Based PMN-PT Energy Harvester

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

36

Development of a Cantilever Beam Generator Employing Vibration Energy Harvesting

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

37

Improved Energy Harvesting from Wideband Vibrations by Nonlinear Piezoelectric Converters

Vibration harvesters typically are linear mass-spring devices working at resonance. A different approach is here proposed based on nonlinear converters that exploit stochastic resonance with white-noise excitation. A piezoelectric beam converter is coupled to permanent magnets creating a bistable system bouncing between two stable states in response to random excitation. Under proper conditions, this significantly improves energy harvesting from wide-spectrum

Marco Ferrari; Vittorio Ferrari; Michele Guizzetti; Bruno Andò; Salvatore Baglio; Carlo Trigona

2009-01-01

38

Power-amplifying strategy in vibration-powered energy harvesters

NASA Astrophysics Data System (ADS)

A new cantilevered piezoelectric energy harvester (PEH) of which the additional lumped mass is connected to a harmonically oscillating base through an elastic foundation is proposed for maximizing generated power and enlarging its frequency bandwidth. The base motion is assumed to provide a given acceleration level. Earlier, a similar energy harvester employing the concept of the dynamic vibration absorber was developed but the mechanism of the present energy harvester is new because it incorporates a mass-spring system in addition to a conventional cantilevered piezoelectric energy harvesting beam with or without a tip mass. Consequently, the proposed energy harvester actually forms a two-degree-of-freedom system. It will be theoretically shown that the output power can be indeed substantially improved if the fundamental resonant frequencies of each of the two systems in the proposed energy harvester are simultaneously tuned as closely as possible to the input excitation frequency and also if the mass ratio of a piezoelectric energy harvesting beam to the lumped mass is adjusted below a certain value. The performance of the proposed energy harvester is checked by numerical simulation.

Ma, Pyung Sik; Kim, Jae Eun; Kim, Yoon Young

2010-03-01

39

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

40

A micro electromagnetic generator for vibration energy harvesting

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

41

Fundamental issues in nonlinear wideband-vibration energy harvesting

NASA Astrophysics Data System (ADS)

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.

Halvorsen, Einar

2013-04-01

42

Fundamental issues in nonlinear wideband-vibration energy harvesting.

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

2013-04-01

43

A vibration energy harvesting sensor platform for increased industrial efficiency

A model for piezoelectric vibration energy harvesting with a piezoelectric cantilever beam is presented. The model incorporates expressions for variable geometry, tip mass, and material constants, and allows the parameterized determination of the voltage and power produced over a purely resistive load. The model is of a lumped-element form, with the base excitation acceleration and voltage representing the effort variables,

Todd A. Anderson; Daniel W. Sexton

2006-01-01

44

A Vibration Energy Harvesting Sensor Platform for Increased Industrial Efficiency

A model for piezoelectric vibration energy harvesting with a piezoelectric cantilever beam is presented. The model incorporates expressions for variable geometry, tip mass, and material constants, and allows the parameterized determination of the voltage and power produced over a purely resistive load. The model is of a lumped-element form, with the base excitation acceleration and voltage representing the effort variables,

Todd A. Anderson; Daniel W. Sexton

2006-01-01

45

Modelling of a Bi-axial Vibration Energy Harvester.

National Technical Information Service (NTIS)

This report fully details the techniques involved in the modelling of a nonlinear and bi-axial vibration energy harvesting device. The device utilises a wire-coil electromagnetic (EM) transducer within a nonlinear oscillator created with a permanent-magne...

L. A. Vandewater S. D. Moss

2013-01-01

46

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

47

Tapered piezoelectric devices for vibration energy harvesting

NASA Astrophysics Data System (ADS)

The use of cantilevered piezoelectric bimorphs under transversal excitations is an area of research well reported in literature. These devices may be tapered into triangular geometries in order to enhance axial strain over the surfaces of the device for more reliable operation. This study reports the comparison of rectangular and triangular cantilevered bimorphs of equal volume and matching resonance frequency, where it is seen that tapering geometry enhances the electromechanical coupling coefficient, which may not necessarily be the only parameter involved in enhancing power output. This is indicated in the case of a triangular cantilevered device without a proof mass, which with increased coupling is unable to outperform a rectangular device. The addition of a nominal proof mass on a rectangular and triangular device increases not only the electromechanical coupling coefficient, but also increases the damping ratio in the devices. This effect is more pronounced in the case of triangular bimorphs, and a 40% improvement in power output is seen. Therefore, these studies provides insights into the changing parameters with changing shapes, which may provide better optimization parameters for improving piezoelectric energy harvesting from cantilevered devices.

Siddiqui, Naved A.; Roberts, Matthew I.; Kim, Dong-Joo; Overfelt, Ruel A.; Prorok, Barton C.

2014-03-01

48

MEMS-Based Waste Vibrational Energy Harvesters.

National Technical Information Service (NTIS)

The piezoelectric effect is a phenomenon where strain on a piezoelectric crystal structure causes potential difference at its ends. By merging piezoelectric materials and microelectromechanical systems (MEMS), mechanical vibration could cause the necessar...

D. B. Hogue S. M. Gregory

2013-01-01

49

Energy harvester array using piezoelectric circular diaphragm for broadband vibration

NASA Astrophysics Data System (ADS)

A piezoelectric generator fabricated by multiple circular diaphragm piezoelectric harvesters array is provided to harvest power over a broad range of frequencies. Four harvesters with varies tip masses are incorporated on a board with an area of 98 × 98 mm2. In this case, four strong output power peaks are obtained over frequencies from 120 Hz to 225 Hz. With an optimum load resistance of 15 k?, the value of four output power peaks is, respectively, 5.14, 6.65, 9.7, and 10 mW for the generator under an acceleration of 9.8 m/s2. By choosing an appropriate combination of tip masses with piezoelectric elements in array, the frequency range of energy harvesting can be obviously widened to meet the broadband vibration.

Xiao, Zhao; Yang, Tong qing; Dong, Ying; Wang, Xiu cai

2014-06-01

50

Piezoelectric buckled beams for random vibration energy harvesting

Among the main vibration-to-electricity conversion systems, resonant harvesters suffer from a series of strong limits like their narrow frequency response and poor output power at small scale. Most of all, realistic vibration sources are variable in time and abundant at relatively low frequencies. Nonlinear vibration harvesters, on the other hand, are more attractive, thanks to their large bandwidth response and

F Cottone; L Gammaitoni; H Vocca; M Ferrari; V Ferrari

2012-01-01

51

Wideband vibration energy harvester with high permeability magnetic material

NASA Astrophysics Data System (ADS)

A vibration energy harvester based on a high permeability cantilever beam was demonstrated, which overcomes the limitation of the existing approaches in output power and working bandwidth. Magnetostatic coupling between the vibrating highly permeable beam and bias magnetic field leads to maximized flux change and large induced voltage. The coexistence of magnetostatic and elastic potential energy results in the nonlinear oscillation with wide bandwidth. The harvester showed a maximum power of 74 mW and power density of 1.07 mW/cm3 at 54 Hz under acceleration of 0.57 g (with g=9.8 m/s2), and bandwidth of 10 Hz (or 18.5% of the operating frequency).

Xing, X.; Lou, J.; Yang, G. M.; Obi, O.; Driscoll, C.; Sun, N. X.

2009-09-01

52

Piezoelectric buckled beams for random vibration energy harvesting

NASA Astrophysics Data System (ADS)

Among the main vibration-to-electricity conversion systems, resonant harvesters suffer from a series of strong limits like their narrow frequency response and poor output power at small scale. Most of all, realistic vibration sources are variable in time and abundant at relatively low frequencies. Nonlinear vibration harvesters, on the other hand, are more attractive, thanks to their large bandwidth response and flexibility to convert kinetic energy of the natural frequency of the sources. In particular, bistable oscillators have been proven to show higher global performances when excited by random vibrations. In this paper, such an approach is investigated for piezoelectric beams by exerting an increasing axial compression. An advantage of this technique is the absence of magnetic forces to create bistable dynamics. A thin piezoelectric axially loaded beam is theoretically modelled and experimentally investigated under wideband random vibrations. In the buckled configuration, the device exhibits superior power generation over a large interval of resistive load, with gains up to more than a factor of ten compared to the unbuckled state. The numerical model and experimental results are in good qualitative agreement.

Cottone, F.; Gammaitoni, L.; Vocca, H.; Ferrari, M.; Ferrari, V.

2012-03-01

53

Enhanced vibration based energy harvesting using embedded acoustic black holes

NASA Astrophysics Data System (ADS)

In this paper, we investigate the use of dynamic structural tailoring via the concept of an Acoustic Black Hole (ABH) to enhance the performance of piezoelectric based energy harvesting from operational mechanical vibrations. The ABH is a variable thickness structural feature that can be embedded in the host structure allowing a smooth reduction of the phase velocity while minimizing the amplitude of reflected waves. The ABH thickness variation is typically designed according to power-law profiles. As a propagating wave enters the ABH, it is progressively slowed down while its wavelength is compressed. This effect results in structural areas with high energy density that can be exploited effectively for energy harvesting. The potential of ABH for energy harvesting is shown via a numerical study based on fully coupled finite element electromechanical models of an ABH tapered plate with surface mounted piezo-transducers. The performances of the novel design are evaluated by direct comparison with a non-tapered structure in terms of energy ratios and attenuation indices. Results show that the tailored structural design allows a drastic increase in the harvested energy both for steady state and transient excitation. Performance dependencies of key design parameters are also investigated.

Zhao, L.; Semperlotti, F.; Conlon, S. C.

2014-03-01

54

Multistable chain for ocean wave vibration energy harvesting

NASA Astrophysics Data System (ADS)

The heaving of ocean waves is a largely untapped, renewable kinetic energy resource. Conversion of this energy into electrical power could integrate with solar technologies to provide for round-the-clock, portable, and mobile energy supplies usable in a wide variety of marine environments. However, the direct drive conversion methodology of gridintegrated wave energy converters does not efficiently scale down to smaller, portable architectures. This research develops an alternative power conversion approach to harness the extraordinarily large heaving displacements and long oscillation periods as an excitation source for an extendible vibration energy harvesting chain. Building upon related research findings and engineering insights, the proposed system joins together a series of dynamic cells through bistable interfaces. Individual impulse events are generated as the inertial mass of each cell is pulled across a region of negative stiffness to induce local snap through dynamics; the oscillating magnetic inertial mass then generates current in a coil which is connected to energy harvesting circuitry. It is shown that linking the cells into a chain transmits impulses through the system leading to cascades of vibration and enhancement of electrical energy conversion from each impulse event. This paper describes the development of the multistable chain and ways in which realistic design challenges were addressed. Numerical modeling and corresponding experiments demonstrate the response of the chain due to slow and large amplitude input motion. Lastly, experimental studies give evidence that energy conversion efficiency of the chain for wave energy conversion is much higher than using an equal number of cells without connections.

Harne, R. L.; Schoemaker, M. E.; Wang, K. W.

2014-03-01

55

A New Wideband Electromagnetic Vibration Energy Harvester with Chaotic Oscillation

NASA Astrophysics Data System (ADS)

This paper presents a new electromagnetic vibration energy harvester (VEH) which harvests the electric power in wide frequency range. The present VEH contains the ferrite core embedded in the axis hole of the coil bobbin which generates the magnetic force acting on the oscillator. The performance of the present VEH is estimated using the coupled analysis method for VEH in which motion, Ampere, and circuit equations are alternatively solved until convergence. Using the coupled analysis method, the output power characteristic in the present VEH against input frequency is analyzed. It is shown from the analysis results that the present VEH has chaotic oscillation and wide frequency range for power generation. Moreover, the condition that the present VEH has nonlinear oscillation is discussed.

Sato, Takahiro; Igarashi, Hajime

2013-12-01

56

Efficiency Enhancement of a Cantilever-Based Vibration Energy Harvester

Extracting energy from ambient vibration to power wireless sensor nodes has been an attractive area of research, particularly in the automotive monitoring field. This article reports the design, analysis and testing of a vibration energy harvesting device based on a miniature asymmetric air-spaced cantilever. The developed design offers high power density, and delivers electric power that is sufficient to support most wireless sensor nodes for structural health monitoring (SHM) applications. The optimized design underwent three evolutionary steps, starting from a simple cantilever design, going through an air-spaced cantilever, and ending up with an optimized air-spaced geometry with boosted power density level. Finite Element Analysis (FEA) was used as an initial tool to compare the three geometries' stiffness (K), output open-circuit voltage (Vave), and average normal strain in the piezoelectric transducer (?ave) that directly affect its output voltage. Experimental tests were also carried out in order to examine the energy harvesting level in each of the three designs. The experimental results show how to boost the power output level in a thin air-spaced cantilever beam for energy within the same space envelope. The developed thin air-spaced cantilever (8.37 cm3), has a maximum power output of 2.05 mW (H = 29.29 ?J/cycle).

Kubba, Ali E.; Jiang, Kyle

2014-01-01

57

A vibration energy harvesting sensor platform for increased industrial efficiency

NASA Astrophysics Data System (ADS)

A model for piezoelectric vibration energy harvesting with a piezoelectric cantilever beam is presented. The model incorporates expressions for variable geometry, tip mass, and material constants, and allows the parameterized determination of the voltage and power produced over a purely resistive load. The model is of a lumped-element form, with the base excitation acceleration and voltage representing the effort variables, and the tip velocity and electrical current representing the flow variables. Subsequent to the model's derivation, experimental results are presented and demonstrate the accuracy of the model. As peak power output for existing vibration configurations is typically of interest, several simple optimization studies are then performed on a simple generator configuration to demonstrate the effects of several of the driving geometric and material parameters.

Anderson, Todd A.; Sexton, Daniel W.

2006-04-01

58

Harvesting energy from the natural vibration of human walking.

The triboelectric nanogenerator (TENG), a unique technology for harvesting ambient mechanical energy based on the triboelectric effect, has been proven to be a cost-effective, simple, and robust approach for self-powered systems. However, a general challenge is that the output current is usually low. Here, we demonstrated a rationally designed TENG with integrated rhombic gridding, which greatly improved the total current output owing to the structurally multiplied unit cells connected in parallel. With the hybridization of both the contact-separation mode and sliding electrification mode among nanowire arrays and nanopores fabricated onto the surfaces of two contact plates, the newly designed TENG produces an open-circuit voltage up to 428 V, and a short-circuit current of 1.395 mA with the peak power density of 30.7 W/m(2). Relying on the TENG, a self-powered backpack was developed with a vibration-to-electric energy conversion efficiency up to 10.62(±1.19) %. And it was also demonstrated as a direct power source for instantaneously lighting 40 commercial light-emitting diodes by harvesting the vibration energy from natural human walking. The newly designed TENG can be a mobile power source for field engineers, explorers, and disaster-relief workers. PMID:24180642

Yang, Weiqing; Chen, Jun; Zhu, Guang; Yang, Jin; Bai, Peng; Su, Yuanjie; Jing, Qingsheng; Cao, Xia; Wang, Zhong Lin

2013-12-23

59

Vibration energy harvesting using a piezoelectric circular diaphragm array.

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

60

NASA Astrophysics Data System (ADS)

The design of vibration energy harvesters (VEHs) is highly dependent upon the characteristics of the environmental vibrations present in the intended application. VEHs can be linear resonant systems tuned to particular frequencies or nonlinear systems with either bistable operation or a Duffing-type response. This paper provides detailed vibration data from a range of applications, which has been made freely available for download through the Energy Harvesting Network’s online data repository. In particular, this research shows that simulation is essential in designing and selecting the most suitable vibration energy harvester for particular applications. This is illustrated through C-based simulations of different types of VEHs, using real vibration data from a diesel ferry engine, a combined heat and power pump, a petrol car engine and a helicopter. The analysis shows that a bistable energy harvester only has a higher output power than a linear or Duffing-type nonlinear energy harvester with the same Q-factor when it is subjected to white noise vibration. The analysis also indicates that piezoelectric transduction mechanisms are more suitable for bistable energy harvesters than electromagnetic transduction. Furthermore, the linear energy harvester has a higher output power compared to the Duffing-type nonlinear energy harvester with the same Q factor in most cases. The Duffing-type nonlinear energy harvester can generate more power than the linear energy harvester only when it is excited at vibrations with multiple peaks and the frequencies of these peaks are within its bandwidth. Through these new observations, this paper illustrates the importance of simulation in the design of energy harvesting systems, with particular emphasis on the need to incorporate real vibration data.

Beeby, Stephen P.; Wang, Leran; Zhu, Dibin; Weddell, Alex S.; Merrett, Geoff V.; Stark, Bernard; Szarka, Gyorgy; Al-Hashimi, Bashir M.

2013-07-01

61

Improved energy harvesting from wideband vibrations by nonlinear piezoelectric converters

Vibration harvesters typically are linear mass-spring devices working at resonance. A different approach is here proposed based on nonlinear converters that exploit stochastic resonance with white-noise excitation. It consists of a piezoelectric beam converter coupled to permanent magnets to create a bistable system. Under proper conditions, the system bounces between two stable states in response to random excitation, which significantly

M. Ferrari; V. Ferrari; M. Guizzetti; B. Andò; S. Baglio; C. Trigona

2010-01-01

62

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

63

An energy-adaptive MPPT power management unit for micro-power vibration energy harvesting

A batteryless power management unit (PMU) that manages harvested low-level vibration energy from a piezoelectric device for a wireless sensor node is presented. An energy-adaptive maximum power point tracking (EA-MPPT) scheme is proposed that allows the PMU to activate different operation modes according to the available power level. The harvested energy is processed by an ac-dc voltage doubler followed by

Jun Yi; Feng Su; Yat-hei Lam; Wing-hung Ki; Chi-ying Tsui

2008-01-01

64

Vibration energy harvesting using a phononic crystal with point defect states

NASA Astrophysics Data System (ADS)

A vibration energy harvesting generator was studied in the present research using point-defect phononic crystal with piezoelectric material. By removing a rod from a perfect phononic crystal, a resonant cavity was formed. The elastic waves in the range of gap frequencies were all forbidden in any direction, while the waves with resonant frequency were localized and enhanced in the resonant cavity. The collected vibration energy was converted into electric energy by putting a polyvinylidene fluoride film in the middle of the defect. This structure can be used to simultaneously realize both vibration damping and broad-distributed vibration energy harvesting.

Lv, Hangyuan; Tian, Xiaoyong; Wang, Michael Yu; Li, Dichen

2013-01-01

65

Electromagnetic energy harvesting from vibrations of multiple frequencies

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

66

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

67

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

Miller, Lindsay Margaret

68

Piezoelectric energy harvesting devices for low frequency vibration applications

NASA Astrophysics Data System (ADS)

Energy harvesting, a process of capturing ambient waste energy and converting it into usable electricity, has been attracting more and more researchers' interest because of the limitations of traditional power sources, the increasing demands upon mobile devices such as wireless sensor networks, and the recent advent of the extremely low power electrical and mechanical devices such as microelectromechanical systems (MEMS). In this research, bulk- and wafer-scale of piezoelectric power generator prototypes were developed. The Lead Zirconate Titanate (PZT) bimorph cantilever in bulk scale with a big proof mass at the free end tip was studied to convert ambient vibration energy of 100 Hz and above 1g (1g = 9.81 m/s2) acceleration amplitudes. The optimal design was based on matching the resonant frequency of the device with the environmental exciting frequency, and balancing the power output and the fracture safety factor. The fabricated PZT power generator with an effective volume of 0.0564 cm3 and a safety factor of 10g can produce 6.21 Vpk, 257 microW, or 4558 microW/cm 3 with an optimal resistive load of 75 kO from 1g acceleration at its resonant frequency of 97.6 Hz. To overcome the high fragility of PZT, substitute piezoelectric materials, Macro Fiber Composite (MFC) and polyvinylidene fluoride (PVDF), and alternative operational ambient for power generators were investigated for high vibration amplitude applications. Before fabricating piezoelectric power generators in wafer scale, interlayer effects on the properties of PZT thin film were surveyed. The fabricated device based on Si wafer, with a beam dimension about 4.800 mm x 0.400 mm x 0.036 mm and an integrated Si mass dimension about 1.360 mm x 0.940 mm x 0.456 mm produced 160 mVpk, 2.13 microW, or 3272 microW/cm3 with the optimal resistive load of 6 kO from 2g acceleration at its resonant frequency of 461.15 Hz. To precisely control the resonant frequency of the power generator, Si on insulator (SOI) wafer substitutes for Si wafer. The resonant frequency of the fabricated device is as low as about 184 Hz. The difference between the calculated and measured resonant frequency has been decreased to 4.25%.

Shen, Dongna

69

DESIGN CONSIDERATIONS FOR MEMS-SCALE PIEZOELECTRIC MECHANICAL VIBRATION ENERGY HARVESTERS

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

70

Narrow bandwidth is the major challenge to today’s vibration-based energy harvesters. Compared with other broadband approaches that involve moving parts and control electronics, a double-mass piezoelectric cantilever beam provides a simple and reliable solution to widen the effective bandwidth as a vibration energy harvester. In this article, a continuum model of a double-mass lead zirconate titanate cantilever subject to sinusoidal

Qing Ou; XiaoQi Chen; Stefanie Gutschmidt; Alan Wood; Nigel Leigh; Andres F Arrieta

2012-01-01

71

We developed an asymmetric gammadion spring electrode for wide band vibration as a counter electrode for the electret electrode film of a micro electrostatic energy harvester. A vibration-driven micro power generator with a high-Q mechanical resonator works efficiently under single-frequency vibration, but, the associated narrow operation frequency bandwidth tightly limits the power output under normal wideband vibrations. To solve this

Takafumi Suzuki; Sumito Nagasawa; Hiroshi Okamoto; Hiroki Kuwano

2010-01-01

72

NASA Astrophysics Data System (ADS)

A hair-cell structure based piezoelectric energy harvester was newly developed to effectively scavenge three-dimensional vibrations. The cantilever of the proposed energy harvester, called a hair-cell structure, is deliberately elongated and curled so that it oscillates with decent displacement under not only vertically induced vibrations, but also under longitudinally and horizontally induced vibrations. The proposed energy harvester is comprised of an elongated and curled piezoelectric cantilever and a proof mass with high aspect ratio at the free end of the cantilever. The fabricated device generated the peak output voltage of 15 mV under vertically induced vibrations with an acceleration of 50 m/s2 at its resonance frequency of 116 Hz. Furthermore, it also generated the peak output voltage of 33 mV and 10 mV under longitudinally and horizontally induced vibrations, respectively.

Park, H.; Na, Y.; Park, J.; Park, J. Y.

2013-12-01

73

A wideband vibration energy harvester based on a folded asymmetric gapped cantilever

NASA Astrophysics Data System (ADS)

This paper reports a wideband multi-mass multi-spring piezoelectric vibration energy harvester (VEH) based on a folded asymmetric gapped cantilever, which enables multiple resonant modes formed by pure bending of every stage. Moreover, the heaviest proof mass is placed at the last stage of the cantilever to increase the harvested power. The VEH's energy conversion efficiency is further increased using the asymmetric gapped structure. A prototype has been developed and characterized. The experimental results match with finite element simulation well. The prototype was tested on an air conditioning unit to demonstrate its energy harvesting capability with a realistic broadband vibration source.

Hu, Yating; Xu, Yong

2014-02-01

74

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

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

75

MEMS Vibration Energy Harvesting Devices With Passive Resonance Frequency Adaptation Capability

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

76

A hybrid indoor ambient light and vibration energy harvester for wireless sensor nodes.

To take advantage of applications where both light and vibration energy are available, a hybrid indoor ambient light and vibration energy harvesting scheme is proposed in this paper. This scheme uses only one power conditioning circuit to condition the combined output power harvested from both energy sources so as to reduce the power dissipation. In order to more accurately predict the instantaneous power harvested from the solar panel, an improved five-parameter model for small-scale solar panel applying in low light illumination is presented. The output voltage is increased by using the MEMS piezoelectric cantilever arrays architecture. It overcomes the disadvantage of traditional MEMS vibration energy harvester with low voltage output. The implementation of the maximum power point tracking (MPPT) for indoor ambient light is implemented using analog discrete components, which improves the whole harvester efficiency significantly compared to the digital signal processor. The output power of the vibration energy harvester is improved by using the impedance matching technique. An efficient mechanism of energy accumulation and bleed-off is also discussed. Experiment results obtained from an amorphous-silicon (a-Si) solar panel of 4.8 × 2.0 cm2 and a fabricated piezoelectric MEMS generator of 11 × 12.4 mm2 show that the hybrid energy harvester achieves a maximum efficiency around 76.7%. PMID:24854054

Yu, Hua; Yue, Qiuqin; Zhou, Jielin; Wang, Wei

2014-01-01

77

A Hybrid Indoor Ambient Light and Vibration Energy Harvester for Wireless Sensor Nodes

To take advantage of applications where both light and vibration energy are available, a hybrid indoor ambient light and vibration energy harvesting scheme is proposed in this paper. This scheme uses only one power conditioning circuit to condition the combined output power harvested from both energy sources so as to reduce the power dissipation. In order to more accurately predict the instantaneous power harvested from the solar panel, an improved five-parameter model for small-scale solar panel applying in low light illumination is presented. The output voltage is increased by using the MEMS piezoelectric cantilever arrays architecture. It overcomes the disadvantage of traditional MEMS vibration energy harvester with low voltage output. The implementation of the maximum power point tracking (MPPT) for indoor ambient light is implemented using analog discrete components, which improves the whole harvester efficiency significantly compared to the digital signal processor. The output power of the vibration energy harvester is improved by using the impedance matching technique. An efficient mechanism of energy accumulation and bleed-off is also discussed. Experiment results obtained from an amorphous-silicon (a-Si) solar panel of 4.8 × 2.0 cm2 and a fabricated piezoelectric MEMS generator of 11 × 12.4 mm2 show that the hybrid energy harvester achieves a maximum efficiency around 76.7%.

Yu, Hua; Yue, Qiuqin; Zhou, Jielin; Wang, Wei

2014-01-01

78

Membrane-type vibrational energy harvester based on a multi-layered piezoelectric membrane

NASA Astrophysics Data System (ADS)

In this study, we fabricated a membrane-type vibrational energy harvester by using a conventional micro-electro-mechanical (MEMS) method. The membrane-type vibrational energy harvester consists of a multi-layered diaphragm for stable and flexible vibration, a piezoelectric ZnO film for responding to the vibrational energy and for generating electric power, and a vibrator connected to the bottom of multi-layered diaphragm for enhancing the vibrational displacement of the diaphragm. First, we characterized the quality of a ZnO film through scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD), which showed a preferred c-axis orientation, a hexagonal rod shape and a quite smooth surface. After the membrane-type vibrational energy harvester had been fabricated, we integrated it into a printing circuit board to realize piezoelectric generation and confirm its performance. Finally, under vibrational motion, we obtained a useful output voltage of 400 mV, and we estimated that the energy harvester generated an actual output voltage of about 200 uV.

Yoo, Seunghwan; Kim, Jonghun; Park, Suk-in; Jang, Cheol-Yong; Jeong, Hakgeun

2014-03-01

79

Design of nonlinear springs for wideband magnetic vibration energy harvester

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

80

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

81

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

82

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

83

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

84

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

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

85

Frequency Up-Converted Low Frequency Vibration Energy Harvester Using Trampoline Effect

NASA Astrophysics Data System (ADS)

This paper presents a non-resonant vibration energy harvester based on magnetoelectric transduction mechanism and mechanical frequency up-conversion using trampoline effect. The harvester utilizes a freely movable spherical permanent magnet which bounces off the aluminum springs integrated at both ends of the cavity, achieving frequency up-conversion from low frequency input vibration. Moreover, bonding method of magnetoelectric laminate composite has been optimized to provide higher strain to piezoelectric material and thus obtain a higher output voltage. A proof-of-concept energy harvesting device has been fabricated and tested. Maximum open-circuit voltage of 11.2V has been obtained and output power of 0.57?W has been achieved for a 50k? load, when the fabricated energy harvester was hand-shaken.

Ju, S.; Chae, S. H.; Choi, Y.; Jun, S.; Park, S. M.; Lee, S.; Lee, H. W.; Ji, C.-H.

2013-12-01

86

NASA Astrophysics Data System (ADS)

Increasing demand in mobile, autonomous devices has made energy harvesting a particular point of interest. Systems that can be powered up by a few hundreds of microwatts could feature their own energy extraction module. Energy can be harvested from the environment close to the device. Particularly, the ambient mechanical vibrations conversion via piezoelectric transducers is one of the most investigated fields for energy harvesting. A technique for optimized energy harvesting using piezoelectric actuators called "Synchronized Switching Harvesting" is explored. Comparing to a typical full bridge rectifier, the proposed harvesting technique can highly improve harvesting efficiency, even in a significantly extended frequency window around the piezoelectric actuator's resonance. In this paper, the concept of design, theoretical analysis, modeling, implementation and experimental results using CEDRAT's APA 400M-MD piezoelectric actuator are presented in detail. Moreover, we suggest design guidelines for optimum selection of the storage unit in direct relation to the characteristics of the random vibrations. From a practical aspect, the harvesting unit is based on dedicated electronics that continuously sense the charge level of the actuator's piezoelectric element. When the charge is sensed, to come to a maximum, it is directed to speedily flow into a storage unit. Special care is taken so that electronics operate at low voltages consuming a very small amount of the energy stored. The final prototype developed includes the harvesting circuit implemented with miniaturized, low cost and low consumption electronics and a storage unit consisting of a super capacitors array, forming a truly self-powered system drawing energy from ambient random vibrations of a wide range of characteristics.

Tsampas, P.; Roditis, G.; Papadimitriou, V.; Chatzakos, P.; Gan, Tat-Hean

2013-05-01

87

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

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

2011-01-01

88

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

89

Conversion of ambient vibrational energy into electric power has been the impetus of much modern research. The traditional analysis has focused on absolute electrical power output from the harvesting devices and efficiency defined as the convertibility of an infinite resource of vibration excitation into power. This perspective has limited extensibility when applying resonant harvesters to host resonant structures when the inertial influence of the harvester is more significant. Instead, this work pursues a fundamental understanding of the coupled dynamics of a main mass-spring-damper system to which an electromagnetic or piezoelectric mass-spring-damper is attached. The governing equations are derived, a metric of efficiency is presented, and analysis is undertaken. It is found that electromagnetic energy harvesting efficiency and maximum power output is limited by the strength of the coupling such that no split system resonances are induced for a given mass ratio. For piezoelectric harvesters, only the coupling strength and certain design requirements dictate maximum power and efficiency achievable. Since the harvesting circuitry must "follow" the split resonances as the piezoelectric harvesters become more massive, the optimum design of piezoelectric harvesters appears to be more involved than for electromagnetic devices. PMID:22779465

Harne, Ryan L

2012-07-01

90

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

Junhui Hu; Januar Jong; Chunsheng Zhao

2010-01-01

91

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

92

Self-powered autonomous wireless sensor node using vibration energy harvesting

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

93

Scavenging vibration energy from seismically isolated bridges using an electromagnetic harvester

NASA Astrophysics Data System (ADS)

The increasing worldwide efforts in securing renewable energy sources increase incentive for civil engineers to investigate whether the kinetic energy associated with the vibration of larger-scale structures can be harvested. Such a research remains challenging and incomplete despite that hundreds of related articles have been published in the last decade. Base isolation is one of the most popular means of protecting a civil engineering structure against earthquake forces. Seismic isolation hinges on the decoupling of the structure from the shaking ground, hence protecting the structure from stress and damage during an earthquake excitation. The low stiffness isolator inserted between the structure and the ground dominates the response leading to a structural system of longer vibration period. As a consequence of this period shift, the spectral acceleration is reduced, but higher response displacements are produced. To mitigate this side effect, usually isolators are combined with the use of additional energy dissipation. In this study, the feasibility of scavenging the need-to-be dissipated energy from the isolator installed in a seismically isolated bridge using an electromagnetic (EM) energy harvester is investigated. The EM energy harvester consists of an energy harvesting circuit and a capacitor for energy storage. A mathematical model for this proposed EM energy harvester is developed and implemented on an idealized base-isolated single-degree-of-freedom system. The effect of having this EM energy harvester on the performance of this seismic isolated system is analyzed and discussed. The potential of installing such an EM energy harvester on a seismically isolated bridge is also addressed.

Lu, Qiuchen; Loong, Chengning; Chang, Chih-Chen; Dimitrakopoulos, Elias G.

2014-04-01

94

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

95

NASA Astrophysics Data System (ADS)

A mass-spring-damper system is at the core of both a vibration absorber and a harvester of energy from ambient vibrations. If such a device is attached to a structure that has a high impedance, then it will have very little effect on the vibrations of the structure, but it can be used to convert mechanical vibrations into electrical energy (act as an energy harvester). However, if the same device is attached to a structure that has a relatively low impedance, then the device may attenuate the vibrations as it may act as both a vibration absorber and an energy harvester simultaneously. In this paper such a device is discussed. Two situations are considered; the first is when the structure is excited with broadband random excitation and the second is when the structure is excited by a single frequency. The optimum parameters of the device for both energy harvesting and vibration attenuation are discussed for these two cases. For random excitation it is found that if the device is optimized for vibration suppression, then this is also adequate for maximizing the energy absorbed (harvested), and thus a single device can effectively suppress vibration and harvest energy at the same time. For single frequency excitation this is found not to be the case. To maximize the energy harvested, the natural frequency of the system (host structure and absorber) has to coincide with the forcing frequency, but to minimize vibration of the host structure, the natural frequency of the absorber has to coincide with the forcing frequency. In this case, therefore, a single resonator cannot effectively suppress vibration and harvest energy at the same time.

Brennan, M. J.; Tang, B.; Melo, G. Pechoto; Lopes, V.

2014-02-01

96

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

97

Non-resonant electromagnetic wideband energy harvesting mechanism for low frequency vibrations

A novel non-resonant energy harvesting mechanism with wide operation frequency band is investigated for collecting energy\\u000a from low frequency ambient vibration. A free-standing magnet is packaged inside a sealed hole which is created by stacking\\u000a five pieces of printed circuit board substrates embedded with multi-layer copper coils. This device was tested under various\\u000a acceleration conditions. Considering the air damping effect,

Bin Yang; Chengkuo Lee

2010-01-01

98

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

99

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

100

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

101

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

102

Analysis of Nonlinear Spring Arm for Improved Performance of Vibrational Energy Harvesting Devices

NASA Astrophysics Data System (ADS)

Recently, a number of attempts have been made to increase the operational bandwidth of the energy harvesting devices. Nonlinear mechanisms are one of them. In this paper, we report design and analytical formulation of stretching strain of an electromagnetic energy harvester on FR4 material under large deformation of the spring arms. It is found that nonlinearity has an inverse square dependence on thickness of the arms. Numerical solution of a monostable Duffing oscillator that governs the dynamics of such a large deformed nonlinear energy harvester showed that with decrease of load resistance, the average power output increases, where the output response depends strongly on the input force. For small input acceleration, the desired large amplitude vibration does not come into play and the response becomes linear. However, for higher input acceleration nonlinearity appears and the operational bandwidth increases, at the same time, output power level also increases.

Mallick, D.; Amann, A.; Roy, S.

2013-12-01

103

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

104

NASA Astrophysics Data System (ADS)

The need for reduced power requirements for small electronic components, such as wireless sensor networks, has prompted interest in recent years for energy harvesting technologies capable of capturing energy from broadband ambient vibrations. Encouraging results have been reported for an arrangement of piezoelectric layers attached to carbon fiber / epoxy laminates which possess bistability by virtue of their specific asymmetric stacking sequence. 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. Existing studies, both experimental and modelling, have been limited to simple geometric laminate shapes, restricting the scope for improved energy harvesting performance by limiting the number of design variables. In this paper we present an analytical model to predict the static shapes of laminates of any desired profile, validated experimentally using a digital image correlation system. Good accuracy in terms of out-of-plane displacements (5-7%) are shown in line with existing square modelling results. The static model is then mapped to a dynamics model and used to compare results against an experimental study of the harvesting performance of an example arbitrary geometry piezoelectric-laminate energy harvester.

Betts, David N.; Bowen, Christopher R.; Inman, Daniel J.; Weaver, Paul M.; Kim, H. A.

2014-04-01

105

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

106

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. PMID:21200444

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

2010-12-01

107

NASA Astrophysics Data System (ADS)

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.

2010-12-01

108

This study was performed to investigate the effectiveness of submerged microfiltration to harvest both a marine diatom Phaeodactylum tricornutum and a Chlorella vulgaris in a recently developed magnetically induced membrane vibrating (MMV) system. We assess the filtration performance by conducting the improved flux step method (IFM), fed-batch concentration filtrations and membrane fouling autopsy using two lab-made membranes with different porosity. The full-scale energy consumption was also estimated. Overall results suggest that the MMV offers a good fouling control and the process was proven to be economically attractive. By combining the membrane filtration (15× concentration) with centrifugation to reach a final concentration of 25% w/v, the energy consumption to harvest P. tricornutum and C. vulgaris was, respectively, as low as 0.84 and 0.77kWh/m(3), corresponding to 1.46 and 1.39 kWh/kg of the harvested biomass. PMID:23624051

Bilad, M R; Discart, V; Vandamme, D; Foubert, I; Muylaert, K; Vankelecom, Ivo F J

2013-06-01

109

NASA Astrophysics Data System (ADS)

An electromagnetic kinetic energy harvester has been developed, which can convert ultra-low-frequency motion and vibration energy into electrical power. This harvester employs a two-stage vibratory structure to collect low-frequency kinetic energy and effectively transfer it into electric power by using a pair of high-frequency resonant generators. Non-contact magnetic repulsive force is herein utilized for the 1st-stage sliding vibrator to drive the 2nd-stage resonators into frequency-up-conversion resonance. The non-contact actuation is helpful for durable and long-life working of the device. The prototyped device is fabricated and the design is well confirmed by experimental test. The harvester can be well operated at the frequency as low as 0.25 Hz. Under driving acceleration of 1 g at 0.5 Hz, the miniaturized harvester can generate a peak power of 4.42 mW and an average power of 158 ?W.

Tang, Qiaochu; Yang, Yongliang; Li, Xinxin

2014-04-01

110

An electromagnetic kinetic energy harvester has been developed, which can convert ultra-low-frequency motion and vibration energy into electrical power. This harvester employs a two-stage vibratory structure to collect low-frequency kinetic energy and effectively transfer it into electric power by using a pair of high-frequency resonant generators. Non-contact magnetic repulsive force is herein utilized for the 1st-stage sliding vibrator to drive the 2nd-stage resonators into frequency-up-conversion resonance. The non-contact actuation is helpful for durable and long-life working of the device. The prototyped device is fabricated and the design is well confirmed by experimental test. The harvester can be well operated at the frequency as low as 0.25 Hz. Under driving acceleration of 1 g at 0.5 Hz, the miniaturized harvester can generate a peak power of 4.42 mW and an average power of 158 ?W. PMID:24784650

Tang, Qiaochu; Yang, Yongliang; Li, Xinxin

2014-04-01

111

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

112

A micromachined low-frequency piezoelectric harvester for vibration and wind energy scavenging

NASA Astrophysics Data System (ADS)

To efficiently scavenge ambient vibration energy and wind energy at the same time, a low-frequency piezoelectric harvester was designed, fabricated and tested. A lumped-parameter model of the cantilevered piezoelectric energy harvester with a proof mass was established and the closed-form expressions of voltage and power on a resistance load under base acceleration excitation were derived. After effects of the lengths of the proof mass and electrodes on output power were analyzed, a MEMS harvester was optimally designed. By using aluminum nitride as piezoelectric layer, a MEMS energy harvester was fabricated with bulk micromachining process. Experimental results show that the open-circuit frequency of the MEMS harvester is about 134.8 Hz and the matched resistance is about 410 k?. Under the harmonic acceleration excitation of ±0.1 g, the maximum output power is about 1.85 µW, with the normalized power density of about 6.3 mW cm-3 g-2. The critical wind speed of the device is between 12.7 and 13.2 m s-1 when the wind direction is from the proof mass to the fixed end of the cantilever. The maximum output power under 16.3 m s-1 wind is about 2.27 µW.

He, Xuefeng; Shang, Zhengguo; Cheng, Yaoqing; Zhu, You

2013-12-01

113

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

114

Harvesting broadband kinetic impact energy from mechanical triggering/vibration and water waves.

We invented a triboelectric nanogenerator (TENG) that is based on a wavy-structured Cu-Kapton-Cu film sandwiched between two flat nanostructured PTFE films for harvesting energy due to mechanical vibration/impacting/compressing using the triboelectrification effect. This structure design allows the TENG to be self-restorable after impact without the use of extra springs and converts direct impact into lateral sliding, which is proved to be a much more efficient friction mode for energy harvesting. The working mechanism has been elaborated using the capacitor model and finite-element simulation. Vibrational energy from 5 to 500 Hz has been harvested, and the generator's resonance frequency was determined to be ?100 Hz at a broad full width at half-maximum of over 100 Hz, producing an open-circuit voltage of up to 72 V, a short-circuit current of up to 32 ?A, and a peak power density of 0.4 W/m(2). Most importantly, the wavy structure of the TENG can be easily packaged for harvesting the impact energy from water waves, clearly establishing the principle for ocean wave energy harvesting. Considering the advantages of TENGs, such as cost-effectiveness, light weight, and easy scalability, this approach might open the possibility for obtaining green and sustainable energy from the ocean using nanostructured materials. Lastly, different ways of agitating water were studied to trigger the packaged TENG. By analyzing the output signals and their corresponding fast Fourier transform spectra, three ways of agitation were evidently distinguished from each other, demonstrating the potential of the TENG for hydrological analysis. PMID:24964297

Wen, Xiaonan; Yang, Weiqing; Jing, Qingshen; Wang, Zhong Lin

2014-07-22

115

Self-powered resonant frequency tuning for Piezoelectric Vibration Energy Harvesters

NASA Astrophysics Data System (ADS)

This paper reports on the design, fabrication and testing of an innovative 33-mode piezoelectric vibration energy harvester (VEH). This system is able to change its resonant frequency in real time to follow the main frequency of a vibration source. The system proposed in this paper enables to adapt VEH characteristics (resonant frequency, electrical damping) to vibration parameters variations (frequency and amplitude) in order to optimize the extraction of energy and then the output power at any time. This solution allows up to 40% of resonant frequency tuning ratio; moreover, the adaptation is made in real time and the consumption of the regulation electronic is less than 10% of the VEH output power (480?W@0.1g-276Hz).

Ahmed-Seddik, B.; Despesse, G.; Boisseau, S.; Defay, E.

2013-12-01

116

Multi-modal vibration based MEMS energy harvesters for ultra-low power wireless functional nodes

NASA Astrophysics Data System (ADS)

The aim of this contribution is to report and discuss a preliminary study and rough optimization of a novel concept of MEMS device for vibration energy harvesting, based on a multi-modal dynamic behavior. The circular-shaped device features Four-Leaf Clover-like (FLC) double spring-mass cascaded systems, kept constrained to the surrounding frame by means of four straight beams. The combination of flexural bending behavior of the slender beams plus deformable parts of the petals enable to populate the desired vibration frequency range with a number of resonant modes, and improve the energy conversion capability of the micro-transducer. The harvester device, conceived for piezoelectric mechanical into electric energy conversion, is intended to sense environmental vibrations and, thereby, its geometry is optimized to have a large concentration of resonant modes in a frequency range below 5-10 kHz. The results of FEM (Finite Element Method) based analysis performed in ANSYSTM Workbench are reported, both concerning modal and harmonic response, providing important indications related to the device geometry optimization. The analysis reported in this work is limited to the sole mechanical modeling of the proposed MEMS harvester device concept. Future developments of the study will encompass the inclusion of piezoelectric conversion in the FEM simulations, in order to have indications of the actual power levels achievable with the proposed harvester concept. Furthermore, the results of the FEM studies here discussed, will be validated against experimental data, as soon as the MEMS resonator specimens, currently under fabrication, are ready for testing.

Iannacci, J.; Gottardi, M.; Serra, E.; Di Criscienzo, R.; Borrielli, A.; Bonaldi, M.

2013-05-01

117

Electromagnetic Vibration Energy Harvester Using Springless Proof Mass and Ferrofluid as a Lubricant

NASA Astrophysics Data System (ADS)

This paper presents an electromagnetic energy harvester using an array of rectangular permanent magnets as springless proof mass and ferrofluid as a lubricating material. Lateral motion of the multi-pole magnet array generates voltage across an array of copper windings formed under the aluminum channel in response to low frequency external vibrations such as human-body-induced motion. A proof-of-concept device has been fabricated and output voltage has been measured at various input frequencies and accelerations provided by a vibration exciter. Device with ferrofluid lubrication generated maximum open-circuit voltage of 0.47V at 3g vibration at 12Hz, which is 8% higher than that of the device without lubricant. Maximum output power of 71.26?W has been obtained at 40.8? with the device with ferrofluid lubrication.

Chae, S. H.; Ju, S.; Choi, Y.; Jun, S.; Park, S. M.; Lee, S.; Lee, H. W.; Ji, C.-H.

2013-12-01

118

NASA Astrophysics Data System (ADS)

Due to their two-way electromechanical coupling effect, piezoelectric transducers can be used to synthesize passive vibration control schemes, e.g., RLC circuit with the integration of inductance and resistance elements that is conceptually similar to damped vibration absorber. Meanwhile, the wide usage of wireless sensors has led to the recent enthusiasm of developing piezoelectric-based energy harvesting devices that can convert ambient vibratory energy into useful electrical energy. It can be shown that the integration of circuitry elements such as resistance and inductance can benefit the energy harvesting capability. Here we explore a dual-purpose circuit that can facilitate simultaneous vibration suppression and energy harvesting. It is worth noting that the goal of vibration suppression and the goal of energy harvesting may not always complement each other. That is, the maximization of vibration suppression doesn't necessarily lead to the maximization of energy harvesting, and vice versa. In this research, we develop a fuzzy-logic based algorithm to decide the proper selection of circuitry elements to balance between the two goals. As the circuitry elements can be online tuned, this research yields an adaptive circuitry concept for the effective manipulation of system energy and vibration suppression. Comprehensive analyses are carried out to demonstrate the concept and operation.

Liu, Zhe Peng; Li, Qing

2013-04-01

119

A review of the recent research on vibration energy harvesting via bistable systems

NASA Astrophysics Data System (ADS)

The investigation of the conversion of vibrational energy into electrical power has become a major field of research. In recent years, bistable energy harvesting devices have attracted significant attention due to some of their unique features. Through a snap-through action, bistable systems transition from one stable state to the other, which could cause large amplitude motion and dramatically increase power generation. Due to their nonlinear characteristics, such devices may be effective across a broad-frequency bandwidth. Consequently, a rapid engagement of research has been undertaken to understand bistable electromechanical dynamics and to utilize the insight for the development of improved designs. This paper reviews, consolidates, and reports on the major efforts and findings documented in the literature. A common analytical framework for bistable electromechanical dynamics is presented, the principal results are provided, the wide variety of bistable energy harvesters are described, and some remaining challenges and proposed solutions are summarized.

Harne, R. L.; Wang, K. W.

2013-02-01

120

A vibration-based MEMS piezoelectric energy harvester and power conditioning circuit.

This paper presents a micro-electro-mechanical system (MEMS) piezoelectric power generator array for vibration energy harvesting. A complete design flow of the vibration-based energy harvester using the finite element method (FEM) is proposed. The modal analysis is selected to calculate the resonant frequency of the harvester, and harmonic analysis is performed to investigate the influence of the geometric parameters on the output voltage. Based on simulation results, a MEMS Pb(Zr,Ti)O3 (PZT) cantilever array with an integrated large Si proof mass is designed and fabricated to improve output voltage and power. Test results show that the fabricated generator, with five cantilever beams (with unit dimensions of about 3 × 2.4 × 0.05 mm3) and an individual integrated Si mass dimension of about 8 × 12.4 × 0.5 mm3, produces a output power of 66.75 ?W, or a power density of 5.19 ?W?mm-3?g-2 with an optimal resistive load of 220 k? from 5 m/s2 vibration acceleration at its resonant frequency of 234.5 Hz. In view of high internal impedance characteristic of the PZT generator, an efficient autonomous power conditioning circuit, with the function of impedance matching, energy storage and voltage regulation, is then presented, finding that the efficiency of the energy storage is greatly improved and up to 64.95%. The proposed self-supplied energy generator with power conditioning circuit could provide a very promising complete power supply solution for wireless sensor node loads. PMID:24556670

Yu, Hua; Zhou, Jielin; Deng, Licheng; Wen, Zhiyu

2014-01-01

121

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

122

NASA Astrophysics Data System (ADS)

A magnetoelectric (ME) vibration energy harvester has been designed to scavenge sufficient energy from ambient vibration with arbitrary motion directions in a plane and over a range of frequencies. In the harvester, a circular-cross-section cantilever rod is adopted to extract the vibration energy due to its ability to host accelerations in arbitrary in-plane motion directions. The magnetic coupling between the magnet and the ME transducer results in nonlinear oscillation of the cantilever rod with increased frequency bandwidth. To achieve optimal vibration energy harvesting performance, the effects of the nonlinear vibration and the harvester parameters including the magnetic circuit and the separation distance on the electrical output and the?working bandwidth are analyzed. The experimental results show that the harvester can scavenge vibration energy in arbitrary in-plane directions, exhibiting a bandwidth of 4.0 Hz and maximum power of 0.22 mW at acceleration of 0.6 g (with g = 9.8 m s-2).

Yang, Jin; Wen, Yumei; Li, Ping; Yue, Xihai; Yu, Qiangmo

2014-07-01

123

NASA Astrophysics Data System (ADS)

A magnetoelectric (ME) vibration energy harvester has been designed to scavenge sufficient energy from ambient vibration with arbitrary motion directions in a plane and over a range of frequencies. In the harvester, a circular-cross-section cantilever rod is adopted to extract the vibration energy due to its ability to host accelerations in arbitrary in-plane motion directions. The magnetic coupling between the magnet and the ME transducer results in nonlinear oscillation of the cantilever rod with increased frequency bandwidth. To achieve optimal vibration energy harvesting performance, the effects of the nonlinear vibration and the harvester parameters including the magnetic circuit and the separation distance on the electrical output and the?working bandwidth are analyzed. The experimental results show that the harvester can scavenge vibration energy in arbitrary in-plane directions, exhibiting a bandwidth of 4.0 Hz and maximum power of 0.22 mW at acceleration of 0.6g (with g = 9.8 m s-2).

Yang, Jin; Wen, Yumei; Li, Ping; Yue, Xihai; Yu, Qiangmo

2014-05-01

124

NASA Astrophysics Data System (ADS)

In recent years, an increasing number of breakthroughs have been made in the field of small-scale wind energy harvesting, where specialized materials are utilized to convert flow energy into electric power. Several studies on this power extraction rely on a common energy harvester setup in which a stiff cantilever beam is attached to the trailing edge of a miniature bluff body. At these small scales where boundary layer effects are appreciable in the laminar flow regime, periodic vortex shedding can be used to drive transverse vibrations in the beam. Interestingly, the fluid dynamics involved in this unsteady process have been studied for decades not to exploit their characteristics, but instead to eliminate potentially destructive effects. As a result, there is still much room for improvement and expansion on recent design studies. A study of how subtle changes in bluff body trailing edge geometry effect power output of a model will be presented in this paper. The model under consideration consists of a miniature bluff body on the order of tens of millimeters in diameter, to which a piezoelectric cantilever is attached at the trailing edge. This model is specifically designed for laminar to transitional Reynolds Number flows (500-2800) where the periodicity of vortex shedding approaches the natural frequency of the beam. As the flow speed is further increased, the effect of lock-in occurs where the resonant beam motion resists a change in vortex shedding frequency. Vibration amplitudes of the beam reach a maximum under this condition, thus maximizing power generation efficiency of the system and providing an optimal condition to operate the harvester. In an effort to meaningfully compare the results, a number of dimensionless parameters are employed. The influence of parameters such as beam length and natural frequency, fluid flow speed, and trailing edge geometry are studied utilizing COMSOL Multiphysics laminar, fluid-structure interaction simulations in order to create design guidelines for an improved energy harvester.

Paxson, Benjamin; Wickenheiser, Adam M.

2014-04-01

125

NASA Astrophysics Data System (ADS)

This paper presents analytical modeling and case studies of broadband and band-limited random vibration energy harvesting using a piezoceramic patch attached on a thin plate. The literature of vibration-based energy harvesting has been mostly focused on resonant cantilevered structures. However, cantilevered beam-type harvesters have limited broadband vibration energy harvesting capabilities unless they are combined with a nonlinear component. Moreover, cantilever arrangements cannot always be mounted on thin structures (which are basic components of marine, aerospace, and ground transportation systems) without significantly affecting the host system's design and overall dynamics. A patch-based piezoelectric energy harvester structurally integrated to a thin plate can be a proper alternative to using resonant cantilevers for harvesting energy from thin structures. Besides, plate-like structures have more number of vibration modes compared to beam structures, offering better broadband performance characteristics. In this paper, we present analytical modelling of patch-based piezoelectric energy harvester attached on a thin plate for random vibrations. The analytical model is based on electromechanically-coupled distributed-parameter formulation and validated by comparing the electromechanical frequency response functions (FRFs) with experimental results. Example case studies are then presented to investigate the expected power output of a piezoceramic patch attached on an aluminum plate for the case of random force excitations. The effect of bandwidth of random excitation on the mean power and shunted mean-square vibration response are explored with a focus on the number of vibration modes covered in the frequency range of input power spectral density (PSD).

Aridogan, Ugur; Basdogan, Ipek; Erturk, Alper

2014-04-01

126

NASA Astrophysics Data System (ADS)

Vibrational energy harvesting devices are often designed in a manner analogous to classical dynamic vibration absorbers (DVAs). An electromechanical mass-spring system is devised so as to resonate at the frequency most dominant in the environmental vibration spectrum; the consequent device oscillation is converted to a electrical signal which is harnessed for immediate usage or as a charging mechanism for a battery. The DVA is likewise designed but with the intention of inducing substantial inertial influence upon a host structure for vibration control purposes, either to globally dampen the vibration of the main body or, in an undamped configuration to "absorb" the primary system vibration at a single frequency. This paper describes the development of an electromechanical mass-spring-damper which seeks to serve both goals of passive vibration control and energy harvesting. The device utilizes a piezoelectric film spring and a distributed mass layer so as to be suitable for the attenuation of surface vibrations and to convert a portion of the absorbed energy into electric power. The development and design of the device are presented and the results of realistic tests are provided to show both the potentials and the challenges encountered when attempting to superpose the goals of vibration control and energy harvesting.

Harne, R. L.

2013-04-01

127

NASA Astrophysics Data System (ADS)

A vibration energy harvester designed to access parametric resonance can potentially outperform the conventional direct resonant approach in terms of power output achievable given the same drive acceleration. Although linear damping does not limit the resonant growth of parametric resonance, a damping dependent initiation threshold amplitude exists and limits its onset. Design approaches have been explored in this paper to passively overcome this limitation in order to practically realize and exploit the potential advantages. Two distinct design routes have been explored, namely an intrinsically lower threshold through a pendulum-lever configuration and amplification of base excitation fed into the parametric resonator through a cantilever-initial-spring configuration. Experimental results of the parametric resonant harvesters with these additional enabling designs demonstrated an initiation threshold up to an order of magnitude lower than otherwise, while attaining a much higher power peak than direct resonance.

Jia, Yu; Yan, Jize; Soga, Kenichi; Seshia, Ashwin A.

2014-06-01

128

Semi-active controller design for vibration suppression and energy harvesting via LMI approach

NASA Astrophysics Data System (ADS)

The vibration control plays an important role in energy harvesting systems. Compared to the active control, semi-active control is a more preferred alternative for practical use. Many different semi-active control strategies have been developed, among which LQ-clip, Skyhook and model predictive control are the most popular strategies in literatures. In this paper, a different control strategy that designs semi-active controller via LMI approach is proposed. Different from clipping the control input after controller construction like most existing control methods, the proposed method fulfills the semi-active control input feasibility constraints before the controller construction. The methodology is developed through LMI approach which leads to a stabilizing linear controller to ensure semi-active constraint and the pre-designed performance. An illustrative example, vibration control system of a tall building, is presented to show the efficiency of the method and validate the new approach.

Liu, Yilun; Lin, Chi-Chang; Zuo, Lei

2014-04-01

129

NASA Astrophysics Data System (ADS)

Regenerative semi-active suspensions can capture the previously dissipated vibration energy and convert it to usable electrical energy for powering on-board electronic devices, while achieve both the better ride comfort and improved road handling performance at the same time when certain control is applied. To achieve this objective, the power electronics interface circuit connecting the energy harvester and the electrical loads, which can perform simultaneous vibration control and energy harvesting function is in need. This paper utilized a buck-boost converter for simultaneous semi-active vibration control and energy harvesting with electromagnetic regenerative shock absorber, which utilizes a rotational generator to converter the vibration energy to electricity. It has been found that when the circuit works in discontinuous current mode (DCM), the ratio between the input voltage and current is only related to the duty cycle of the switch pulse width modulation signal. Using this property, the buck-boost converter can be used to perform semi-active vibration control by controlling the load connected between the terminals of the generator in the electromagnetic shock absorber. While performing the vibration control, the circuit always draw current from the shock absorber and the suspension remain dissipative, and the shock absorber takes no additional energy to perform the vibration control. The working principle and dynamics of the circuit has been analyzed and simulations were performed to validate the concept.

Li, Peng; Zhang, Chongxiao; Kim, Junyoung; Yu, Liangyao; Zuo, Lei

2014-04-01

130

Power harvesters from mechanical vibrations are commonly linear mechanical resonators that are most efficient when excited at resonance. Differently, under wideband vibrations, linear converters are suboptimal. A nonlinear converter is here proposed that implements nonlinearity and bistability by employing one external magnet, in order to improve conversion effectiveness while simplifying device fabrication. The converter is composed of a piezoelectric bimorph

M. Ferrari; V. Ferrari; M. Guizzetti; D. Marioli

2010-01-01

131

Power harvesters from mechanical vibrations are commonly linear mechanical resonators that are most effective when excited at resonance. Differently, under wideband vibrations, linear converters are suboptimal. A nonlinear converter is here proposed that implements nonlinearity and bistability by employing a single external magnet, in order to improve conversion effectiveness while simplifying device fabrication. The converter is composed of a piezoelectric

M. Ferrari; M. Baù; M. Guizzetti; V. Ferrari

132

The simulation results for electromagnetic energy harvesters (EMEHs) under broad band stationary Gaussian random excitations indicate the importance of both a high transformation factor and a high mechanical quality factor to achieve favourable mean power, mean square load voltage, and output spectral density. The optimum load is different for random vibrations and for sinusoidal vibration. Reducing the total damping ratio under band-limited random excitation yields a higher mean square load voltage. Reduced bandwidth resulting from decreased mechanical damping can be compensated by increasing the electrical damping (transformation factor) leading to a higher mean square load voltage and power. Nonlinear EMEHs with a Duffing spring and with linear plus cubic damping are modeled using the method of statistical linearization. These nonlinear EMEHs exhibit approximately linear behaviour under low levels of broadband stationary Gaussian random vibration; however, at higher levels of such excitation the central (resonant) frequency of the spectral density of the output voltage shifts due to the increased nonlinear stiffness and the bandwidth broadens slightly. Nonlinear EMEHs exhibit lower maximum output voltage and central frequency of the spectral density with nonlinear damping compared to linear damping. Stronger nonlinear damping yields broader bandwidths at stable resonant frequency. PMID:24605063

Khan, Farid; Stoeber, Boris; Sassani, Farrokh

2014-01-01

133

The simulation results for electromagnetic energy harvesters (EMEHs) under broad band stationary Gaussian random excitations indicate the importance of both a high transformation factor and a high mechanical quality factor to achieve favourable mean power, mean square load voltage, and output spectral density. The optimum load is different for random vibrations and for sinusoidal vibration. Reducing the total damping ratio under band-limited random excitation yields a higher mean square load voltage. Reduced bandwidth resulting from decreased mechanical damping can be compensated by increasing the electrical damping (transformation factor) leading to a higher mean square load voltage and power. Nonlinear EMEHs with a Duffing spring and with linear plus cubic damping are modeled using the method of statistical linearization. These nonlinear EMEHs exhibit approximately linear behaviour under low levels of broadband stationary Gaussian random vibration; however, at higher levels of such excitation the central (resonant) frequency of the spectral density of the output voltage shifts due to the increased nonlinear stiffness and the bandwidth broadens slightly. Nonlinear EMEHs exhibit lower maximum output voltage and central frequency of the spectral density with nonlinear damping compared to linear damping. Stronger nonlinear damping yields broader bandwidths at stable resonant frequency.

Sassani, Farrokh

2014-01-01

134

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

135

Wind energy harvesting with a piezoelectric harvester

NASA Astrophysics Data System (ADS)

An energy harvester comprising a cantilever attached to piezoelectric patches and a proof mass is developed for wind energy harvesting, from a cross wind-induced vibration of the cantilever, by the electromechanical coupling effect of piezoelectric materials. The vibration of the cantilever under the cross wind is induced by the air pressure owing to a vortex shedding phenomenon that occurs on the leeward side of the cantilever. To describe the energy harvesting process, a theoretical model considering the cross wind-induced vibration on the piezoelectric coupled cantilever energy harvester is developed, to calculate the charge and the voltage from the harvester. The influences of the length and location of the piezoelectric patches as well as the proof mass on the generated electric power are investigated. Results show that the total generated electric power can be as high as 2 W when the resonant frequency of the cantilever harvester is close to the vortex shedding frequency. Moreover, a value of total generated electric power up to 1.02 W can be practically realized for a cross wind with a variable wind velocity of 9-10 m s-1 by a harvester with a length of 1.2 m. This research facilitates an effective and compact wind energy harvesting device.

Wu, Nan; Wang, Quan; Xie, Xiangdong

2013-09-01

136

NASA Astrophysics Data System (ADS)

This paper presents experimentally-verified multiphysics finite element model of a wideband vibration energy harvester with impact coupling, which operates on the principle of frequency up-conversion: under low-frequency harmonic base excitation a cantilever-type resonator (with resonant frequency of 18.8 Hz) impacts a high-frequency piezoelectric cantilever, which starts freely vibrate at its resonant frequency of 374 Hz. Such input frequency amplification enables efficient power generation under low-frequency ambient excitations. The model was implemented in COMSOL and the contact between the cantilevers was formulated by using a nonlinear viscoelastic model. Reported results of dynamical and electrical testing of the fabricated vibration energy harvester confirm the accuracy of the model as well as reveal some operational characteristics of the device under varying impact and excitation conditions.

Dauksevicius, R.; Briand, D.; Vásquez Quintero, A.; Lockhart, R. A.; Janphuang, P.; de Rooij, N. F.; Ostasevicius, V.

2013-12-01

137

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 the exploitation of the dynamical features of stochastic nonlinear oscillators. Such a method is shown to outperform standard linear oscillators and to overcome some of the most severe limitations of present approaches. We demonstrate the superior performances of this method by applying it to piezoelectric energy harvesting from ambient vibration. PMID:19257728

Cottone, F; Vocca, H; Gammaitoni, L

2009-02-27

138

NASA Astrophysics Data System (ADS)

The basic purpose of a damper is to reduce the vibration and to have a better ride comfort, road handling and safety to the rider. Recent developments show that an active vibration damper can effectively work much better than a passive damper. The effectiveness and reliability can be further enhanced by using hybrid dampers, which is a combination of active and passive dampers. But the need to have energy optimization in any field need not be stressed. Consequently, novel suspension concepts are required, not only to improve the vehicle's dynamic performance, but also to see that the energy generated during vibration can be harvested by utilizing regeneration functions. Hence if a hybrid damper with energy harvesting capability be designed, it would serve both purposes. In the hybrid damper a combination of hydraulic damper to act as a passive damper and an electromagnetic (EM) damper to act as an active damper is considered. The hydraulic system has more reliability and is time tested and the EM system acts as a dynamic vibration system as well as energy harvester. In this study a hybrid EM damper is modeled, analyzed and validity is shown for frequency response functions and energy balance for its active use. It is also shown how the effectiveness of the suspension system can be enhanced by using a hybrid damper.

Hanumantha Rao, T. V.; Srinivasa Rao, M. S. S.; Apparao, B. V.; Satyanarayana, K.

2014-04-01

139

A flex-compressive-mode piezoelectric transducer for mechanical vibration/strain energy harvesting.

A piezoelectric transducer for harvesting energy from ambient mechanical vibrations/strains under pressure condition was developed. The proposed transducer was made of two ring-type piezoelectric stacks, one pair of bow-shaped elastic plates, and one shaft that pre-compresses them. This transducer works in flex-compressive (F-C) mode, which is different from a conventional flex-tensional (F-T) one, to transfer a transversely applied force F into an amplified longitudinal force N pressing against the two piezo-stacks via the two bowshaped elastic plates, generating a large electric voltage output via piezoelectric effect. Our experimental results show that without an electric load, an F-C mode piezo-transducer could generate a maximum electric voltage output of up to 110 Vpp, and with an electric load of 40 ??, it a maximum power output of 14.6 mW under an acceleration excitation of 1 g peak-peak at the resonance frequency of 87 Hz. PMID:21507747

Li, Xiaotian; Guo, Mingsen; Dong, Shuxiang

2011-04-01

140

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

141

This research presents an experimental and theoretical energy harvesting characterization of beam-like, uniform cross-section, unimorph structures employing single-crystal piezoelectrics. Different piezoelectric materials, substrates, and configurations are examined to identify the best design configuration for lightweight energy harvesting devices for low-power applications. Three types of piezoelectrics (singlecrystal PMN-PZT, polycrystalline PZT-5A, and PZT-5H-type monolithic ceramics) are evaluated in a unimorph cantilevered beam configuration. The devices have been excited by harmonic base acceleration. All of the experimental characteristics have been used to validate an exact electromechanical model of the harvester. The study shows the optimum choice of substrate material for single-crystal piezoelectric energy harvesting. Comparison of energy scavengers with stainless steel substrates reveals that single-crystal harvesters produce superior power compared with polycrystalline devices. To further optimize the power harvesting, we study the relation between the thickness of the substrate and the power output for different substrate materials. The relation between power and substrate thickness profoundly varies among different substrate materials. The variation is understood by examining the change of mechanical transmissibility and the variations of the coupling figure of merit of the harvesters with thickness ratio. The investigation identifies the optimal thickness of the substrate for different substrate materials. The study also shows that the densities of the substrates and their mechanical damping coefficients have significant effects on the power output. PMID:21768034

Karami, M Amin; Bilgen, Onur; Inman, Daniel J; Friswell, Michael I

2011-07-01

142

An application of stochastic resonance for energy harvesting in a bistable vibrating system

NASA Astrophysics Data System (ADS)

The application of stochastic resonance to mechanical energy harvesting is currently of topical interest, and this paper concentrates on an analytical and experimental investigation in which stochastic resonance is deliberately exploited within a bistable mechanical system for optimised energy harvesting. The condition for the occurrence of stochastic resonance is defined conventionally by the Kramers rate, and the modelling of a theoretical nonlinear oscillator driven by a small periodic modulating excitation and a harvestable noise source, which, together satisfy this condition, is developed in the paper. A novel experiment is also discussed which validates this particular form of stochastic resonance, showing that the response can indeed be amplified when the frequency of the weak periodic modulating excitation fulfills the correct occurrence condition. The experimental results indicate that the available power generated under this condition of stochastic resonance is noticeably higher than the power that can be collected under other harvesting conditions.

Zheng, Rencheng; Nakano, Kimihiko; Hu, Honggang; Su, Dongxu; Cartmell, Matthew P.

2014-06-01

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

NASA Astrophysics Data System (ADS)

This manuscript is motivated by research that shows the shear, d15, mode energy harvesters offer significant improvement in power generation over the traditional normal, d31, mode based harvesters. The premise behind this study is to examine the effect of expanding the design domain of PZT based energy harvesters by considering an arbitrary poling angle. In the first part of the manuscript, we derive the equation of motions of a harvester based on Timoshenko beam theory in an unimorph configuration. The resulting equations are solved using a Rayleigh Ritz analysis. The electric displacement depends on both the normal and shear strain. Thus the proposed device operates using a combination of shear and normal modes to extract power. The extent to which each mode is used depends on the polarization orientation. We examine the effect of poling on the fundamental short and open circuit frequencies. Next, the poling angle is examined over a range to determine the effect on the power harvested at the fundamental modal frequencies of the system. The study demonstrates that an arbitrary poled piezoelectric increases the power that the harvester produces over traditionally poled devices; however, the performance is highly dependent on the geometry.

Gibert, James M.

2014-04-01

145

Electromechanical and statistical modeling of turbulence-induced vibration for energy harvesting

NASA Astrophysics Data System (ADS)

Preliminary experimental studies have shown that piezoelectric structures excited by turbulent flow can produce significant amounts of useful power. The research presented in this paper could benefit applications such as powering self-sustained sensor networks in small rivers or air flow environments where turbulent fluid flow is a primary source of ambient energy. A novel prototype called piezoelectric grass was designed to be a robust solution for harvesting energy in turbulent fluid flow environments. In this paper, the authors present an experimentally validated theoretical analysis of the piezoelectric grass harvester modeled as a single unimorph cantilever beam exposed to turbulent cross-flow. Lastly, a brief parameter optimization study will be presented. This study will demonstrate how the unimorph harvester design could be modified to achieve maximum power output in a given turbulent fluid flow condition.

Hobeck, Jared D.; Inman, Daniel J.

2013-04-01

146

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

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

147

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

148

Autonomous wideband mechanical energy harvester

The aim of this work is to demonstrate, by theory and experiment, the feasibility of a mechanical energy harvester able to operate with a high efficiency over a wide vibration frequency band. Herein this work we propose a new method for adjusting the resonant frequency of a mechanical harvester, based on piezoelectric material. The idea is to use the dependence

B. Ahmed Seddik; G. Despesse; E. Defay

2012-01-01

149

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

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

M. Amin Karami; Daniel J. Inman

2011-01-01

150

NASA Astrophysics Data System (ADS)

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 of about 4.800 mm × 0.400 mm × 0.036 mm and an integrated Si mass dimension of about 1.360 mm × 0.940 mm × 0.456 mm produced 160 mVpk, 2.15 ?W or 3272 ?W cm-3 with an optimal resistive load of 6 k? from 2g (g = 9.81 m s-2) acceleration at its resonant frequency of 461.15 Hz. This device was compared with other demonstrated MEMS power generators.

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

2008-05-01

151

NASA Astrophysics Data System (ADS)

Piezoelectric vibration energy harvester arrays using Pb(Zr,Ti)O3 thin films on 200 mm SOI wafers were fabricated. In-plane distribution of influence of bipolar pulse poling technique on direct current (DC) power output from the harvesters was investigated. The results indicate that combination poling treatment of DC and bipolar pulse poling increases a piezoelectric property and reduces a dielectric constant. It means that this poling technique improves the figure of merit of sensors and harvesters. Maximum DC power from a harvester treated by DC poling after bipolar pulse poling is about five times larger than a one treated by DC poling only.

Moriwaki, N.; Kobayashi, T.; Suzuki, Y.; Makimoto, N.; Fujimoto, K.; Suzuki, K.; Itoh, T.; Maeda, R.

2013-12-01

152

Vibration shape effects on the power output in piezoelectric vibro-impact energy harvesters

NASA Astrophysics Data System (ADS)

Vibro-Impcact harvesting devices are one concept to increase the bandwidth of resonant operated piezoelectric vibration generators. The fundamental setup is a piezoelectric bending element, where the deflection is limited by two stoppers. After starting the system in resonance operation the bandwidth increases towards higher frequencies as soon the deflection reach the stopper. If the stoppers are rigid, the frequency response gives constant amplitude for increasing frequencies, as long the system is treated as ideal one-DOF system with symmetric stoppers. In consequence, the bandwidth is theoretically unlimited large. However, such a system also has two major drawbacks, firstly the complicated startup mechanism and secondly the tendency to drop from the high constant branch in the frequency response on the much smaller linear branch if the system is disturbed. Nevertheless, the system has its application wherever the startup problem can be solved. Most modeling approaches utilize modal one-DOF models to describe the systems behavior and do not tread the higher harmonics of the beam. This work investigates the effects of the stoppers on the vibration shape of the piezoelectric beam, wherefore a finite element model is used. The used elements are one-dimensional two node elements based on the Timoshenko-beam theory. The finite element code is implemented in Matlab. The model is calculated utilizing time step integration for simulation, to reduce the computation time an auto-resonant calculation method is implemented. A control loop including positive feedback and saturation is used to create a self-excited system. Therefore, the system is always operated in resonance (on the backbone curve) and the frequency is a direct result of the computation. In this case tip velocity is used as feedback. This technique allows effective parametric studies. Investigated parameters include gap, excitation amplitude, tip mass as well as the stiffness of the stopper. The stress and strain distribution as well as the generated electrical power is analyzed with respect to the proper operation range.

Twiefel, Jens

2013-04-01

153

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

154

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

155

Efficient Energy Harvesting from Irregular Mechanical Vibrations by Active Motion Control

A vibration-driven micropower generator with a high-Q mechanical resonator efficiently works under single-frequency vibration. However, the associated narrow operation frequency bandwidth tightly limits the power output under commonly observed wideband ambient vibrations. In this paper, we present a power-generation scheme in which the motion of an internal mass element is actively controlled. The control is such that the vibrating environment

Hiroshi Okamoto; Teppei Onuki; Sumito Nagasawa; Hiroki Kuwano

2009-01-01

156

We fabricated dual-beam cantilevers on the microelectromechanical system (MEMS) scale with an integrated Si proof mass. A Pb(Zr,Ti)O3 (PZT) cantilever was designed as a mechanical vibration energy-harvesting system for low power applications. The resonant frequency of the multilayer composition cantilevers were simulated using the finite element method (FEM) with parametric analysis carried out in the design process. According to simulations, the resonant frequency, voltage, and average power of a dual-beam cantilever was 69.1 Hz, 113.9 mV, and 0.303 microW, respectively, at optimal resistance and 0.5 g (gravitational acceleration, m/s2). Based on these data, we subsequently fabricated cantilever devices using dual-beam cantilevers. The harvested power density of the dual-beam cantilever compared favorably with the simulation. Experiments revealed the resonant frequency, voltage, and average power density to be 78.7 Hz, 118.5 mV, and 0.34 microW, respectively. The error between the measured and simulated results was about 10%. The maximum average power and power density of the fabricated dual-beam cantilever at 1 g were 0.803 microW and 1322.80 microW cm(-3), respectively. Furthermore, the possibility of a MEMS-scale power source for energy conversion experiments was also tested. PMID:24266167

Kim, Moonkeun; Lee, Sang-Kyun; Yang, Yil Suk; Jeong, Jaehwa; Min, Nam Ki; Kwon, Kwang-Ho

2013-12-01

157

Design and fabrication of bimorph transducer for optimal vibration energy harvesting.

High energy density piezoelectric composition corresponding to 0.9Pb(Zr0.56Ti0.44)O3–0.1Pb[(Zn0.8/3Ni0.2/3) Nb2/3]O3 + 2 mol% MnO2 (PZTZNN) and 0.8[Pb(Zr0.52Ti0.48) O3]-0.2[Pb(Zn1/3Nb2/3)O3] (PZTPZN) were synthesized by conventional ceramic processing technique using three different sintering profiles. Plates of the sintered samples were used to fabricate the piezoelectric bimorphs with optimized dimensions to exhibit resonance in the loaded condition in the range of ~200 Hz. An analytical model for energy harvesting from bimorph transducer was developed which was confirmed by experimental measurements. The results of this study clearly 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. PMID:20941885

Bedekar, Vishwas; Oliver, Josiah; Priya, Shashank

2010-07-01

158

NASA Astrophysics Data System (ADS)

In this paper, we propose a passive gap-spacing control method in order to avoid stiction between top and bottom structures in in-plane sensor/actuator/generator applications. A patterned electret using a high-performance perfluoro polymer material is employed to induce a repulsive electrostatic force. An out-of-plane repulsive force is successfully demonstrated with our early prototype, in both air and liquid. By using the present electret-based levitation method to keep the air gap, a MEMS electret generator has been developed for energy-harvesting applications. A dual-phase electrode arrangement is adopted in order to reduce the horizontal electrostatic damping force. With the present prototype, about 0.5 µW is obtained for both phases of the generator, resulting in a total power output of 1.0 µW at an acceleration of 2 g with 63 Hz. With our electromechanical model of the generator, we have confirmed that the model can mimic the response of the generator prototype.

Suzuki, Yuji; Miki, Daigo; Edamoto, Masato; Honzumi, Makoto

2010-10-01

159

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

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

160

Low-frequency two-dimensional resonators for vibrational micro energy harvesting

NASA Astrophysics Data System (ADS)

The fabrication, characterization and theoretical analysis of a novel two-dimensional silicon resonator with threefold rotational symmetry are described. The resonator consists of a 4 mm wide disk-shaped seismic mass having the full-wafer thickness of 525 µm and suspended by a system of concentric circular springs. The device is structured using two-sided deep reactive-ion etching of silicon. With its current spring thickness and height, the device has two closely spaced resonance frequencies at 370.5 and 373.9 Hz and a quality factor of 1800 at ambient pressure. The spring height and thus the resonance frequency of the device are easily tuned by simple adjustment of a single etch duration in the entire fabrication process. The dynamic response of the structure is modeled under the two assumptions that silicon is elastically (i) isotropic and (ii) anisotropic. In comparison with the isotropic model, the elastic anisotropy leads to a predicted mode splitting by 6.2 Hz, with oscillation directions aligned with the cubic crystal axes. Even small geometrical imperfections are found to significantly rotate the eigenmodes and to further modulate their frequency splitting. Experimental and numerical results corroborate these conclusions. Overall the present resonator design has the potential for a higher energy harvesting efficiency than a combination of two separate one-dimensional oscillators.

Bartsch, U.; Gaspar, J.; Paul, O.

2010-03-01

161

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

162

Energy flow in piezoelectric energy harvesting systems

NASA Astrophysics Data System (ADS)

In the research of piezoelectric energy harvesting (PEH), the previous foci were mostly on the amount of energy that can be harvested from the ambient vibration sources. Other portions of energy, e.g., the energy dissipated during the harvesting process, were seldom considered in PEH systems. Yet, the ignorance on these energies might cause some misunderstanding in the studies of energy harvesting. This paper sets up an energy flow based framework for the analysis of PEH systems. An energy flow chart is introduced to comprehensively illustrate the energy paths within the PEH system. Taking the interface circuits of standard energy harvesting (SEH) and synchronized switch harvesting on inductor (SSHI) as examples, different branches of energy flow in the PEH systems are quantitatively investigated. In the previous literature, only the harvested energy was emphasized as a function of the rectified voltage or its corresponding DC load resistance. To be more general, we show that both the harvesting energy and dissipated energy change with the rectified voltage; in addition, these two portions of energy also depend on the ratio between the rectifier voltage drop and the open circuit voltage. Three experiments are carried out with an SSHI device to measure its performances on energy harvesting, energy dissipation, and structural damping. The experimental results show good agreement with theoretical analysis. The functional relations among these branches of energy flow are found.

Liang, Junrui; Liao, Wei-Hsin

2011-01-01

163

A piezoelectric MEMS energy harvester (EH) with low resonant frequency and wide operation bandwidth was de- signed, microfabricated, and characterized. The MEMS piezo- electric energy harvesting cantilever consists of a silicon beam integrated with piezoelectric thin film (PZT) elements parallel- arranged on top and a silicon proof mass resulting in a low resonant frequency of 36 Hz. The whole chip

Huicong Liu; Cho Jui Tay; Chenggen Quan; Takeshi Kobayashi; Chengkuo Lee

2011-01-01

164

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

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

165

NASA Astrophysics Data System (ADS)

In this paper, an innovative strategy for improving the performance of a recently developed rotational energy harvester is proposed. Its performance can be considerably enhanced by replacing the electromagnetic induction part, consisting of moving permanent magnets and a fixed solenoid coil, with a moving mass and a rotational generator (i.e., an electric motor). The proposed system is easily tuned to the natural frequency of a target structure using the position change of a proof mass. Owing to the high efficiency of the rotational generator, the device can more effectively harness electrical energy from the wind-induced vibration of a stay cable. Also, this new configuration makes the device more compact and geometrically tunable. In order to validate the effectiveness of the new configuration, a series of laboratory and field tests are carried out with the prototype of the proposed device, which is designed and fabricated based on the dynamic characteristics of the vibration of a stay cable installed in an in-service cable-stayed bridge. From the field test, it is observed that the normalized output power of the proposed system is 35.67 mW (m s-2)-2, while that of the original device is just 5.47 mW (m s-2)-2. These results show that the proposed device generates much more electrical energy than the original device. Moreover, it is verified that the proposed device can generate sufficient electricity to power a wireless sensor node placed on a cable under gentle-moderate wind conditions.

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

2013-07-01

166

Multi-mechanism vibration harvester combining inductive and piezoelectric mechanisms

NASA Astrophysics Data System (ADS)

With increasing demand for wireless sensor nodes in automobile, aircraft and rail applications, the need for energy harvesters has been growing. In these applications, energy harvesters provide a more robust and inexpensive power solution than batteries. In order to enhance the power density of existing energy harvesters, a variety of multimodal energy harvesting techniques have been proposed. Multi-modal energy harvesters can be categorized as: (i) Multi-Source Energy Harvester (MSEH), (ii) Multi-Mechanism Energy Harvester (MMEH), and (iii) Single Source Multi-Mode Energy Harvester (S2M2EH). In this study, we focus on developing MMEH which combines the inductive and piezoelectric mechanisms. The multi-mechanism harvester was modeled using FEM techniques and theoretically analyzed to optimize the performance and reduce the overall shape and size similar to that of AA battery. The theoretical model combining analytical and FEM modeling techniques provides the system dynamics and output power for specific generator and cymbal geometry at various source conditions. In the proposed design, a cylindrical tube contains a magnetic levitation cavity where a center magnet oscillates through a copper coil. Piezoelectric cymbal transducers were mounted on the top and bottom sections of the cylindrical shell. In response to the external vibrations, electrical energy was harvested from the relative motion between magnet and coil through Faraday's effect and from the piezoelectric material through the direct piezoelectric effect. Experimental results validate the predictions from theoretical model and show the promise of multimodal harvester for powering wireless sensor nodes in automobile, aircraft, and rail applications.

Marin, Anthony; Priya, Shashank

2012-03-01

167

NASA Astrophysics Data System (ADS)

A multiphysics model of a hybrid piezoelectric–electromagnetic vibration energy harvester (VEH), including the main sources of nonlinearities, is developed. The continuum problem is derived on the basis of the extended Hamilton principle, and the modal Galerkin decomposition method is used in order to obtain a reduced-order model consisting of a nonlinear Duffing equation of motion coupled with two transduction equations. The resulting system is solved analytically using the method of multiple time scales and numerically by means of the harmonic balance method coupled with the asymptotic numerical continuation technique. Closed-form expressions for the moving magnet critical amplitude and the critical load resistance are provided in order to allow evaluation of the linear dynamic range of the proposed device. Several numerical simulations have been performed to highlight the performance of the hybrid VEH. In particular, the power density and the frequency bandwidth can be boosted, by up to 60% and 29% respectively, compared to those for a VEH with pure magnetic levitation thanks to the nonlinear elastic guidance. Moreover, the hybrid transduction permits enhancement of the power density by up to 84%.

Mahmoudi, S.; Kacem, N.; Bouhaddi, N.

2014-07-01

168

Nanocrystalline ribbons for energy harvesting applications

NASA Astrophysics Data System (ADS)

An energy harvesting device based on nanocrystalline ribbons, able to convert mechanical vibrations to electrical energy, is presented. Such an energy harvesting device having embedded wireless microsensors can provide continuous monitoring of machines or infrastructure health without using service personnel in different areas with high risks. A multilayer core based on magnetic nanocrystalline ribbons was implemented to build the coil for an electromagnetic energy harvesting device with superior characteristics (voltage and power) compared to piezoelectric or pure magnetostrictive devices. Two different configurations were realized and tested for the energy harvester: vibrating core and vibrating magnets. The highest power density achieved for our harvesters using nanocrystalline ribbons is 45 mW/cm3 at 1 g (resonant frequency 47 Hz) and seems to be among the highest reported in literature.

Chiriac, H.; Å¢ibu, M.; Lupu, N.; Skorvanek, I.; Óvári, T.-A.

2014-05-01

169

Fabrication and characterization of a wideband MEMS energy harvester utilizing nonlinear springs

This paper presents the fabrication, characterization and modeling of a wideband MEMS electrostatic energy harvester utilizing nonlinear springs. The experimental results show that the vibration energy harvester displays a strong softening spring effect. For narrow band vibration, the energy harvester exhibits a widening bandwidth during frequency down-sweeps. For increasing levels of broadband random noise vibration, the energy harvester displays a

D. S. Nguyen; E. Halvorsen; G. U. Jensen; A. Vogl

2010-01-01

170

A multiaxial piezoelectric energy harvester

NASA Astrophysics Data System (ADS)

An important limitation in the classical energy harvesters based on cantilever beam structure is its monodirectional sensibility. The external excitation must generate an orthogonal acceleration from the beam plane to induced flexural deformation. If the direction of the excitation deviates from this privileged direction, the harvester output power is drastically reduced. This point is obviously very restrictive in the case of an arbitrary excitation direction induced for example by human body movements or vehicles vibrations. In order to overcome this issue of the conventional resonant cantilever configuration with seismic mass, a multidirectional harvester is introduced here by the authors. The multidirectional ability relies on the exploitation of 3 degenerate structural vibration modes where each of them is induced by the corresponding component of the acceleration vector. This specific structure has been already used for 3 axis accelerometers but the approach is here totally revisited because the final functional goal is different. This paper presents the principle and the design considerations of such multidirectional piezoelectric energy harvester. A finite element model has been used for the harvester optimisation. It has been shown that the seismic mass is a relevant parameter for the modes tuning because the resonant frequency of the 1st exploited flexural mode directly depends on the mass whereas the resonance frequency of the 2nd flexural mode depends on its moment of inertia. A simplified centimetric prototype limited to a two orthogonal direction sensibility has permitted to valid the theoretical approach.

Mousselmal, H. D.; Cottinet, P. J.; Quiquerez, L.; Remaki, B.; Petit, L.

2013-04-01

171

DSPs for energy harvesting sensors: applications and architectures

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

172

Synchronized charge extraction for aeroelastic energy harvesting

NASA Astrophysics Data System (ADS)

Aeroelastic instabilities have been frequently exploited for energy harvesting purpose to power standalone electronic systems, such as wireless sensors. Meanwhile, various energy harvesting interface circuits, such as synchronized charge extraction (SCE) and synchronized switching harvesting on inductor (SSHI), have been widely pursued in the literature for efficiency enhancement of energy harvesting from existing base vibrations. These interfaces, however, have not been applied for aeroelastic energy harvesting. This paper investigates the feasibility of the SCE interface in galloping-based piezoelectric energy harvesting, with a focus on its benefit for performance improvement and influence on the galloping dynamics in different electromechanical coupling regimes. A galloping-based piezoelectric energy harvester (GPEH) is prototyped with an aluminum cantilever bonded with a piezoelectric sheet. Wind tunnel test is conducted with a simple electrical interface composed of a resistive load. Circuit simulation is performed with equivalent circuit representation of the GPEH system and confirmed by experimental results. Consequently, a self-powered SCE interface is implemented with the capability of self peak-detecting and switching. Circuit simulation for various electromechanical coupling cases shows that the harvested power with SCE interface for GPEH is independent of the electrical load, similar to that for a vibration-based piezoelectric energy harvester (VPEH). The SCE interface outperforms the standard interface if the electromechanical coupling is weak, and requires much less piezoelectric material to achieve the maximum power output. Moreover, influence of electromechanical coupling on the dynamics of GPEH with SCE is found sensitive to the wind speed.

Zhao, Liya; Tang, Lihua; Wu, Hao; Yang, Yaowen

2014-03-01

173

Fabrication and characterization of a wideband MEMS energy harvester utilizing nonlinear springs

NASA Astrophysics Data System (ADS)

This paper presents the fabrication, characterization and modeling of a wideband MEMS electrostatic energy harvester utilizing nonlinear springs. The experimental results show that the vibration energy harvester displays a strong softening spring effect. For narrow band vibration, the energy harvester exhibits a widening bandwidth during frequency down-sweeps. For increasing levels of broadband random noise vibration, the energy harvester displays a broadening bandwidth response. Furthermore, the vibration energy harvester with softening springs not only increases the bandwidth, but also harvests more output power than a linear energy harvester at a sufficient level of broadband random vibration. At a broadband random vibration of 7.0 × 10-4 g2 Hz-1, we found that the bandwidth increases by more than 13 times and the average harvesting output power increases by 68% compared to that of a linear vibration energy harvester. Numerical analysis confirmed that the softening springs are responsible for the band broadening.

Nguyen, D. S.; Halvorsen, E.; Jensen, G. U.; Vogl, A.

2010-12-01

174

NASA Astrophysics Data System (ADS)

In this paper, we investigate underwater energy harvesting of a parallel array of nominally identical ionic polymer metal composites (IPMCs) subjected to low frequency base excitation in water. The IPMCs are connected in parallel and shunted with a varying resistor. We model the IPMCs as slender beams with uniform cross section undergoing small oscillations in an otherwise quiescent viscous fluid. We utilize a boundary element approach to compute the hydrodynamic loading on each structure, which is due to the oscillations of the whole array. Leveraging recent findings on sensing in ionic polymer metal composites, we propose a coupled electromechanical model for predicting energy harvesting as a function of the IPMCs’ impedance and the base excitation. To validate our theoretical predictions, we perform experiments on an in-house-fabricated array of five centimeter-size composites, which we characterize on a dedicated test rig. We experimentally determine the power harvested by varying the excitation frequency in the broad range 2-35 Hz and the shunting resistance from 1 to 1000 ?.

Cellini, Filippo; Intartaglia, Carmela; Soria, Leonardo; Porfiri, Maurizio

2014-04-01

175

PIEZOELECTRIC MICRO POWER GENERATOR FOR ENERGY HARVESTING

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

176

The objective of this paper is to present pertinent cost and productivity data for several wood harvesting operations. These operations were not all conducted to provide wood fuel, but the information is still of value to those considering the harvest of wood for energy. The case studies are based on the following harvesting operations: Two mechanized thinning operations in pole-sized hardwoods. One hardwood land-clearing operation (for agricultural land). One hardwood land-clearing operation (for site conversion). One relogging operation of hardwood tops and limbs resulting from a saw log harvest. All of the studies were conducted between 1974 and 1978. Information on the costs and productivity of commercial logging equipment is included.

Arola, R.A.; Miyata, E.S.

1981-01-01

177

The physical acoustics of energy harvesting

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

178

NASA Astrophysics Data System (ADS)

A novel three-dimensional (3D) electret-based micro power generator with multiple vibration modes has been developed, which is capable of converting low-level ambient kinetic energy to electrical energy. The device is based on a rotational symmetrical resonator which consists of a movable disc-shaped seismic mass suspended by three sets of spiral springs. Experimental analysis shows that the proposed generator operates at an out-of-plane direction at mode I of 66 Hz and two in-plane directions at mode II of 75 Hz and mode III of 78.5 Hz with a phase difference of about 90°. A corona localized charging method is also proposed that employs a shadow mask and multiple discharge needles for the production of micro-sized electret array. From tests conducted at an acceleration of 0.05 g, the prototype can generate a maximum power of 4.8 nW, 0.67 nW and 1.2 nW at vibration modes of I, II and III, respectively. These values correspond to the normalized power densities of 16 µW cm?3 g?2, 2.2 µW cm?3 g?2 and 4 µW cm?3 g?2, respectively. The results show that the generator can potentially offer an intriguing alternative for scavenging low-level ambient energy from 3D vibration sources.

Tao, Kai; Liu, Shuwei; Woh Lye, Sun; Miao, Jianmin; Hu, Xiao

2014-06-01

179

Piezoelectric monolayers as nonlinear energy harvesters

NASA Astrophysics Data System (ADS)

We study the dynamics of h-BN monolayers by first performing ab-initio calculations of the deformation potential energy and then solving numerically a Langevine-type equation to explore their use in nonlinear vibration energy harvesting devices. An applied compressive strain is used to drive the system into a nonlinear bistable regime, where quasi-harmonic vibrations are combined with low-frequency swings between the minima of a double-well potential. Due to its intrinsic piezoelectric response, the nonlinear mechanical harvester naturally provides an electrical power that is readily available or can be stored by simply contacting the monolayer at its ends. Engineering the induced nonlinearity, a 20 nm^{2} device is predicted to harvest an electrical power of up to 0.18 pW for a noisy vibration of 5 pN.

López-Suárez, Miquel; Pruneda, Miguel; Abadal, Gabriel; Rurali, Riccardo

2014-05-01

180

Piezoelectric monolayers as nonlinear energy harvesters.

We study the dynamics of h-BN monolayers by first performing ab-initio calculations of the deformation potential energy and then solving numerically a Langevine-type equation to explore their use in nonlinear vibration energy harvesting devices. An applied compressive strain is used to drive the system into a nonlinear bistable regime, where quasi-harmonic vibrations are combined with low-frequency swings between the minima of a double-well potential. Due to its intrinsic piezoelectric response, the nonlinear mechanical harvester naturally provides an electrical power that is readily available or can be stored by simply contacting the monolayer at its ends. Engineering the induced nonlinearity, a 20 nm[Formula: see text] device is predicted to harvest an electrical power of up to 0.18 pW for a noisy vibration of 5 pN. PMID:24722065

López-Suárez, Miquel; Pruneda, Miguel; Abadal, Gabriel; Rurali, Riccardo

2014-05-01

181

Motorcycle waste heat energy harvesting

NASA Astrophysics Data System (ADS)

Environmental concerns coupled with the depletion of fuel sources has led to research on ethanol, fuel cells, and even generating electricity from vibrations. Much of the research in these areas is stalling due to expensive or environmentally contaminating processes, however recent breakthroughs in materials and production has created a surge in research on waste heat energy harvesting devices. The thermoelectric generators (TEGs) used in waste heat energy harvesting are governed by the Thermoelectric, or Seebeck, effect, generating electricity from a temperature gradient. Some research to date has featured platforms such as heavy duty diesel trucks, model airplanes, and automobiles, attempting to either eliminate heavy batteries or the alternator. A motorcycle is another platform that possesses some very promising characteristics for waste heat energy harvesting, mainly because the exhaust pipes are exposed to significant amounts of air flow. A 1995 Kawasaki Ninja 250R was used for these trials. The module used in these experiments, the Melcor HT3-12-30, produced an average of 0.4694 W from an average temperature gradient of 48.73 °C. The mathematical model created from the Thermoelectric effect equation and the mean Seebeck coefficient displayed by the module produced an average error from the experimental data of 1.75%. Although the module proved insufficient to practically eliminate the alternator on a standard motorcycle, the temperature data gathered as well as the examination of a simple, yet accurate, model represent significant steps in the process of creating a TEG capable of doing so.

Schlichting, Alexander D.; Anton, Steven R.; Inman, Daniel J.

2008-04-01

182

This paper presents a new technique for optimized energy harvesting using piezoelectric microgenerators called double synchronized switch harvesting (DSSH). This technique consists of a nonlinear treatment of the output voltage of the piezoelectric element. It also integrates an intermediate switching stage that ensures an optimal harvested power whatever the load connected to the microgenerator. Theoretical developments are presented considering either constant vibration magnitude, constant driving force, or independent extraction. Then experimental measurements are carried out to validate the theoretical predictions. This technique exhibits a constant output power for a wide range of load connected to the microgenerator. In addition, the extracted power obtained using such a technique allows a gain up to 500% in terms of maximal power output compared with the standard energy harvesting method. It is also shown that such a technique allows a fine-tuning of the trade-off between vibration damping and energy harvesting. PMID:18986861

Lallart, Mickaël; Garbuio, Lauric; Petit, Lionel; Richard, Claude; Guyomar, Daniel

2008-10-01

183

Over the years, there has been a growing interest in the field of power harvesting technologies for low-power electronic devices, such as wireless sensor networks and biomedical sensor applications. Of all possible energy sources, the mechanical vibrations have been considered a potential choice for power harvesting in a wide variety of applications. This paper presents the development of a piezoelectric

Bor-Shun Lee; Jyun-Jhang He; Wen-Jong Wu; Wen-Pin Shih

2006-01-01

184

Algae Harvest Energy Conversion

\\u000a Algae harvest energy conversion to biofuel technology is a promising alternative to fossil fuel that has inherent pollution\\u000a attachment. With present resources available for the microalgae mass production and hence, high oil yield, microalgal can\\u000a sufficiently be a new source of renewable energy to replace the fossil fuels. In this chapter, algae description, composition,\\u000a cultivation, its conversion to biofuel, and

Yung-Tse Hung; O. Sarafadeen Amuda; A. Olanrewaju Alade; I. Adekunle Amoo; Stephen Tiong-Lee Tay; Kathleen Hung Li

185

Energy harvesting through wind excitation of a piezoelectric flag-like harvester

NASA Astrophysics Data System (ADS)

This study seeks to propose a novel approach to wind-based piezoelectric energy harvesting. A brief literature review of energy harvesting followed by a discussion of piezoelectric system dynamics is offered. Biomedical applications for piezoelectric energy harvesting are then presented offering a segue into fluid based energy harvesting. Fluid based energy harvesting is a relatively young subfield within piezoelectric energy harvesting, but it is increasingly pursued due to the ubiquitous nature of the excitation source as well as the strong correlation with other types of excitation. Vortex-induced vibrations (VIV), as well as vibrations induced by bluff bodies, and the effect of their shape on potential gains have been investigated. The interactions of VIVs on a flag-like membrane form the foundation for the piezoelectric energy harvester in this study. Polyvinylidene fluoride (PVDF) piezoelectric energy harvesters are chosen due to their desirable flexibility. Modeling of flag-like systems is review followed by system modeling of a PVDF piezoelectric flag. Numerical and experimental results from the PVDF flag-like piezoelectric energy harvester are generated and compared. A maximum power output of 1.5 mW is achieved with the flag-like system which is competitive when compared to power output and energy density levels of other studies. The power output of this system provides concrete evidence for the effective use of not only this type of energy harvester system model but also for the use of PVDFs in wind-based applications.

Truitt, Andrew

186

Shape improvement for piezoelectric energy harvesting applications

We aim at using variable shape cantilever beam to improve the efficiency of energy harvesting from ambient vibration in wireless grid sensor applications. The cantilever beam is composed of an active layer composed of a piezoelectric material and a metallic layer (unimorph design). A tip mass attached to the free end of the cantilever beam is added to increase the

Sameh Ben Ayed; Fehmi Najar; Abdessattar Abdelkefi

2009-01-01

187

A broadband electromagnetic energy harvester with a coupled bistable structure

NASA Astrophysics Data System (ADS)

This paper investigates a broadband electromagnetic energy harvester with a coupled bistable structure. Both analytical model and experimental results showed that the coupled bistable structure requires lower excitation force to trigger bistable operation than conventional bistable structures. A compact electromagnetic vibration energy harvester with a coupled bistable structure was implemented and tested. It was excited under white noise vibrations. Experimental results showed that the coupled bistable energy harvester can achieve bistable operation with lower excitation amplitude and generate more output power than both conventional bistable and linear energy harvesters under white noise excitation.

Zhu, D.; Beeby, S. P.

2013-12-01

188

Piezoelectric Energy Harvesting Solutions

This paper reviews the state of the art in piezoelectric energy harvesting. It presents the basics of piezoelectricity and discusses materials choice. The work places emphasis on material operating modes and device configurations, from resonant to non-resonant devices and also to rotational solutions. The reviewed literature is compared based on power density and bandwidth. Lastly, the question of power conversion is addressed by reviewing various circuit solutions.

Calio, Renato; Rongala, Udaya Bhaskar; Camboni, Domenico; Milazzo, Mario; Stefanini, Cesare; de Petris, Gianluca; Oddo, Calogero Maria

2014-01-01

189

Vibration and noise characteristics of flap type olive harvesters.

The object of this study was to measure and evaluate the vibration and noise characteristics of five flap type portable harvesters using for olive harvesting and their effect on operator health during harvesting time. The vibration and sound pressure levels of different harvesters were measured at both idling and full load conditions. The vibration values of harvesters were measured and analyzed for both right and left hands and the sound pressure level was measured at ear level of the operator. The vibration total value was expressed as the root-mean-squares (rms) of three component values. The results indicated that in 10% of the exposed population traumatic vasospastic disease (TVD) appeared after 0.7-7.1 years for the left hand, 1.0-4.7 years for the right hand of the operator in continuous use of these harvesters, under usual working conditions. The sound pressure values at operator's ear level of harvesters were found below risk levels when compared with ILO standards. PMID:20869693

Cakmak, Bülent; Saraço?lu, Türker; Alayunt, Fazilet N; Ozarslan, Cengiz

2011-03-01

190

Piezoelectric Energy Harvesting and Dissipation on Structural Damping

This article aims to provide a comparative study on the functions of piezoelectric energy harvesting, dissipation, and their effects on the structural damping of vibrating structures. Energy flow in piezoelectric devices is discussed. Detailed modeling of piezoelectric materials and devices are provided to serve as a common base for both analyses of energy harvesting and dissipation. Based on these foundations,

J. R. Liang; W. H. Liao

2009-01-01

191

Flexible electret energy harvesters with parylene electret on PDMS substrates

NASA Astrophysics Data System (ADS)

Currently, most vibrational energy harvesters have rigid and resonant structures to harvest energy from periodic motions in specific directions. However, in some situations the motion is random and aperiodic; or the targeted energy source is the strain energy in deformation, rather than the kinetic energy in vibration. Therefore we propose and demonstrate a PDMS-based flexible energy harvester with parylene-C electret that can be attached to any deformable surfaces to harvest the stain energy caused by external deformation. The proposed flexible harvester was fabricated and characterized. The measured power at 20 Hz is 0.18 ?W and 82 nW in the compression and bending modes, respectively. Such a harvester has the potential for wearable and implantable electronics applications.

Chiu, Yi; Wu, Shih-Hsien

2013-12-01

192

Development of energy harvesting device using piezoelectric material

Using piezoelectric elements to harvest energy from ambient vibration and human motion has been of great interest recently. This study quantifies the amount of energy generated by piezoelectric device from vibration environment and human motion. Nickel metal hydride rechargeable battery has been used to store the energy generated. Throughout the experiment, the discharged 40mAh rechargeable battery can be charged to

Robiah Ahmad; Mohd Hanifah Hashim

2011-01-01

193

Final Report: Energy Harvesting from Rail Track for Transportation Safety and Monitoring.

National Technical Information Service (NTIS)

An efficient electromagnetic energy harvester featured with mechanical motion rectifier (MMR) is designed to recover energy from the vibration-like railroad track deflections induced by passing trains. Comparing to typical existing vibration energy harves...

J. Wang L. Zuo T. Lin

2014-01-01

194

An electromechanical finite element model for piezoelectric energy harvester plates

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

Carlos De Marqui Junior; Alper Erturk; Daniel J. Inman

2009-01-01

195

A new piezoelectric energy harvesting design concept: multimodal energy harvesting skin.

This paper presents an advanced design concept for a piezoelectric energy harvesting (EH), referred to as multimodal EH skin. This EH design facilitates the use of multimodal vibration and enhances power harvesting efficiency. The multimodal EH skin is an extension of our previous work, EH skin, which was an innovative design paradigm for a piezoelectric energy harvester: a vibrating skin structure and an additional thin piezoelectric layer in one device. A computational (finite element) model of the multilayered assembly - the vibrating skin structure and piezoelectric layer - is constructed and the optimal topology and/or shape of the piezoelectric layer is found for maximum power generation from multiple vibration modes. A design rationale for the multimodal EH skin was proposed: designing a piezoelectric material distribution and external resistors. In the material design step, the piezoelectric material is segmented by inflection lines from multiple vibration modes of interests to minimize voltage cancellation. The inflection lines are detected using the voltage phase. In the external resistor design step, the resistor values are found for each segment to maximize power output. The presented design concept, which can be applied to any engineering system with multimodal harmonic-vibrating skins, was applied to two case studies: an aircraft skin and a power transformer panel. The excellent performance of multimodal EH skin was demonstrated, showing larger power generation than EH skin without segmentation or unimodal EH skin. PMID:21429855

Lee, Soobum; Youn, Byeng D

2011-03-01

196

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

197

Energy harvesting for self-powered aerostructure actuation

NASA Astrophysics Data System (ADS)

This paper proposes and experimentally investigates applying piezoelectric energy harvesting devices driven by flow induced vibrations to create self-powered actuation of aerostructure surfaces such as tabs, flaps, spoilers, or morphing devices. Recently, we have investigated flow-induced vibrations and limit cycle oscillations due to aeroelastic flutter phenomena in piezoelectric structures as a mechanism to harvest energy from an ambient fluid flow. We will describe how our experimental investigations in a wind tunnel have demonstrated that this harvested energy can be stored and used on-demand to actuate a control surface such as a trailing edge flap in the airflow. This actuated control surface could take the form of a separate and discrete actuated flap, or could constitute rotating or deflecting the oscillating energy harvester itself to produce a non-zero mean angle of attack. Such a rotation of the energy harvester and the associated change in aerodynamic force is shown to influence the operating wind speed range of the device, its limit cycle oscillation (LCO) amplitude, and its harvested power output; hence creating a coupling between the device's performance as an energy harvester and as a control surface. Finally, the induced changes in the lift, pitching moment, and drag acting on a wing model are quantified and compared for a control surface equipped with an oscillating energy harvester and a traditional, static control surface of the same geometry. The results show that when operated in small amplitude LCO the energy harvester adds negligible aerodynamic drag.

Bryant, Matthew; Pizzonia, Matthew; Mehallow, Michael; Garcia, Ephrahim

2014-04-01

198

Adaptive piezoelectric energy harvesting circuit for wireless remote power supply

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

199

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

200

Power harvesters that extract energy from vibrating systems via piezoelectric transduction show strong potential for powering smart wireless sensor devices in applications of health condition monitoring of rotating machinery and structures. This paper presents an analytical method for modelling an electromechanical piezoelectric bimorph beam with tip mass under two input base transverse and longitudinal excitations. The Euler–Bernoulli beam equations were

M. F. Lumentut; I. M. Howard

201

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

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

202

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

203

Energy Harvesting - A Systems Perspective

Deployment of sensing devices in remote areas makes battery replacement virtually impossible, so harvesting available energy for replenishment of the supply is essential. The energy available is very small, therefore ultra low power design for both computation and communication devices is required. In the paper, we will discuss the need for a system- level approach to energy scavenging, and demonstrate

J. Rabaey; F. Burghardt; D. Steingart; M. Seeman; P. Wright

2007-01-01

204

Damping as a result of piezoelectric energy harvesting

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

205

Geometry optimization of a MEMS-based energy harvesting device

A MEMS based energy harvesting device is designed to convert mechanical vibration energy to electrical energy via piezoelectric effect. In order to improve the performances of the device, the geometry has been optimized by using moving mesh ALE model available in Comsol Multiphysics. The thickness, length and width of metal and ZnO are varied to get maximum displacement and voltage.

Suyog N Jagtap; Roy Paily

2011-01-01

206

Micro-fabricated silicon spiral spring based electromagnetic energy harvester

NASA Astrophysics Data System (ADS)

In this study, an electromagnetic energy harvester using a bulk micromachined silicon spiral spring and a polydimethylsiloxane (PDMS) packaging technique was fabricated and characterized to generate electrical energy from ultra-low ambient vibrations under at vibration accelerations 0.3g. The proposed energy harvester was comprised of a highly-miniaturized neodymium-ironboron (NdFeB) magnet, a silicon spiral spring, a multi-turn copper coil, and a PDMS housing in order to improve its electrical output power and reduce its size/volume. When an external vibration directly moves the mounted magnet as a seismic mass at the center of the spiral spring, the mechanical energy of the moving mass was transformed into electrical energy through the 183 turns of the solenoid copper coil. Silicon spiral springs were used to generate a high electrical output power by maximizing the deflection of the movable mass in response to low-level vibrations. The fabricated energy harvester exhibited a resonant frequency of 36 Hz and an optimal load resistance of 99 ?. It generated an output power of 29.02 µW and load voltage of 107.3 mV at a vibration acceleration of 0.3g. It also exhibited a power density and normalized power density of 48.37 µW·cm-3 and 537.41 µW·cm-3·g-2, respectively. The total volume of the fabricated energy harvester was 1 cm × 1 cm × 0.6 cm (height).

Bang, Dong Hyun; Park, Jae Yeong

2013-06-01

207

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

208

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

209

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

210

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

211

Piezoelectric Energy Harvesting Device Optimization by Synchronous Electric Charge Extraction

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

212

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

213

Implementation of a piezoelectric energy harvester in railway health monitoring

NASA Astrophysics Data System (ADS)

With development of wireless sensor technology, wireless sensor network has shown a great potential for railway health monitoring. However, how to supply continuous power to the wireless sensor nodes is one of the critical issues in long-term full-scale deployment of the wireless smart sensors. Some energy harvesting methodologies have been available including solar, vibration, wind, etc; among them, vibration-based energy harvester using piezoelectric material showed the potential for converting ambient vibration energy to electric energy in railway health monitoring even for underground subway systems. However, the piezoelectric energy harvester has two major problems including that it could only generate small amount of energy, and that it should match the exact narrow band natural frequency with the excitation frequency. To overcome these problems, a wide band piezoelectric energy harvester, which could generate more power on various frequencies regions, has been designed and validated with experimental test. Then it was applied to a full-scale field test using actual railway train. The power generation of the wide band piezoelectric array has been compared to a narrow-band, resonant-based, piezoelectric energy harvester.

Li, Jingcheng; Jang, Shinae; Tang, Jiong

2014-03-01

214

Flow energy piezoelectric bimorph nozzle harvester

NASA Astrophysics Data System (ADS)

There is a need for a long-life power generation scheme that could be used downhole in an oil well to produce 1 Watt average power. There are a variety of existing or proposed energy harvesting schemes that could be used in this environment but each of these has its own limitations. The vibrating piezoelectric structure is in principle capable of operating for very long lifetimes (decades) thereby possibly overcoming a principle limitation of existing technology based on rotating turbo-machinery. In order to determine the feasibility of using piezoelectrics to produce suitable flow energy harvesting, we surveyed experimentally a variety of nozzle configurations that could be used to excite a vibrating piezoelectric structure in such a way as to enable conversion of flow energy into useful amounts of electrical power. These included reed structures, spring mass-structures, drag and lift bluff bodies and a variety of nozzles with varying flow profiles. Although not an exhaustive survey we identified a spline nozzle/piezoelectric bimorph system that experimentally produced up to 3.4 mW per bimorph. This paper will discuss these results and present our initial analyses of the device using dimensional analysis and constitutive electromechanical modeling. The analysis suggests that an order-of-magnitude improvement in power generation from the current design is possible.

Sherrit, Stewart; Lee, Hyeong Jae; Walkemeyer, Phillip; Hasenoehrl, Jennifer; Hall, Jeffrey L.; Colonius, Tim; Tosi, Luis Phillipe; Arrazola, Alvaro; Kim, Namhyo; Sun, Kai; Corbett, Gary

2014-04-01

215

Integrated stabilized photovoltaic energy harvester

In this paper a photovoltaic power generator is presented. The energy harvesting device exploits the power generated by several on-chip micro-photovoltaic cells, connected in series, to provide the supply voltage and the reference voltages for an integrated voltage regulator. The regulator operates also with low illumination levels or large load currents, and tolerates a wide variation of the voltage produced

M. Ferri; D. Pinna; P. Malcovati; E. Dallago; G. Ricotti

2009-01-01

216

Sunrise for energy harvesting products

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

217

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

218

Energy harvesting with coupled magnetostrictive resonators

NASA Astrophysics Data System (ADS)

We report the investigation of an energy harvesting system composed of coupled resonators with the magnetostrictive material Galfenol (FeGa). A coupled system of meso-scale (1-10 cm) cantilever beams for harvesting vibration energy is described for powering and aiding the performance of low-power wireless sensor nodes. Galfenol is chosen in this work for its durability, compared to the brittleness often encountered with piezoelectric materials, and high magnetomechanical coupling. A lumped model, which captures both the mechanical and electrical behavior of the individual transducers, is first developed. The values of the lumped element parameters are then derived empirically from fabricated beams in order to compare the model to experimental measurements. The governing equations of the coupled system lead to a system of differential equations with all-to-all coupling between transducers. An analysis of the system equations reveals different patterns of collective oscillations. Among the many different patterns, a synchronous state appears to yield the maximum energy that can be harvested by the system. Experiments on coupled system shows that the coupled system exhibits synchronization and an increment in the output power. Discussion of the required power converters is also included.

Naik, Suketu; Phipps, Alex; In, Visarath; Cavaroc, Peyton; Matus-Vargas, Antonio; Palacios, Antonio; Gonzalez-Hernandez, H. G.

2014-03-01

219

Energy harvesting devices for harvesting energy from terahertz electromagnetic radiation

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.; Kotter, Dale K.; Pinhero, Patrick J.

2012-10-09

220

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

221

NASA Astrophysics Data System (ADS)

The challenge of variable vibration frequencies for energy harvesting calls for the development of wideband energy harvesters. Bistability has been proven to be a potential solution. Optimization of the energy extraction is another important objective for energy harvesting. Nonlinear synchronized switching techniques have demonstrated some of the best performances. This paper presents a novel energy harvesting solution which combines these two techniques: the OSECE (optimized synchronous electric charge extraction) technique is used along with a BSM (buckled-spring-mass) bistable generator to achieve wideband energy harvesting. The effect of the electromechanical coupling coefficient on the harvested power for the bistable harvester with the nonlinear energy extraction technique is discussed for the first time. The performances of the proposed solution for different levels of electromechanical coupling coefficients in the cases of chirp and noise excitations are compared against the performances of the bistable harvester with the standard technique. It is shown that the OSECE technique is a much better option for wideband energy harvesting than the standard circuit. Moreover, the harvested energy is drastically increased for all excitations in the case of low electromechanical coupling coefficients. When the electromechanical coupling coefficient is high, the performance of the OSECE technique is not as good as the standard circuit for forward sweeps, but superior for the reverse sweep and band-limited noise cases. However, considering that real excitation signals are more similar to noise signals, the OSECE technique enhances the performance.

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

2013-12-01

222

Flexible and Robust Multilayer Micro-Vibrational Harvesters for High Acceleration Environments

NASA Astrophysics Data System (ADS)

This paper presents the fabrication and characterization of multilayer PVDF resonant micro-vibrational energy harvesters designed to withstand environments in which high levels of acceleration are present. The multilayer cantilevers are fabricated by combining two folded PVDF stacks into a multilayered, bimorph structure. This acts to increase the overall capacitance of the harvester, a problem that plaques PVDF cantilevers as a result of its low dielectric constant. Moderate powers (7 ?W) are produced from the cantilevers even at high acceleration levels (20 g) due to the limited piezoelectric coefficient of PVDF; however, as a result of the high tensile strength and low elastic modulus of PVDF, the cantilevers are able to survive extremely high accelerations (> 4000 g) without breakage - a critical problem for harvesters based on brittle piezoelectric materials and substrates.

Lockhart, R.; Dauksevicius, R.; Vasquez Quintero, A.; Janphuang, P.; Briand, D.; de Rooij, N. F.

2013-12-01

223

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

224

Scaling prospects in mechanical energy harvesting with piezo nanowires

NASA Astrophysics Data System (ADS)

The combination of 3D processing technologies, low power circuits and new materials integration makes it conceivable to build autonomous integrated systems, which would harvest their energy from the environment. In this paper, we focus on mechanical energy harvesting and discuss its scaling prospects toward the use of piezoelectric nanostructures, able to be integrated in a CMOS environment. It is shown that direct scaling of present MEMS-based methodologies would be beneficial for high-frequency applications only. For the range of applications which is presently foreseen, a different approach is needed, based on energy harvesting from direct real-time deformation instead of energy harvesting from vibration modes at or close to resonance. We discuss the prospects of such an approach based on simple scaling rules Contribution to the Topical Issue “International Semiconductor Conference Dresden-Grenoble - ISCDG 2012”, Edited by Gérard Ghibaudo, Francis Balestra and Simon Deleonibus.

Ardila, Gustavo; Hinchet, Ronan; Mouis, Mireille; Montès, Laurent

2013-07-01

225

Energy-harvesting power sources for very-high-G gun-fired munitions

Several novel classes of piezoelectric-based energy-harvesting power sources are presented for very high-G gun-fired munitions (40,000 - 240,000 Gs). The power sources are designed to harvest energy from the firing acceleration and in certain applications also from in-flight vibrations. The harvested energy is converted to electrical energy for powering onboard electronics, and can provide enough energy to eliminate the need

J. Rastegar; R. Murray; C. Pereira; H.-L. Nguyen

2010-01-01

226

Enhanced PVDF film for multi energy harvesting

NASA Astrophysics Data System (ADS)

PVDF is a very important piezoelectric polymer material which has a promising range of applications in a variety of fields such as acoustic sensors and transducers, electrical switches, medical instrumentation, artificial sensitive skin in robotics, automotive detection on roads, nondestructive testing, structural health monitoring and as a biocampatible material. In this research cantilever based multi energy harvester was developed to maximize the power output of PVDF sensor. Nano mixture containing ferrofluid (FF) and ZnO nano particles were used to enhance the piezoelectric output of the sensor. The samples were tested under different energy conditions to observe the behavior of nano coated PVDF film under multi energy conditions. Composition of the ZnO and FF nano particles were changed by weight, in order to achieve the optimal composition of the nano mixture. Light energy, vibration energy, combined effect of light and vibration energy, and magnetic effect were used to explore the behavior of the sensor. The sensor with 60% ZnO and 40% FF achieved a maximum power output of 10.7 microwatts when it is under the combined effect of light and vibration energy. Which is nearly 16 times more power output than PVDF sensor. When the magnetic effect is considered the sensor with 100% FF showed the highest power output of 11.2 microwatts which is nearly 17 times more power output than pure PVDF. The effective piezoelctric volume of the sensor was 0.017 cm3. In order to explore the effect of magnetic flux, cone patterns were created on the sensor by means of a external magnetic field. Stability of the cones generated on the sensor played a major role in generated power output.

Karunarathna, Ranmunige Nadeeka

227

Experimental study of a multi-impact energy harvester under low frequency excitations

NASA Astrophysics Data System (ADS)

The multi-impact energy harvester of the present study is a retrofitted piezoelectric based energy harvesting device that is designed especially for low frequency excitations. It consists of a spring–mass system and two piezoelectric cantilevers. By utilizing a series of impacts between the cantilevers and the moving mass, ambient vibrations of low frequencies can be up-converted into high frequency vibrations on the piezoelectric cantilevers and therefore generate usable electric energy. To examine the performance of the multi-impact harvester, a model is designed and machined for the experimental study. Sinusoidal vibrations and simulated bridge vibrations are used as the excitations for the harvester. A traditional cantilever piezoelectric harvester is also made for a performance comparison.

Zhang, Ye; Cai, C. S.; Zhang, Wei

2014-05-01

228

Power management in energy harvesting sensor networks

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

229

Adaptive duty cycling for energy harvesting systems

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

230

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

231

Conceptual design of rotary magnetostrictive energy harvester

NASA Astrophysics Data System (ADS)

This paper presents the conceptual design of a rotary magnetostrictive energy harvester (RMEH), which consists of one coil-wound Galfenol cantilever, with two PMs adhered onto the each end, and one permanent magnet (PM) array sandwiched between two wheels. Modeling and simulation are used to validate the concept. The proof-of-concept RMEH is fabricated by using the simulation results, and subjected to the experimental characterization. The experimental setup for the simulated characterization uses the motor-driven PM array to induce a forced vibration. It can be concluded that the theoretical prediction on the induced voltage agrees well with the experimental results and that induced voltage increases with rpm and with number of PMs. Future work includes optimization of RMEH performance via PM array configuration and development of prototype.

Park, Young-Woo; Kang, Han-Sam; Wereley, Norman M.

2014-05-01

232

Piezoelectric energy harvesting using a series synchronized switch technique

NASA Astrophysics Data System (ADS)

An alternative switching technique for piezoelectric energy harvesting is presented. The energy harvester based on piezoelectric elements is a promising method to scavenge ambient energy. Several non-linear techniques such as SSHI have been implemented to improve the global harvested energy. However, these techniques are sensitive to load and should be tuned to obtain optimal power output. This technique, called Series Synchronized Switch Harvesting (S3H), has both the advantage of easy implementation and independence of the harvested power with the load impedance. The harvesting circuit simply consists of a switch in series with the piezoelement and the load. The switch is nearly always open and is triggered-on each time the piezoelectric voltage reaches an extremum. It is opened back after an arbitrary on-time t0. The energy scavenging process happens when switch is closed. Based on linear motion assumption, the harvester structure is modeled as a "Mass-Spring-Damper" system. The analysis of S3H technique is considered with harmonic excitation. An analytical model of S3H is presented and discussed. The main advantage of this approach compared with the usual standard technique is that the extracted power is independent of the load within a wide range of load impedance, and that the useful impedance range is simply related to the defined switch on-time. For constant displacement excitation condition, the optimal power output is more than twice the power extracted by the standard technique as long as the on-time interval is small comparatively with the vibration period. For constant force excitation, an optimal on-time can be defined resulting in an optimally wide load bandwidth. Keywords: piezoelectric; energy harvesting; non-linear harvesting techniques; switching techniques.

Li, Yang; Lallart, Mickaël.; Richard, Claude

2014-04-01

233

Energy harvester apparatus having improved efficiency

US Patent & Trademark Office Database

An improved vibrational energy harvester includes a housing and at least one energy transducer. In an embodiment, a second mass element is arranged to receive collisionally transferred kinetic energy from a first mass element when the housing is in an effective state of mechanical agitation, resulting in relative motion between the housing and at least one of the second and further mass elements. The energy transducer is arranged to be activated by the resulting relative motion between the housing and at least one of the second and further mass elements. In a further embodiment, kinetic energy is collisionally transferred in a velocity-multiplying arrangement from the first to a second or further mass element that has a range of linear ballistic motion. The energy transducer is arranged to be activated, at least in part, by the ballistic motion of the second or further mass element. The energy transducer, or a portion of it, may be attached to the housing, or it may be attached to another of the mass elements.

2013-01-08

234

In this paper, we propose and demonstrate a novel approach to harvest energy from ambient vibration of which frequency is normally very low and varying. A natural phenomenon known as snap-through buckling is adapted to achieve highly efficient energy harvesting even at off-resonance input conditions. The proposed device was tested at low frequency vibration environment (1-50 Hz) in which resonance

Seok-Min Jung; Kwang-Seok Yun

2010-01-01

235

Design and modeling of a wideband MEMS-based energy harvester with experimental verification

In this paper, we propose a solution for the narrow band operation which is one of the main issues in the operation of vibration-based energy harvesters, i.e. micro power generators (MPGpsilas). The solution is based on utilizing piecewise-linear oscillators along with decreasing the effective damping ratio of the resonator. The system is modeled and a macro electromagnetic vibration-based energy harvester

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

2008-01-01

236

NASA Astrophysics Data System (ADS)

In this study, we developed a flexible energy harvester that uses the frequency up-conversion mechanism. The harvester is composed of a flexible piezoelectric cantilever and substrate, and it can scavenge energy from deformation or strain by converting it into a mechanical vibration of the cantilever. We found experimentally that the output voltage of the harvester not affected by an input frequency as long as the strain was large enough, and there was no lower limit of the input frequency. The critical strain, i.e., the threshold radius of curvature of the harvester, could be modulated by adjusting magnetic force; therefore, it is possible to optimally apply the harvester to various deformation ranges. The maximum and average power density at 0.5 Hz of input frequency was measured to be 320 ?W/cm2 and 6.8 ?W/cm2 for a resistive load of 10 M?.

Kwon, Dae-Sung; Ko, Hee-Jin; Kim, Min-Ook; Oh, Yongkeun; Sim, Jaesam; Lee, Kyounghoon; Cho, Kyung-Ho; Kim, Jongbaeg

2014-03-01

237

Harvesting energy from a cantilever piezoelectric beam

Energy harvesting using piezoelectric material 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, wearable computer concepts, as well as small portable electrical devices, are a few motivations that have ignited the study of piezoelectric energy harvesting. The theory

Sunghwan Kim; Thomas J. Johnson; William W. Clark

2004-01-01

238

NASA Astrophysics Data System (ADS)

Power harvesting techniques that convert vibration energy into electrical energy through piezoelectric transducers show strong potential for powering smart wireless sensor devices in applications of structural health monitoring. This paper presents an analytical model of the dynamic behavior of an electromechanical piezoelectric bimorph cantilever harvester connected with an AC-DC circuit based on the Euler-Bernoulli beam theory and Hamiltonian theorem. A new cantilevered piezoelectric bimorph structure is proposed in which the plug-type connection between support layer and tip-mass ensures that the gravity center of the tip-mass is collinear with the gravity center of the beam so that the brittle fracture of piezoelectric layers can also be avoided while vibrating with large amplitude. The tip-mass is equated by the inertial force and inertial moment acting at the end of the piezoelectric bimorph beam based on D'Alembert's principle. An AC-DC converting circuit soldered with the piezoelectric elements is also taken into account. A completely new analytic expression of the global behavior of the electromechanical piezoelectric bimorph harvesting system with AC-DC circuit under input base transverse excitation is derived. Moreover, an experimental energy harvester is fabricated and the theoretical analysis and experimental results of the piezoelectric harvester under the input base transverse displacement excitation are validated by using measurements of the absolute tip displacement, electric voltage response, electric current response and electric power harvesting.

Wang, Hongjin; Meng, Qingfeng

2013-03-01

239

Investigations of biomimetic light energy harvesting pigments

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Nature uses chlorophyll and other porphyrinic pigments to capture and transfer light energy as a preliminary step in photosynthesis. The design of synthetic assemblies of light harvesting and energy directing pigments has been explored through synthesis and characterization of porphyrin oligomers. In this project, pigment electronic and vibrational structures have been explored by electrochemistry and dynamic and static optical measurements. Transient absorption data reveal energy transfer between pigments with lifetimes on the order of 20--200 picoseconds, while Raman data reveal that the basic porphyrin core structure is unperturbed relative to the individual monomer units. These two findings, along with an extensive series of experiments on the oxidized oligomers, reveal that coupling between the pigments is fundamentally weak, but sufficient to allow facile energy transfer as the predominant excited state process. Modeling of the expected quantum yields for energy transfer within a variety of arrays was accomplished, thereby providing a tool to guide synthetic goals.

Van Patten, P.G.; Donohoe, R.J. [Los Alamos National Lab., NM (United States); Lindsey, J.S. [North Carolina State Univ., Raleigh, NC (United States); Bocian, D.F. [Univ. of California, Riverside, CA (United States)

1998-12-01

240

Experimental valitation of energy harvesting device for civil engineering applications

NASA Astrophysics Data System (ADS)

In the field of structural health monitoring using wireless sensors, considerable research attention has been recently given to vibration-based energy harvesting devices for exploring their feasibility as a power source of a wireless sensor node. Most of the previous studies have focused on lab-scale tests for performance validation. For real application, however, field tests on developed energy harvesting devices should be conducted, because their performance may be considerably affected by change in the testing environment. In this study, a new electromagnetic energy harvester is proposed, which is more suitable for civil engineering application, and the preliminary field test on a real cable-stayed bridge are conducted to validate its effectiveness.

Jung, Hyung-Jo; Kim, In-Ho; Park, Jeongsu

2012-03-01

241

Energy harvesting — from devices to systems

Energy harvesting micro-generators provide alternative sources of energy for many technical and personal applications. Since the power delivered by such miniaturized devices is limited they need to be optimized and adapted to the application. The associated electronics not only has to operate at very low voltages and use little power it also needs to be adaptive to the fluctuating harvesting

Yiannos Manoli; Fritz Huettinger

2010-01-01

242

Multimodal piezoelectric wind energy harvesters

NASA Astrophysics Data System (ADS)

We investigated energy harvesting from wind to electrical power using piezoelectric films. Commercial films with different areas (from 3 to 30 cm2) and thicknesses (40-64 µm) were used. The generated energy was rectified through a diode bridge and delivered to a storage capacitor. Two different wind flows were investigated: laminar flow from a wind tunnel and turbulent flow from a dryer using three different setups and two wind incidences (parallel and normal). Piezofilms oscillating in wind flows were recorded using video cameras and electrical signals monitored with an oscilloscope. They were found to be stressed by travelling waves of different frequencies induced by wind turbulences. We propose a simple model based on sinusoidal current generators working at different frequencies. We studied the geometrical dependence of the piezofilm on the power generation. Power generation was found to be of the order of 0.2 µW for these particular sensors. Guidelines to significantly improve power generation are provided, taking into account a convenient geometrical design to match the piezofilm resonance frequency to the vortex generation frequency.

Ovejas, V. J.; Cuadras, A.

2011-08-01

243

Hybrid piezoelectric energy harvesting transducer system

NASA Technical Reports Server (NTRS)

A hybrid piezoelectric energy harvesting transducer system includes: (a) first and second symmetric, pre-curved piezoelectric elements mounted separately on a frame so that their concave major surfaces are positioned opposite to each other; and (b) a linear piezoelectric element mounted separately on the frame and positioned between the pre-curved piezoelectric elements. The pre-curved piezoelectric elements and the linear piezoelectric element are spaced from one another and communicate with energy harvesting circuitry having contact points on the frame. The hybrid piezoelectric energy harvesting transducer system has a higher electromechanical energy conversion efficiency than any known piezoelectric transducer.

Xu, Tian-Bing (Inventor); Jiang, Xiaoning (Inventor); Su, Ji (Inventor); Rehrig, Paul W. (Inventor); Hackenberger, Wesley S. (Inventor)

2008-01-01

244

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

245

NASA Astrophysics Data System (ADS)

Piezoelectric energy harvesting provides a means to harvest the ambient kinetic energy (e.g., vibrations and rotations) of structures for conversion into usable electricity. The technique can be employed to provide power sources for wireless sensors and low-power devices. Most energy harvesting devices developed to date operate most efficiently within a narrow bandwidth because they are resonance-frequency-based designs, although several tunable techniques have been proposed to broaden the efficient frequency range of energy harvesting. However, most efforts have focused on harvesting vibration energy rather than rotational energy. This paper presents the results of a comprehensive design analysis and experimental tests of a passive self-tuning piezoelectric composite cantilever beam for harvesting energy from rotational motion. The piezoelectric beam harvester is mounted on a rotating axis in the radial direction so that the tensile stress induced by the centrifugal force effectively stiffens the beam to passively tune the resonance frequency. A calculation procedure based on a finite element method is developed to analyze the self-frequency-tuning piezoelectric energy harvester, and the results are compared with those obtained from an analytic beam model. The design parameters for the self-tuning characteristics are identified and discussed. Experimental results verify the frequency-tuning energy harvesting behavior and show improved performances for the voltage and power outputs in the bandwidth.

Hsu, Jin-Chen; Tseng, Chih-Ta; Chen, Yi-Sheng

2014-07-01

246

Broadband energy harvesting using acoustic black hole structural tailoring

NASA Astrophysics Data System (ADS)

This paper explores the concept of an acoustic black hole (ABH) as a main design framework for performing dynamic structural tailoring of mechanical systems for vibration energy harvesting applications. The ABH is an integral feature embedded in the host structure that allows for a smooth reduction of the phase velocity, theoretically approaching zero, while minimizing the reflected energy. This mechanism results in structural areas with high energy density that can be effectively exploited to develop enhanced vibration-based energy harvesting. Fully coupled electro-mechanical models of an ABH tapered structure with surface mounted piezo-transducers are developed to numerically simulate the response of the system to both steady state and transient excitations. The design performances are numerically evaluated using structural intensity data as well as the instantaneous voltage/power and energy output produced by the piezo-transducer network. Results show that the dynamically tailored structural design enables a drastic increase in the harvested energy as compared to traditional structures, both under steady state and transient excitation conditions.

Zhao, Liuxian; Conlon, Stephen C.; Semperlotti, Fabio

2014-06-01

247

Ultrasound acoustic wave energy transfer and harvesting

NASA Astrophysics Data System (ADS)

This paper investigates low-power electricity generation from ultrasound acoustic wave energy transfer combined with piezoelectric energy harvesting for wireless applications ranging from medical implants to naval sensor systems. The focus is placed on an underwater system that consists of a pulsating source for spherical wave generation and a harvester connected to an external resistive load for quantifying the electrical power output. An analytical electro-acoustic model is developed to relate the source strength to the electrical power output of the harvester located at a specific distance from the source. The model couples the energy harvester dynamics (piezoelectric device and electrical load) with the source strength through the acoustic-structure interaction at the harvester-fluid interface. Case studies are given for a detailed understanding of the coupled system dynamics under various conditions. Specifically the relationship between the electrical power output and system parameters, such as the distance of the harvester from the source, dimensions of the harvester, level of source strength, and electrical load resistance are explored. Sensitivity of the electrical power output to the excitation frequency in the neighborhood of the harvester's underwater resonance frequency is also reported.

Shahab, Shima; Leadenham, Stephen; Guillot, François; Sabra, Karim; Erturk, Alper

2014-04-01

248

Low energy dissipation electric circuit for energy harvesting

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

249

Damping as a result of piezoelectric energy harvesting

NASA Astrophysics Data System (ADS)

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 energy. The removal of mechanical energy from a vibrating structure necessarily results in damping. This research addresses the damping associated with a piezoelectric energy harvesting system that consists of a full-bridge rectifier, a filter capacitor, a switching DC-DC step-down converter, and a battery. Under conditions of harmonic forcing, the effective modal loss factor depends on: (1) the electromechanical coupling coefficient of the piezoelectric system; and (2) the ratio of the rectifier output voltage during operation to its maximum open-circuit value. When the DC-DC converter is maximizing power flow to the battery, this voltage ratio is very nearly 1/2, and the loss factor depends only on the coupling coefficient. Experiments on a base-driven piezoelectric cantilever, having a system coupling coefficient of 26%, yielded an effective loss factor for the fundamental vibration mode of 2.2%, in excellent agreement with theory.

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

2004-01-01

250

Mechanical vibration to electrical energy converter

Electromechanical devices that generate an electrical signal in response to an external source of mechanical vibrations can operate as a sensor of vibrations and as an energy harvester for converting mechanical vibration to electrical energy. The devices incorporate a magnet that is movable through a gap in a ferromagnetic circuit, wherein a coil is wound around a portion of the ferromagnetic circuit. A flexible coupling is used to attach the magnet to a frame for providing alignment of the magnet as it moves or oscillates through the gap in the ferromagnetic circuit. The motion of the magnet can be constrained to occur within a substantially linear range of magnetostatic force that develops due to the motion of the magnet. The devices can have ferromagnetic circuits with multiple arms, an array of magnets having alternating polarity and, encompass micro-electromechanical (MEM) devices.

Kellogg, Rick Allen (Tijeras, NM); Brotz, Jay Kristoffer (Albuquerque, NM)

2009-03-03

251

A 2DOF wideband electrostatic transducer for energy harvesting and implantable applications

This paper reports the modeling, fabrication and characterization of a SOI-based electro-mechanical transducer used for energy harvesting. The electrostatic transducer couples the ultrasonic energy with the vibration of a seismic mass, converting ultrasonic mechanical energy into electrical energy by means of polarized movable capacitor with comb structures. To extract ambient kinetic energy with arbitrary motion directions, this paper introduces a

Y. Zhu; S. O. R. Moheimani; M. R. Yuce

2009-01-01

252

A novel miniature thermomagnetic energy harvester

NASA Astrophysics Data System (ADS)

Nowadays, thermal-energy-harvesting is an important research topic for powering wireless sensors. Among numerous thermal-energy-harvesting approaches, some researchers demonstrated novel thermomagnetic-energy harvesters to convert a thermal-energy from an ambient temperature-difference to an electrical-output to power the sensors. However, the harvesters are too bulky to be integrated with the sensors embedded in tiny mechanical-structures for some structuralhealth- monitoring applications. Therefore, miniaturized harvesters are needed. Hence, we demonstrate a miniature thermomagnetic-energy harvester. The harvester consists of CuBe-beams, PZT-piezoelectric-sheet, Gd-soft-magnet, NdFeB-hard-magnet, and mechanical-frame. The piezoelectric-sheet and soft-magnet is bounded at fixed-end and freeend of the beams, respectively. The mechanical-frame assembles the beams and hard-magnet. The length×width×thickness of the harvester is 2.5cm×1.7cm×1.5cm. According to this, our harvester is 20-times smaller than the other harvesters. In the initial-state of the energy-harvesting, the beams' free-end is near the cold-side. Thus, the soft-magnet is cooled lower than its curie temperature (Tc) and consequently changed from paramagnetic to ferromagnetic. Therefore, a magnetic-attractive force is produced between the soft-magnet and hard-magnet. Consequently, the beams/soft-magnet are down-pulled toward the hard-magnet fixed on the hot-side. The soft-magnet closing to the hot-side is heated higher than its Tc and subsequently changed to paramagnetic. Consequently, the magnetic-force is eliminated thus the beams are rebounded to the initial-state. Hence, when the harvester is under a temperature-difference, the beams' pulling-down/back process is cyclic. Due to the piezoelectric effect, the piezoelectric-sheet fixed on the beams continuously produces voltage-response. Under the temperature-difference of 29°C, the voltage-response of the harvester is 30.4 mV with an oscillating-frequency of 0.098 Hz.

Chen, Chin-Chung; Chung, Tien-Kan; Cheng, Chi-Cheng; Tseng, Chia-Yuan

2014-03-01

253

Extending the dynamic range of an energy harvester using nonlinear damping

NASA Astrophysics Data System (ADS)

This paper introduces the use of nonlinear damping for extending the dynamic range of vibration energy harvesters. A cubic nonlinear damper is initially considered and the average harvested power and the throw are obtained for different sinusoidal base excitation amplitudes and frequencies, both numerically and analytically. It is demonstrated that when excited at resonance, at an amplitude below its maximum operational limit, the harvested power using a nonlinear damper can be significantly larger than that of a linear energy harvester, therefore expanding its dynamic range. A potential approach to implementing cubic nonlinearity using a shunted electromagnetic device is also presented.

Ghandchi Tehrani, Maryam; Elliott, Stephen J.

2014-02-01

254

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

255

Energy harvesting MEMS device based on thin film piezoelectric cantilevers

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

256

Energy Harvesting on Highway Bridges.

National Technical Information Service (NTIS)

This project is investigating the potential for generating electrical power from the vibrations of a bridge due to large vehicles. It utilizes state-of-the-art technology and interdisciplinary expertise in solid-state electronics and bridge engineering to...

J. Nolan J. D. Baldwin L. Holliday S. Roswurm

2011-01-01

257

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

258

Impedance matching for broadband piezoelectric energy harvesting

NASA Astrophysics Data System (ADS)

This paper presents a system design for broadband piezoelectric energy harvesting by means of impedance matching. An inductive load impedance is emulated by controlling the output current of the piezoelectric harvester with a bipolar boost converter. The reference current is derived from the low pass filtered voltage measured at the harvester terminals. In order to maximize the harvested power especially for nonresonant frequencies the filter parameters are adjusted by a simple optimization algorithm. However the amount of harvested power is limited by the efficiency of the bipolar boost converter. Therefore an additional switch in the bipolar boost converter is proposed to reduce the capacitive switching losses. The proposed system is simulated using numerical parameters of available discrete components. Using the additional switch, the harvested power is increased by 20%. The proposed system constantly harvests 80% of the theoretically available power over frequency. The usable frequency range of ±4Hz around the resonance frequency of the piezoelectric harvester is mainly limited due to the boost converter topology. This comparison does not include the power dissipation of the control circuit.

Hagedorn, F.; Leicht, J.; Sanchez, D.; Hehn, T.; Manoli, Y.

2013-12-01

259

Characterization of a rotary hybrid multimodal energy harvester

NASA Astrophysics Data System (ADS)

In this study, experimental characterizations of a new hybrid energy harvesting device consisting of piezoelectric and electromagnetic transducers are presented. The generator, to be worn on the legs or arms of a person, harnesses linear motion and impact forces from human motion to generate electrical energy. The device consists of an unbalanced rotor made of three piezoelectric beams which have permanent magnets attached to the ends. Impact forces cause the beams to vibrate, generating a voltage across their electrodes and linear motion causes the rotor to spin. As the rotor spins, the magnets pass over ten electromagnetic coils mounted to the base, inducing a current through the wire. Several design related issues were investigated experimentally in order to optimize the hybrid device for maximum power generation. Further experiments were conducted on the system to characterize the energy harvesting capabilities of the device, all of which are presented in this study.

Larkin, Miles R.; Tadesse, Yonas

2014-04-01

260

This paper presents a novel approach for designing broadband piezoelectric harvesters by integrating multiple piezoelectric bimorphs (PBs) with different aspect ratios into a system. The effect of 2 connecting patterns among PBs, in series and in parallel, on improving energy harvesting performance is discussed. It is found for multifrequency spectra ambient vibrations: 1) the operating frequency band (OFB) of a harvesting structure can be widened by connecting multiple PBs with different aspect ratios in series; 2) the OFB of a harvesting structure can be shifted to the dominant frequency domain of the ambient vibrations by increasing or decreasing the number of PBs in parallel. Numerical results show that the OFB of the piezoelectric energy harvesting devices can be tailored by the connection patterns (i.e., in series and in parallel) among PBs. PMID:18986908

Xue, Huan; Hu, Yuantai; Wang, Qing-Ming

2008-09-01

261

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

262

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

263

Criterion for material selection in design of bulk piezoelectric energy harvesters.

Vibration energy harvesting has gained tremendous attention in the past decade and continues to grow rapidly. There are various transduction mechanisms for converting the vibration energy into electrical energy, out of which the piezoelectric mechanism has been shown to provide advantages at the micro-to-meso scale. In the past few years, several studies have tried to address the question of which piezoelectric composition is better for energy harvesting; however, discussion on this subject continues. The intent of this letter is to provide an answer for this question through a simple criterion which can be used in routine material evaluation. PMID:21156356

Priya, Shashank

2010-12-01

264

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

265

Ultra Low-Voltage Energy Harvesting.

National Technical Information Service (NTIS)

The U.S. Navy has many opportunities to take advantage of energy sources that are usually wasted because these low power sources yield such low- voltages that a normal voltage converter is not efficient enough to harvest the energy. Low-voltage energy is ...

A. P. Cabiling

2013-01-01

266

Helmholtz Resonator for Lead Zirconate Titanate Acoustic Energy Harvester

NASA Astrophysics Data System (ADS)

Acoustic energy harvesters that function in environments where sound pressure is extremely high (~150 dB), such as in engine rooms of aircrafts, are expected to be capable of powering wireless health monitoring systems. This paper presents the power generation performances of a lead-zirconate-titanate (PZT) acoustic energy harvester with a vibrating PZT diaphragm. The diaphragm had a diameter of 2 mm, consisting of Al(0.1 ?m)/PZT(1 ?m)/Pt(0.1 ?m)/Ti(0.1 ?m)/SiO2(1.5 ?m). The harvester generated a power of 1.7×10-13 W under a sound pressure level of 110 dB at the first resonance frequency of 6.28 kHz. It was found that the generated power was increased to 6.8×10-13 W using a sound-collecting Helmholtz resonator cone with the height of 60 mm. The cone provided a Helmholtz resonance at 5.8 kHz, and the generated power increased from 3.4×10-14 W to 1.4×10-13 W at this frequency. The cone was also effective in increasing the bandwidth of the energy harvester.

Matsuda, Tomohiro; Tomii, Kazuki; Hagiwara, Saori; Miyake, Shuntaro; Hasegawa, Yuichi; Sato, Takamitsu; Kaneko, Yuta; Nishioka, Yasushiro

2013-12-01

267

Flat inductors for human motion energy harvesting

NASA Astrophysics Data System (ADS)

The human motion energy harvesting is under investigation. The aim of this investigation: to develop electromagnetic human motion energy harvester that will consist only from flat elements and is integrable into the apparel. Main parts of the developed human motion energy harvester are flat, spiral-shaped inductors. Voltage pulses in such flat inductors can be induced during the motion of a permanent magnet along it. Due to the flat structure, inductors can be completely integrated into the parts of the clothes and it is not necessary to keep empty place for the movement of the magnet, as in usual electromagnetic harvesters. The prototype of the clothing, jacket with integrated electromagnetic human motion energy harvester with flat inductors is tested. The theoretical model for the induction of the electromotive force due to the magnet's movement is created for the basic shapes (round, rhombic, square) of the inductive elements and the results (shape of voltage pulse and generated energy) of the calculations are in a good qualitative and quantitative coincidence with an experimental research.

Blums, Juris; Terlecka, Galina; Gornevs, Ilgvars; Vilumsone, Ausma

2013-05-01

268

NASA Astrophysics Data System (ADS)

The fundamental features of nonlinear dynamical systems are investigated in the context of vibration-based energy harvesting. A generalized, global, multi-frequency resonance condition is shown to exist in nonlinear systems where the energy harvesting efficiency has been maximized. Results show that damping and modulation of the excitation play critical roles in facilitating the frequency match required for resonance by tuning the frequencies of the system and modifying the frequency content of the excitation.

Ma, T.; Zhang, H.

2014-05-01

269

Nonlinear optimization of acoustic energy harvesting using piezoelectric devices.

In the first part of the paper, a single degree-of-freedom model of a vibrating membrane with piezoelectric inserts is introduced and is initially applied to the case when a plane wave is incident with frequency close to one of the resonance frequencies. The model is a prototype of a device which converts ambient acoustical energy to electrical energy with the use of piezoelectric devices. The paper then proposes an enhancement of the energy harvesting process using a nonlinear processing of the output voltage of piezoelectric actuators, and suggests that this improves the energy conversion and reduces the sensitivity to frequency drifts. A theoretical discussion is given for the electrical power that can be expected making use of various models. This and supporting experimental results suggest that a nonlinear optimization approach allows a gain of up to 10 in harvested energy and a doubling of the bandwidth. A model is introduced in the latter part of the paper for predicting the behavior of the energy-harvesting device with changes in acoustic frequency, this model taking into account the damping effect and the frequency changes introduced by the nonlinear processes in the device. PMID:21110569

Lallart, Mickaeël; Guyomar, Daniel; Richard, Claude; Petit, Lionel

2010-11-01

270

Highly Efficient Low-frequency Energy Harvester Using Bulk Piezoelectric Ceramics

NASA Astrophysics Data System (ADS)

This paper describes a new way of manufacturing efficient vibration energy harvesters using thick films of piezoelectrics. The presented fabrication process is based on the thinning of high-density bulk Lead Zirconate Titanate (PZT) ceramic substrates, which enables the realization of thick layers (10-100 ?m). Using this fabrication approach, we prepared two types of cantilever-based vibration energy scavengers (unimorph and bimorph) operating at very low frequency (~15 Hz) with a 50 ?m PZT final thickness. Given that under a harmonic 10 mg vibration the harvested mean power was 1.3 ?W and 3 ?W respectively, these devices rank among the best ever-reported vibration energy scavengers according to commonly accepted figures of merit. The presented fabrication approach is therefore believed to be a good candidate for the manufacturing of highly efficient piezoelectric energy scavengers operating at very low frequency.

Colin, M.; Basrour, S.; Rufer, L.; Bantignies, C.; Nguyen-Dinh, A.

2013-12-01

271

Enhanced output power by eigenfrequency shift in acoustic energy harvester

NASA Astrophysics Data System (ADS)

In our previous studies, multiple piezoelectric cantilever plates were placed inside a quarter-wavelength straight tube resonator to harvest low frequency acoustic energy. To investigate the modification of eigenmodes in the tube resonator due to the presence of piezoelectric plates, the eigenfrequency shift properties by introducing single and multiple rectangular blockages in open-closed ducts are studied by using 1D segmented Helmholtz equations, Webster horn equation, and finite element simulations. The first-mode eigenfrequency of the duct is reduced when the blockage is placed near the open inlet. The decrease of eigenfrequency leads to the enhancement of absorbed acoustic power in the duct. Furthermore, the first half of the tube resonator possesses high pressure gradient resulting in larger driving forces for the vibration motion of piezoelectric plates. Therefore, in our harvesters, it is better to place the piezoelectric plates in the first half of the tube resonator to obtain high output voltage and power.

Li, Bin; You, Jeong Ho

2014-04-01

272

Electronic and Vibrational Coherences in Algal Light-Harvesting Proteins

NASA Astrophysics Data System (ADS)

We present broadband two-dimensional electronic spectra of a lightharvesting protein from photosynthetic algae. Analysis of the spectra show that the amplitude of the main cross peak oscillates as a function of the waiting time period. Both electronic coupling and intramolecular vibrational modes, and their mixture, can lead to such oscillations. Using predictions based on models of four-level systems, we describe ways to distinguish electronic from vibrational contributions to the coherence and find that both types of coupling contribute to the measured dynamics.

Turner, Daniel B.; Scholes, Gregory D.

2013-03-01

273

Energy scavenging from low frequency vibrations

NASA Astrophysics Data System (ADS)

The development of three energy conversion devices that are able to transform vibrations in their surroundings to electrical energy is discussed in this thesis. These energy harvesters are based upon a newly invented architecture called the Parametric Frequency Increased Generator (PFIG). The PFIG structure is designed to efficiently convert low frequency and non-periodic vibrations into electrical power. The three PFIG devices have a combined operating range covering two orders of magnitude in acceleration (0.54--19.6m/s 2) and a frequency range spanning up to 60Hz; making them some of the most versatile generators in existence. The PFIG utilizes a bi-stable mechanical structure to initiate high-frequency mechanical oscillations in an electromechanical scavenger. By up-converting the ambient vibration frequency to a higher internal operation frequency, the PFIG achieves better electromechanical coupling. The fixed internal displacement and dynamics of the PFIG allow it to operate more efficiently than resonant generators when the ambient vibration amplitude is higher than the internal displacement limit of the device. The PFIG structure is capable of efficiently converting mechanical vibrations with variable characteristics including amplitude and frequency, into electrical power. The first electromagnetic harvester can generate a peak power of 163microW and an average power of 13.6microW from an input acceleration of 9.8m/s 2 at 10Hz, and it can operate up to 60Hz. The internal volume of the generator is 2.12cm3 (3.75 including casing). It sets the state-of-the-art in efficiency in the <20Hz range. The volume figure of merit is 0.068%, which is a 10x improvement over other published works. It has a record high bandwidth figure of merit (0.375%). A second piezoelectric implementation generates 3.25microW of average power under the same excitation conditions, while the volume of the generator is halved (1.2cm3). A third PFIG was developed for critical infrastructure monitoring applications. It is used to harvest the very low-amplitude, low-frequency, and non-periodic vibrations present on bridges. The device generates 2.3microW of average power from an input acceleration of 0.54m/s2 at only 2Hz. The internal volume of the generator is 43cm3. It can operate over an unprecedentedly large acceleration (0.54--9.8m/s2) and frequency range (up to 30Hz) without any modifications or tuning.

Galchev, Tzeno V.

274

NASA Astrophysics Data System (ADS)

Power harvesters that extract energy from vibrating systems via piezoelectric transduction show strong potential for powering smart wireless sensor devices in applications of health condition monitoring of rotating machinery and structures. This paper presents an analytical method for modelling an electromechanical piezoelectric bimorph beam with tip mass under two input base transverse and longitudinal excitations. The Euler-Bernoulli beam equations were used to model the piezoelectric bimorph beam. The polarity-electric field of the piezoelectric element is excited by the strain field caused by base input excitation, resulting in electrical charge. The governing electromechanical dynamic equations were derived analytically using the weak form of the Hamiltonian principle to obtain the constitutive equations. Three constitutive electromechanical dynamic equations based on independent coefficients of virtual displacement vectors were formulated and then further modelled using the normalised Ritz eigenfunction series. The electromechanical formulations include both the series and parallel connections of the piezoelectric bimorph. The multi-mode frequency response functions (FRFs) under varying electrical load resistance were formulated using Laplace transformation for the multi-input mechanical vibrations to provide the multi-output dynamic displacement, velocity, voltage, current and power. The experimental and theoretical validations reduced for the single mode system were shown to provide reasonable predictions. The model results from polar base excitation for off-axis input motions were validated with experimental results showing the change to the electrical power frequency response amplitude as a function of excitation angle, with relevance for practical implementation.

Lumentut, M. F.; Howard, I. M.

2013-03-01

275

Piezoelectric energy harvester under parquet floor

NASA Astrophysics Data System (ADS)

The design, fabrication and testing of piezoelectric energy harvesting modules for floors is described. These modules are used beneath a parquet floor to harvest the energy of people walking over it. The harvesting modules consist of monoaxial stretched PVDF-foils. Multilayer modules are built up as roller-type capacitors. The fabrication process of the harvesting modules is simple and very suitable for mass production. Due to the use of organic polymers, the modules are characterized by a great flexibility and the possibility to create them in almost any geometrical size. The energy yield was determined depending on the dynamic loading force, the thickness of piezoelectric active material, the size of the piezoelectric modules, their alignment in the walking direction and their position on the floor. An increase of the energy yield at higher loading forces and higher thicknesses of the modules was observed. It was possible to generate up to 2.1mWs of electric energy with dynamic loads of 70kg using a specific module design. Furthermore a test floor was assembled to determine the influence of the size, alignment and position of the modules on the energy yield.

Bischur, E.; Schwesinger, N.

2011-03-01

276

Finite element modeling of piezoelectric energy harvesters

NASA Astrophysics Data System (ADS)

This article reports a novel finite element model of piezoelectric energy harvesters accounting for the effect of nonlinear interface circuits. The idea is to replace the energy harvesting circuit in parallel with the parasitic piezoelectric capacitance by an equivalent load impedance. This approach offers many advantages. First, the model itself can be implemented conveniently in commercial finite element softwares. Second, it directly provides system-level designs on the whole without resorting to circuit solvers. Third, the extensions to complicated structures such as array configurations are straightforward. The proposed finite element model is validated by considering the case of an array system endowed with the standard, parallel-/series-SSHI (synchronized switch harvesting on inductor) interfaces. Good agreement is found between simulation results and analytic estimates.

Wu, P. H.; Shu, Y. C.

2014-03-01

277

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

278

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

279

Acoustic energy harvesting using an electromechanical Helmholtz resonator.

This paper presents the development of an acoustic energy harvester using an electromechanical Helmholtz resonator (EMHR). The EMHR consists of an orifice, cavity, and a piezoelectric diaphragm. Acoustic energy is converted to mechanical energy when sound incident on the orifice generates an oscillatory pressure in the cavity, which in turns causes the vibration of the diaphragm. The conversion of acoustic energy to electrical energy is achieved via piezoelectric transduction in the diaphragm of the EMHR. Moreover, the diaphragm is coupled with energy reclamation circuitry to increase the efficiency of the energy conversion. Lumped element modeling of the EMHR is used to provide physical insight into the coupled energy domain dynamics governing the energy reclamation process. The feasibility of acoustic energy reclamation using an EMHR is demonstrated in a plane wave tube for two power converter topologies. The first is comprised of only a rectifier, and the second uses a rectifier connected to a flyback converter to improve load matching. Experimental results indicate that approximately 30 mW of output power is harvested for an incident sound pressure level of 160 dB with a flyback converter. Such power level is sufficient to power a variety of low power electronic devices. PMID:18397006

Liu, Fei; Phipps, Alex; Horowitz, Stephen; Ngo, Khai; Cattafesta, Louis; Nishida, Toshikazu; Sheplak, Mark

2008-04-01

280

Integrated solar energy harvesting and storage

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

281

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

282

NASA Astrophysics Data System (ADS)

We employ an analytical model of a harmonically excited bistable vibration energy harvester to determine criteria governing continuous high-energy orbit (HEO) dynamics that maximize harvesting performance. Derivation of the criteria stems from previously unexplored dynamic relationships predicted by the model indicating critical conditions for HEO; experimental evidence of the phenomenon is provided as validation. The criteria are vastly more concise than existing HEO prediction methodology and can more accurately delineate HEO boundaries. This research addresses an essential need to create effective tools for high performance and robust bistable harvester design.

Harne, R. L.; Thota, M.; Wang, K. W.

2013-02-01

283

Circuits for energy harvesting sensor signal processing

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

284

A MEMS-based wideband piezoelectric energy harvester system using mechanical stoppers

A piezoelectric MEMS energy harvester (EH) system with top- and bottom-stoppers can response to vibrations with frequency ranging from 30 Hz to 48 Hz when the top- and bottom-stopper distances are 0.75 mm and 1.1 mm, respectively, and the acceleration of vibration is 0.6 g. By adjusting the stopper distance, the operating bandwidth is broadened from the initial mechanical resonance

Huicong Liu; Chengkuo Lee; Takeshi Kobayashi; Cho Jui Tay; Chenggen Quan

2011-01-01

285

Impedance matching for improving piezoelectric energy harvesting systems

NASA Astrophysics Data System (ADS)

In a piezoelectric energy harvesting (PEH) system, the dynamics of the device as well as the energy flow within the system vary with different harvesting interface circuits connected. Meanwhile, the impedance matching theory is regarded as theoretical base for harvesting power enhancement, and hopefully could provide guidance for harvesting interface optimization. Most previous literatures on impedance matching for PEH started their analyses by assuming that the harvesting interface, which is nonlinear in nature, can be equalized to resistive load, or linear load whose impedance value can be arbitrarily set, so that the output impedance of the piezoelectric structure can surely be matched. Yet, after investigating the equivalent impedances of the existing harvesting interfaces, including standard energy harvesting (SEH), parallel synchronized switching harvesting on inductor (P-SSHI), and series synchronized switching harvesting on inductor (S-SSHI), we found that, their ranges are in fact limited. Therefore, to optimize the harvesting power, constrained matching instead of free matching should be adopted. In addition, we also clarify some confusing points in the previous literatures on impedance matching for energy harvesting. With the understanding on energy flow within piezoelectric devices, we know that only a portion of the extracted energy is able to be harvested, while the other is dissipated throughout the harvesting process. So even the extracted power from the source is maximized by matching the impedance; there is no guarantee that harvesting power is surely improved. The harvesting power also depends on the ratio between harvested energy and dissipated energy. These two issues discussed in this paper are crucial to improve the harvesting power and efficiency in piezoelectric energy harvesting systems.

Liang, Junrui; Liao, Wei-Hsin

2010-03-01

286

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

287

Design and power management of energy harvesting embedded systems

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

288

Energy harvesting for human wearable and implantable bio-sensors

There are clear trade-offs between functionality, battery lifetime and battery volume for wearable and implantable wireless-biosensors which energy harvesting devices may be able to overcome. Reliable energy harvesting has now become a reality for machine condition monitoring and is finding applications in chemical process plants, refineries and water treatment works. However, practical miniature devices that can harvest sufficient energy from

Paul D. Mitcheson

2010-01-01

289

Energy Harvesting Devices Using Macro-fiber Composite Materials

This study addresses the experimental validation of a design methodology for an energy harvesting device utilizing macro-fiber composite (MFC) materials. The energy harvesting device is composed of a cantilever beam with MFC elements, a tip mass, a rectifier, and an electrical resistance. A theoretical model of the energy harvesting device was developed for the estimation of generated power, voltage, and

Hyun Jeong Song; Young-Tai Choi; Norman M. Wereley; Ashish S. Purekar

2010-01-01

290

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

291

Nonlinear analysis of piezoelectric nanocomposite energy harvesting plates

NASA Astrophysics Data System (ADS)

This paper investigates the nonlinear analysis of energy harvesting from piezoelectric functionally graded carbon nanotube reinforced composite plates under combined thermal and mechanical loadings. The excitation, which derives from harmonically varying mechanical in-plane loading, results in parametric excitation. The governing equations of the piezoelectric functionally graded carbon nanotube reinforced composite plates are derived based on classical plate theory and von Kármán geometric nonlinearity. The material properties of the nanocomposite plate are assumed to be graded in the thickness direction. The single-walled carbon nanotubes (SWCNTs) are assumed to be aligned, straight and have a uniform layout. The linear buckling and vibration behavior of the nanocomposite plates is obtained in the first step. Then, Galerkin’s method is employed to derive the nonlinear governing equations of the problem with cubic nonlinearities associated with mid-plane stretching. Periodic solutions are determined by using the Poincaré–Lindstedt perturbation scheme with movable simply supported boundary conditions. The effects of temperature change, the volume fraction and the distribution pattern of the SWCNTs on the parametric resonance, in particular the amplitude of vibration and the average harvested power of the smart functionally graded carbon nanotube reinforced composite plates, are investigated through a detailed parametric study.

Rafiee, M.; He, X. Q.; Liew, K. M.

2014-06-01

292

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

293

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

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

294

Strain Energy Harvesting for Wireless Sensor Networks

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

295

Power Management for Energy Harvesting Wireless Sensors

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

296

Development of a biomechanical energy harvester

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

297

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

298

A 3-DOF SOI MEMS ultrasonic energy harvester for implanted devices

NASA Astrophysics Data System (ADS)

This paper reports the design and testing of a microelectromechanical systems (MEMS) energy harvester that is designed to harvest electrical energy from an external source of ultrasonic waves. This mechanism is potentially suited to applications including the powering of implanted devices for biomedical applications. The harvester employs a novel 3-degree of freedom design, with electrical energy being generated from displacements of a proof mass via electrostatic transducers. A silicon-on-insulator MEMS process was used to fabricate the device, with experimental characterization showing that the harvester can generate 24.7 nW, 19.8 nW, and 14.5 nW of electrical power respectively through its x-, y-, and z-axis vibrational modes.

Fowler, A. G.; Moheimani, S. O. R.; Behrens, S.

2013-12-01

299

NASA Astrophysics Data System (ADS)

This paper introduces an innovative architecture of a piezoelectric harvester, which enables harvesting vibration energy at low frequency using the {33}-transduction mode of a piezoelectric element. Unlike cantilevers integrating ferroelectric material combined with interdigitated electrodes, the concept that we propose is based on the elongation/compression excitation of a piezoelectric bar.

Colin, M.; Mortier, Q.; Basrour, S.; Bencheikh, N.

2013-12-01

300

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

301

Integrated actuation and energy harvesting in prestressed piezoelectric synthetic jets

NASA Astrophysics Data System (ADS)

With the looming energy crisis compounded by the global economic downturn there is an urgent need to increase energy efficiency and to discover new energy sources. An approach to solve this problem is to improve the efficiency of aerodynamic vehicles by using active flow control tools such as synthetic jet actuators. These devices are able to reduce fuel consumption and streamlined vehicle design by reducing drag and weight, and increasing maneuverability. Hence, the main goal of this dissertation is to study factors that affect the efficiency of synthetic jets by incorporating energy harvesting into actuator design using prestressed piezoelectric composites. Four state-of-the-art piezoelectric composites were chosen as active diaphragms in synthetic jet actuators. These composites not only overcome the inherent brittle and fragile nature of piezoelectric materials but also enhance domain movement which in turn enhances intrinsic contributions. With these varying characteristics among different types of composites, the intricacies of the synthetic jet design and its implementation increases. In addition the electrical power requirements of piezoelectric materials make the new SJA system a coupled multiphysics problem involving electro-mechanical and structural-fluid interactions. Due to the nature of this system, a design of experiments approach, a method of combining experiments and statistics, is utilized. Geometric and electro-mechanical factors are investigated using a fractional factorial design with peak synthetic jet velocity as a response variable. Furthermore, energy generated by the system oscillations is harvested with a prestressed composite and a piezo-polymer. Using response surface methodology the process is optimized under different temperatures and pressures to simulate harsh environmental conditions. Results of the fractional factorial experimental design showed that cavity dimensions and type of signal used to drive the synthetic jet actuator were statistically significant factors when studying peak jet velocity. The Bimorph (˜50m/s) and the prestressed metal composite (˜45m/s) generated similar peak jet velocities but the later is the most robust of all tested actuators. In addition, an alternate input signal to the composite, a sawtooth waveform, leads to jets formed with larger peak velocities at frequencies above 15Hz. The optimized factor levels for the energy harvesting process were identified as 237.6kPa, 3.7Hz, 1MO and 12°C and the power density measured at these conditions was 24.27microW/mm3. Finally, the SJA is integrated with an energy harvesting system and the power generated is stored into a large capacitor and a rechargeable battery. After approximately six hours of operation 5V of generated voltage is stored in a 330microF capacitor with the prestressed metal composite as the harvester. It is then demonstrated that energy harvested from the inherent vibrations of a SJA can be stored for later use. Then, the system proposed in this dissertation not only improves on the efficiency of aerodynamic bodies, but also harvests energy that is otherwise wasted.

Mane, Poorna

302

Optimal energy management policies for energy harvesting sensor nodes

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

303

Self-powered smart blade: helicopter blade energy harvesting

NASA Astrophysics Data System (ADS)

A novel energy harvesting device powered by aeroelastic flutter vibrations is proposed to generate power for embedded wireless sensors on a helicopter rotor blade. Such wireless sensing and on-board power generation system would eliminate the need for maintenance intensive slip ring systems that are required for hardwired sensors. A model of the system has been developed to predict the response and output of the device as a function of the incident wind speed. A system of coupled equations that describe the structural, aerodynamic, and electromechanical aspects of the system are presented. The model uses semi-empirical, unsteady, nonlinear aerodynamics modeling to predict the aerodynamic forces and moments acting on the structure and to account for the effects of vortex shedding and dynamic stall. These nonlinear effects are included to predict the limit cycle behavior of the system over a range of wind speeds. The model results are compared to preliminary wind tunnel tests of a low speed aeroelastic energy harvesting experiment.

Bryant, Matthew; Fang, Austin; Garcia, Ephrahim

2010-03-01

304

Energy harvesting using a thermoelectric material

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

2008-07-08

305

Solar Energy Harvesting for ZigBee Electronics

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

306

The delocalized, anticorrelated component of pigment vibrations can drive nonadiabatic electronic energy transfer in photosynthetic light-harvesting antennas. In femtosecond experiments, this energy transfer mechanism leads to excitation of delocalized, anticorrelated vibrational wavepackets on the ground electronic state that exhibit not only 2D spectroscopic signatures attributed to electronic coherence and oscillatory quantum energy transport but also a cross-peak asymmetry not previously explained by theory. A number of antennas have electronic energy gaps matching a pigment vibrational frequency with a small vibrational coordinate change on electronic excitation. Such photosynthetic energy transfer steps resemble molecular internal conversion through a nested intermolecular funnel.

Tiwari, Vivek; Peters, William K.; Jonas, David M.

2013-01-01

307

The delocalized, anticorrelated component of pigment vibrations can drive nonadiabatic electronic energy transfer in photosynthetic light-harvesting antennas. In femtosecond experiments, this energy transfer mechanism leads to excitation of delocalized, anticorrelated vibrational wavepackets on the ground electronic state that exhibit not only 2D spectroscopic signatures attributed to electronic coherence and oscillatory quantum energy transport but also a cross-peak asymmetry not previously explained by theory. A number of antennas have electronic energy gaps matching a pigment vibrational frequency with a small vibrational coordinate change on electronic excitation. Such photosynthetic energy transfer steps resemble molecular internal conversion through a nested intermolecular funnel. PMID:23267114

Tiwari, Vivek; Peters, William K; Jonas, David M

2013-01-22

308

Design and analysis of a connected broadband multi-piezoelectric-bimorph- beam energy harvester.

The rapid growth of remote, wireless, and microelectromechanical system (MEMS) devices over the past decades has motivated the development of a self-powered system that can replace traditional electrochemical batteries. Piezoelectric energy harvesters are ideal for capturing energy from mechanical vibrations in the ambient environment. Numerous studies have been made of this application of piezoelectric energy conversion; however, the narrow frequency operation band has limited its application to generate useful power. In this paper, a broadband energy harvester with an array/matrix of piezoelectric bimorphs connected by springs has been designed and analyzed based on the 1-D piezoelectric beam equations. The predicted result shows that the operational frequency band can be enlarged significantly by carefully adjusting the small end masses, length of the beam and spring stiffness. An optimal selection of the load impedance to realize the maximum power output is discussed. The results provide an important foundation for future broadband energy harvester design. PMID:24859665

Zhang, Haifeng; Afzalul, Karim

2014-06-01

309

Potential Ambient Energy-Harvesting Sources and Techniques

ERIC Educational Resources Information Center

Ambient energy harvesting is also known as energy scavenging or power harvesting, and it is the process where energy is obtained from the environment. A variety of techniques are available for energy scavenging, including solar and wind powers, ocean waves, piezoelectricity, thermoelectricity, and physical motions. For example, some systems…

Yildiz, Faruk

2009-01-01

310

Issues in mathematical modeling of piezoelectric energy harvesters

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

311

Multi-source energy harvester for wildlife tracking

NASA Astrophysics Data System (ADS)

Sufficient power supply to run GPS machinery and transmit data on a long-term basis remains to be the key challenge for wildlife tracking technology. Traditional way of replacing battery periodically is not only time and money consuming but also dangerous to live-trapping wild animals. In this paper, an innovative wildlife tracking device with multi-source energy harvester with advantage of high efficiency and reliability is investigated and developed. This multi-source energy harvester entails a solar energy harvester and an innovative rotational electromagnetic energy harvester is mounted on the "wildlife tracking collar" which will remarkably extend the duration of wild life tracking. A feedforward and feedback control of DC-DC converter circuit is adopted to passively realize the Maximum Power Point Tracking (MPPT) logic for the solar energy harvester. The rotational electromagnetic energy harvester can mechanically rectify the irregular bidirectional motion into unidirectional motion has been modeled and demonstrated.

Wu, You; Zuo, Lei; Zhou, Wanlu; Liang, Changwei; McCabe, Michael

2014-03-01

312

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

313

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

314

A low-loss hybrid rectification technique for piezoelectric energy harvesting

NASA Astrophysics Data System (ADS)

Embedded systems have decreased in size and increased in capability; however, small-scale energy storage technologies still significantly limit these advances. Energy neutral operation using small-scale energy harvesting technologies would allow for longer device operation times and smaller energy storage masses. Vibration energy harvesting is an attractive method due to the prevalence of energy sources in many environments. Losses in efficiency due to AC-DC rectification and conditioning circuits limit its application. This work presents a low-loss hybrid rectification technique for piezoelectric vibration energy harvesting using magnetically actuated reed switches and a passive semiconductor full-bridge rectifier. This method shows the capability to have higher efficiency levels and the rectification of low-voltage harvesters without the need for active electrical components. A theoretical model shows that the hybrid rectification technique performance is highly dependent on the proximity delay and the hysteresis behavior of the reed switches. Experimental results validate the model and support the hypothesis of increased performance using the hybrid rectification technique.

Schlichting, A. D.; Fink, E.; Garcia, E.

2013-09-01

315

Parametrization of ambient energy harvesters for complementary balanced electronic applications

NASA Astrophysics Data System (ADS)

The specific technical challenges associated with the design of an ambient energy powered electronic system currently requires thorough knowledge of the environment of deployment, energy harvester characteristics and power path management. In this work, a novel flexible model for ambient energy harvesters is presented that allows decoupling of the harvester's physical principles and electrical behavior using a three dimensional function. The model can be adapted to all existing harvesters, resulting in a design methodology for generic ambient energy powered systems using the presented model. Concrete examples are included to demonstrate the versatility of the presented design in the development of electronic appliances on system level.

Verbelen, Yannick; Braeken, An; Touhafi, Abdellah

2013-05-01

316

Magnetocaloric piezoelectric composites for energy harvesting

NASA Astrophysics Data System (ADS)

Magnetocaloric alloy, Gd5Si2Ge2, was developed into a composite with the poly(vinylidene fluoride) (PVDF) piezoelectric polymer. This multifunctional material possesses unique properties that are suitable for energy conversion and harvesting. Experimental approaches include using an arc melting technique to synthesize the Gd5Si2Ge2 (GSG) alloy and the spinning casting method to fabricate the composite. The materials were characterized using various techniques at different length scales. These include atomic force microscopy (AFM), optical microscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS). The results indicated that the phase transformation of the magnetocaloric material close to its Curie temperature induced a significant increase in power generation in the piezoelectric polymer. The power output of a laminated structure was 1.1 mW, more than 200 thousand times higher than the piezoelectric materials alone (5.1 nW).

Cleveland, Michael; Liang, Hong

2012-04-01

317

Energy harvesting with piezoelectric applied on shoes

NASA Astrophysics Data System (ADS)

In the last few years the continuous demand of energy saving has brought continuous research on low-power devices, energy storage and new sources of energy. Energy harvesting is an interesting solution that captures the energy from the environment that would otherwise be wasted. This work presents an electric-mechanical model of a piezoelectric transducer in a cantilever configuration. The model has been characterized measuring the acceleration and the open circuit voltage of a piezoelectric cantilever subjected to a sinusoidal force with different values frequency and subject to an impulsive force. The model has been used to identify the optimal position in which the piezoelectric cantilever has to be placed on a shoe in order to obtain the maximum energy while walking or running. As a second step we designed the DC-DC converter with an hysteresis comparator. The circuit is able to give energy to switch on a microprocessor for the amount of time long enough to capture and store the information required. The complete system has been implemented, installed on a shoe and used in a 10 Km running competition.

Camilloni, Enrico; Carloni, Mirko; Giammarini, Marco; Conti, Massimo

2013-05-01

318

Recent interest in using forest residues and small-diameter material for biofuels is generating a renewed focus on harvesting impacts and forest sustainability. The rich legacy of research from whole-tree harvesting studies can be examined in light of this interest. Although this research largely focused on consequences for forest productivity, in particular carbon and nutrient pools, it also has relevance for examining potential consequences for biodiversity and aquatic ecosystems. This review is framed within a context of contrasting ecosystem impacts from whole-tree harvesting because it represents a high level of biomass removal. Although whole-tree harvesting does not fully use the nonmerchantable biomass available, it indicates the likely direction and magnitude of impacts that can occur through energy-wood harvesting compared with less-intensive conventional harvesting and to dynamics associated with various natural disturbances. The intent of this comparison is to gauge the degree of departure of energy-wood harvesting from less intensive conventional harvesting. The review of the literature found a gradient of increasing departure in residual structural conditions that remained in the forest when conventional and whole-tree harvesting was compared with stand-replacing natural disturbance. Important stand- and landscape-level processes were related to these structural conditions. The consequence of this departure may be especially potent because future energy-wood harvests may more completely use a greater range of forest biomass at potentially shortened rotations, creating a great need for research that explores the largely unknown scale of disturbance that may apply to our forest ecosystems.

Berger, Alaina L.; Palik, Brian; D'Amato, Anthony W.; Fraver, Shawn; Bradford, John B.; Nislow, Keith; King, David; Brooks, Robert T.

2013-01-01

319

Prototype implementation of ambient RF energy harvesting wireless sensor networks

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

320

Piezoelectric Energy Harvesting with a Clamped Circular Plate: Analysis

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

321

NASA Astrophysics Data System (ADS)

Ambient vibrations are major source of wasted energy, exploiting properly such vibration can be converted to valuable energy and harvested to power up devices, i.e. electronic devices. Accordingly, energy harvesting using smart structures with active piezoelectric ceramics has gained wide interest over the past few years as a method for converting such wasted energy. This paper provides numerical and experimental analysis of piezoelectric fiber based composites for energy harvesting applications proposing a multi-scale modeling approach coupled with experimental verification. The multi-scale approach suggested to predict the behavior of piezoelectric fiber-based composites use micromechanical model based on Transformation Field Analysis (TFA) to calculate the overall material properties of electrically active composite structure. Capitalizing on the calculated properties, single-phase analysis of a homogeneous structure is conducted using finite element method. The experimental work approach involves running dynamic tests on piezoelectric fiber-based composites to simulate mechanical vibrations experienced by a subway train floor tiles. Experimental results agree well with the numerical results both for static and dynamic tests.

El-Etriby, Ahmed E.; Abdel-Meguid, Mohamed E.; Hatem, Tarek M.; Bahei-El-Din, Yehia A.

2014-03-01

322

MEMS based pyroelectric thermal energy harvester

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

323

Analog Microcontroller Model for an Energy Harvesting Round Counter.

National Technical Information Service (NTIS)

An energy harvesting electronic round counter has been developed that uses piezoelectric transducers mounted on the gun to generate electrical energy in response to the strain associated with each fired round. These transducers produce limited energy, so ...

M. Doxbeck M. Johnson S. L. Makowiec

2012-01-01

324

Vibrational energy transfer in fluids

NASA Astrophysics Data System (ADS)

A review of several of the available theories of vibrational energy transfer (VET) in the gas and liquid phases is presented. First the classical theory of gas phase VET mainly due to Landau and Teller, to Jackson and Mott and to Zener is developed in some detail. Next the Schwartz-Slawsky-Herzfeld theory, a framework for analysing VET data based on the classical theory, is outlined. Experimental tests of the classical theory and theoretical critiques of its assumptions are then described. Next a brief review of the modern ab-initio quantum approach to gas phase VET rates, taking as an example the work of Banks, Clary and Werner, is given. Theories of VET at elevated densities are then discussed. The isolated binary collision model is reviewed and a new molecular approach to the density, temperature and isotope dependences of vibrational energy relaxation rates, due to Adelman and co-workers, is outlined.

Miller, David W.; Adelman, Steven A.

325

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

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

326

Resource management for fading wireless channels with energy harvesting nodes

Wireless systems comprised of rechargeable nodes have a significantly prolonged lifetime and are sustainable. A distinct characteristic of these systems is the fact that the nodes can harvest energy throughout the duration in which communication takes place. As such, transmission policies of the nodes need to adapt to these harvested energy arrivals. In this paper, we consider optimization of the

Omur Ozel; Kaya Tutuncuoglu; Jing Yang; Sennur Ulukus; Aylin Yener

2011-01-01

327

Energy Harvesting for Structural Health Monitoring Sensor Networks

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

328

Energy harvesting for human wearable and implantable bio-sensors.

There are clear trade-offs between functionality, battery lifetime and battery volume for wearable and implantable wireless-biosensors which energy harvesting devices may be able to overcome. Reliable energy harvesting has now become a reality for machine condition monitoring and is finding applications in chemical process plants, refineries and water treatment works. However, practical miniature devices that can harvest sufficient energy from the human body to power a wireless bio-sensor are still in their infancy. This paper reviews the options for human energy harvesting in order to determine power availability for harvester-powered body sensor networks. The main competing technologies for energy harvesting from the human body are inertial kinetic energy harvesting devices and thermoelectric devices. These devices are advantageous to some other types as they can be hermetically sealed. In this paper the fundamental limit to the power output of these devices is compared as a function of generator volume when attached to a human whilst walking and running. It is shown that the kinetic energy devices have the highest fundamental power limits in both cases. However, when a comparison is made between the devices using device effectivenesses figures from previously demonstrated prototypes presented in the literature, the thermal device is competitive with the kinetic energy harvesting device when the subject is running and achieves the highest power density when the subject is walking. PMID:21097254

Mitcheson, Paul D

2010-01-01

329

Cooperative energy harvesting for long-endurance autonomous vehicle teams

This paper considers the exploitation of energy harvesting technologies for teams of Autonomous Vehicles (AVs). Traditionally, the optimisation of information gathering tasks such as searching for and tracking new objects, and platform level power management, are only integrated at a mission-management level. In order to truly exploit new energy harvesting technologies which are emerging in both the commercial and military

S. F. Page; J. D. Rogers; K. May; D. R. Myatt; D. Hickman; M. I. Smith

2010-01-01

330

Analysis and design principles for shear-mode piezoelectric energy harvesting with ZnO nanoribbons

NASA Astrophysics Data System (ADS)

A comprehensive theory addresses the potential for nanoscale energy harvesting with an array of vertically aligned zinc oxide (ZnO) nanoribbons. Through shear-mode piezoelectric coupling, the nanoribbons are capable of generating electricity from elastic deformations induced by sliding friction or mechanical vibration. In contrast to current ZnO nanowire generators, nanoribbons exhibit a unique combination of geometry and poling orientation that eliminates the need for a nanostructured cathode and allows electrodes to be permanently bonded to the array. The theory incorporates principles and design constraints from solid mechanics, electrostatics, piezoelectricity, vibration dynamics, circuit theory, and tribology. The accuracy of the approximate algebraic solutions is evaluated with finite element modeling. For geometries and operation modes of interest, the electrical power output and conversion ratio from mechanical power input are limited to ~ 10 nW mm - 3 and 1000:1, respectively. While modest, such numbers provide a proper perspective on the potential for nanopiezoelectric energy harvesting.

Majidi, C.; Haataja, M.; Srolovitz, D. J.

2010-05-01

331

NASA Astrophysics Data System (ADS)

Optimized synchronous electric charge extraction (OSECE) interface is a load weakly-dependant circuit, which is a favorable characteristic for piezoelectric wideband vibration energy harvesting. However, it introduces synchronous switches that need to be self-powered in a stand-alone system. This paper presents the design and experimental testing of two self-powered approaches for the OSECE technique. One is made of electronic switches driven by analog peak detector circuits; the other uses mechanical switches directly controlled by the ambient vibrations. Finally, advantages and drawbacks of the two approaches will be compared and discussed.

Wu, Yipeng; Badel, Adrien; Formosa, Fabien; Liu, Weiqun; Agbossou, Amen

2013-12-01

332

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

333

Wideband capacitive energy harvester based on mechanical frequency-up conversion

A novel mechanical frequency-up convertor for energy harvesting using low frequency ambient vibration based on overlapping capacitive comb has been proposed in this paper. Centrally clamped bistable beam is used to frequency-up conversion which is similar to pre-buckled structure and makes a large acceleration to induce initial displacement. We have achieved more average power from the proposed system by excitation

Salar Chamanian; Reza Pakdaman Zangabad; Payam Zarbakhsh; Manouchehr Bahrami; Mohamad Khodaei

2012-01-01

334

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

335

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

336

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

337

Resistor Emulation Approach to Low-Power Energy Harvesting

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

338

NASA Astrophysics Data System (ADS)

Piezoelectric materials are just now, within the last decade, coming into their own as a commercial material. Capable of converting energy from the mechanical domain to the electrical domain; piezos are ideal sensors, vibration dampers, energy harvesters, and actuators. Frequency rectification, or the conversion of small, high frequency piezoelectric vibrations into useful low frequency actuation, is required to obtain widespread industrial use of piezoelectric devices. This work examines three manifestations of piezoelectric frequency rectification: energy harvesting, a hydraulic motor, and friction based commercial-off-the-shelf motors. An energy harvesting device is developed, manufactured, and tested in this work, resulting in the development of a high Energy Density (J/m 3), high Power Density (W/m3) energy harvester. The device is shown to have an Energy Density nearly twice that of a similar conventional energy harvesting device. The result of this work is the development of an energy harvesting system that generates more energy in a given volume of piezoelectric material, opening the possibility of miniaturization of energy harvesting devices. Also presented is an effort to integrate a high frequency, high flow rate micromachined valve array into a PiezoHydraulic Pump (PHP), enabling resonant operation of the PHP. Currently, the device is limited by the resonant frequency of the proprietary passive check valves. The PHP is fully characterized, and the microvalve array is tested to determine its resonant frequency in a fluid medium. The valve testing resulted in a resonant frequency of 6.9 kHz, slightly lower than the target operating frequency of 10 kHz. Finally, the results of an examination of frequency rectification as applied to COTS piezoelectric motors are presented. Currently, motors are almost universally characterized based upon their available mechanical power. A better comparison is one based upon the actual Energy Density of the piezoelectric material utilized in the motor compared to the theoretical maximum Energy Density under the motor operating conditions (i.e., frequency, applied electric field). The result of this work is a more descriptive metric to evaluate piezoelectric motors that provides information on the effectiveness of the motor drive train; that is, how effectively the motion of the piezoelectric is transferred to the outside world.

Kuroda, Kazuaki; the LCGT Collaboration

339

Vibrational energy relaxation of large-amplitude vibrations in liquids

NASA Astrophysics Data System (ADS)

Given the limited intermolecular spaces available in dense liquids, the large amplitudes of highly excited, low frequency vibrational modes pose an interesting dilemma for large molecules in solution. We carry out molecular dynamics calculations of the lowest frequency (``warping'') mode of perylene dissolved in liquid argon, and demonstrate that vibrational excitation of this mode should cause identifiable changes in local solvation shell structure. But while the same kinds of solvent structural rearrangements can cause the non-equilibrium relaxation dynamics of highly excited diatomic rotors in liquids to differ substantially from equilibrium dynamics, our simulations also indicate that the non-equilibrium vibrational energy relaxation of large-amplitude vibrational overtones in liquids should show no such deviations from linear response. This observation seems to be a generic feature of large-moment-arm vibrational degrees of freedom and is therefore probably not specific to our choice of model system: The lowest frequency (largest amplitude) cases probably dissipate energy too quickly and the higher frequency (more slowly relaxing) cases most likely have solvent displacements too small to generate significant nonlinearities in simple nonpolar solvents. Vibrational kinetic energy relaxation, in particular, seems to be especially and surprisingly linear.

Zhang, Baofeng; Stratt, Richard M.

2012-07-01

340

Piezoelectric Energy Harvester for Batteryless Switch Devices

NASA Astrophysics Data System (ADS)

This study investigated a piezoelectric energy-harvesting system for a mechanical switch device. Piezoelectric ceramics of 0.4Pb(Mg1/3Nb2/3)O3--0.25PbZrO3--0.35PbTiO3 were prepared by using a conventional solid-state reaction method. Li2O, Bi2O3, and CuO additions were used as sintering aids to develop piezoelectric ceramics for low-temperature sintering. Multilayer piezoelectric ceramics with 10× 10× 3 mm3 sizes and with Ag--Pd inner electrodes were manufactured by using the conventional tape-casting method with the prepared powder. A prototype of a piezoelectric batteryless switch device using the multilayer ceramics was produced. It showed an output peak-to-peak voltage of 3.8 V and an output power per strike of 18 ?W. The performance of the device was good enough for practical use.

Kim, Min-Soo; Lee, Sung-Chan; Kim, Sin-Woong; Jeong, Soon-Jong; Kim, In-Sung; Song, Jaesung

2013-10-01

341

Piezoelectric and electromagnetic respiratory effort energy harvesters.

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

2013-01-01

342

NASA Astrophysics Data System (ADS)

Conventional thermoacoustic-piezoelectric (TAP) harvesters convert thermal energy, such as solar or waste heat energy, directly into electrical energy without the need for any moving components. The input thermal energy generates a steep temperature gradient along a porous medium. At a critical threshold of the temperature gradient, self-sustained acoustic waves are developed inside an acoustic resonator. The associated pressure fluctuations impinge on a piezoelectric diaphragm, placed at the end of the resonator. In this study, the TAP harvester is coupled with an auxiliary elastic structure in the form of a simple spring–mass system to amplify the strain experienced by the piezoelectric element. The auxiliary structure is referred to as a dynamic magnifier and has been shown in different areas to significantly amplify the deflection of vibrating structures. A comprehensive model of the dynamically magnified thermoacoustic-piezoelectric (DMTAP) harvester has been developed that includes equations of motions of the system?s mechanical components, the harvested voltage, the mechanical impedance of the coupled structure at the resonator end and the equations necessary to compute the self-excited frequencies of oscillations inside the acoustic resonator. Theoretical results confirmed that significant amplification of the harvested power is feasible if the magnifier?s parameters are properly chosen. The performance characteristics of experimental prototypes of a thermoacoustic-piezoelectric resonator with and without the magnifier are examined. The obtained experimental findings are validated against the theoretical results. Dynamic magnifiers serve as a novel approach to enhance the effectiveness of thermoacoustic energy harvested from waste heat by increasing the efficiency of their harvesting components.

Nouh, M.; Aldraihem, O.; Baz, A.

2014-07-01

343

Hybrid nanogenerator for concurrently harvesting biomechanical and biochemical energy.

Harvesting energy from multiple sources available in our personal and daily environments is highly desirable, not only for powering personal electronics, but also for future implantable sensor-transmitter devices for biomedical and healthcare applications. Here we present a hybrid energy scavenging device for potential in vivo applications. The hybrid device consists of a piezoelectric poly(vinylidene fluoride) nanofiber nanogenerator for harvesting mechanical energy, such as from breathing or from the beat of a heart, and a flexible enzymatic biofuel cell for harvesting the biochemical (glucose/O2) energy in biofluid, which are two types of energy available in vivo. The two energy harvesting approaches can work simultaneously or individually, thereby boosting output and lifetime. Using the hybrid device, we demonstrate a "self-powered" nanosystem by powering a ZnO nanowire UV light sensor. PMID:20507155

Hansen, Benjamin J; Liu, Ying; Yang, Rusen; Wang, Zhong Lin

2010-07-27

344

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

345

NASA Astrophysics Data System (ADS)

A kind of hybrid device for acoustic noise reduction and vibration energy harvesting based on the silicon microperforated panel (MPP) resonant structure is investigated in the article. The critical parts of the device include MPP and energy harvesting membranes. They are all fabricated by means of silicon micro-electro-mechanical systems (MEMS) technology. The silicon MPP has dense and accurate micro-holes. This noise reduction structure has the advantages of wide band and higher absorption coefficients. The vibration energy harvesting part is formed by square piezoelectric membranes arranged in rows. ZnO material is used as it has a good compatibility with the fabrication process. The MPP, piezoelectric membranes, and metal bracket are assembled into a hybrid device with multifunctions. The device exhibits good performances of acoustic noise absorption and acoustic–electric conversion. Its maximum open circuit voltage achieves 69.41 mV.

Wu, Shao-Hua; Du, Li-Dong; Kong, De-Yi; Ping, Hao-Yue; Fang, Zhen; Zhao, Zhan

2014-04-01

346

Optimization of an Electromagnetic Energy Harvesting Device

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

347

Monomorph piezoelectric wideband energy harvester integrated into LTCC

In this paper the first fully LTCC embedded piezoelectric vibration harvester is demonstrated and characterized. Using ordinary LTCC processes a 39mm×39mm×3mm package containing 25mm co-fired PZT discs was made. Three laser cut beams of different lengths provided a 5.4% frequency bandwidth for 3dB attenuation and a power of 32?W at 1g acceleration delivered into a 33.9k? resistive load. The packaged

Maciej Sobocinski; Mikko Leinonen; Jari Juuti; Heli Jantunen

2011-01-01

348

Optimizing energy harvesting parameters using response surface methodology.

Energy harvesting is a process in which energy that would otherwise be wasted is stored and then used to power a system. Due to their unique properties piezoelectric materials are ideal for energy harvesting applications. In this study a pre-stressed piezoelectric composite was pressure loaded dynamically to harvest energy. The objective of this study was to optimize, using piezoelectric diaphragms, relevant parameters that have an effect on the energy harvesting process. Parameters considered were temperature, pressure, resistance and frequency. Response surface methodology was used to develop models to identify optimal parameter ranges and also to predict power conversion capabilities for specific parameter levels. Power densities of approximately 24.27 microW/mm(3) were measured at optimal conditions. The model identified an optimal temperature of 12 degrees C and a pressure of 240 kPa, which are in agreement with experimental results. PMID:19411203

Mane, Poorna; Mossi, Karla; Green, Christopher

2009-03-01

349

A batch process micromachined thermoelectric energy harvester: fabrication and characterization

Micromachined thermopiles are considered as a cost-effective solution for energy harvesters working at a small temperature difference and weak heat flows typical for, e.g., the human body. They can be used for powering autonomous wireless sensor nodes in a body area network. In this paper, a micromachined thermoelectric energy harvester with 6 µm high polycrystalline silicon germanium (poly-SiGe) thermocouples fabricated

J. Su; V. Leonov; M. Goedbloed; Y. van Andel; M. C. de Nooijer; R. Elfrink; Z. Wang; R. J. M. Vullers

2010-01-01

350

NASA Astrophysics Data System (ADS)

This paper presents miniaturized energy harvesters, where the frequency up-conversion technique is used to improve the bandwidth of vibration energy harvesters. The proposed and developed miniature piezoelectric energy harvester utilizes magnetic repulsion forces to achieve non-contact frequency up-conversion, thereby avoiding mechanical collision and wear for long-term working durability. A pair of piezoelectric resonant cantilevers is micro-fabricated to generate electric power. A simplified model involving linear oscillators and magnetic interaction is deployed to demonstrate the feasibility of the device design. A bench-top harvester has been fabricated and characterized, resulting in average power generation of over 10 µW within a broad frequency range of 10-22 Hz under 1g acceleration.

Tang, Q. C.; Yang, Y. L.; Li, Xinxin

2011-12-01

351

NASA Astrophysics Data System (ADS)

In some energy harvesting systems, the maximum displacement of the seismic mass is limited due to the physical constraints of the device. This is especially the case where energy is harvested from a vibration source with large oscillation amplitude (e.g., marine environment). For the design of inertial systems, the maximum permissible displacement of the mass is a limiting condition. In this paper the maximum output power and the corresponding efficiency of linear and rotational electromagnetic energy harvesting systems with a constrained range of motion are investigated. A unified form of output power and efficiency is presented to compare the performance of constrained linear and rotational systems. It is found that rotational energy harvesting systems have a greater capability in transferring energy to the load resistance than linear directly coupled systems, due to the presence of an extra design variable, namely the ball screw lead. Also, in this paper it is shown that for a defined environmental condition and a given proof mass with constrained throw, the amount of power delivered to the electrical load by a rotational system can be higher than the amount delivered by a linear system. The criterion that guarantees this favourable design has been obtained.

Hendijanizadeh, M.; Sharkh, S. M.; Elliott, S. J.; Moshrefi-Torbati, M.

2013-12-01

352

Energy management of multi-component power harvesting systems

NASA Astrophysics Data System (ADS)

Recent efforts in power harvesting systems have concentrated primarily on the optimization of isolated energy conversion techniques, such as piezoelectric, electromagnetic, solar, or thermal generators, but have focused less on combining different energy transducer types and have placed less emphasis on storing the converted energy for use by other devices. The purpose of this work is to analyze and present an integrated piezoelectric and electromagnetic power harvesting system utilizing existing technology for energy management and storage. Primary emphasis is on the analysis of the combination of existing, or readily obtainable, energy conversion techniques, operating as a single system, and the energy conversion efficiency of the alternating to direct current management, or storage, circuit.

MacCurdy, Robert B.; Reissman, Timothy; Garcia, Ephrahim

2008-05-01

353

NASA Astrophysics Data System (ADS)

This work investigates a vibration-based energy harvesting system composed of two oscillators coupled with essential (nonlinearizable) stiffness nonlinearity and subject to impulsive loading of the mechanical component. The oscillators in the system consist of one grounded, weakly damped linear oscillator mass (primary system), which is coupled to a second light-weight, weakly damped oscillating mass attachment (the harvesting element) through a piezoelastic cable. Due to geometric/kinematic mechanical effects the piezoelastic cable generates a nonlinearizable cubic stiffness nonlinearity, whereas electromechanical coupling simply sees a resistive load. Under single and repeated impulsive inputs the transient damped dynamics of this system exhibit transient resonance captures (TRCs) causing high-frequency 'bursts' or instabilities in the response of the harvesting element. In turn, these high-frequency dynamic instabilities result in strong and sustained energy transfers from the directly excited primary system to the lightweight harvester, which, through the piezoelastic element, are harvested by the electrical component of the system or, in the present case, dissipated across a resistive element in the circuit. The primary goal of this work is to demonstrate the efficacy of employing this type of high-frequency dynamic instability to achieve enhanced nonlinear vibration energy harvesting under impulsive excitations.

Remick, Kevin; Joo, Han Kyul; McFarland, D. Michael; Sapsis, Themistoklis P.; Bergman, Lawrence; Quinn, D. Dane; Vakakis, Alexander

2014-07-01

354

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

355

A shoe-embedded piezoelectric energy harvester for wearable sensors.

Harvesting mechanical energy from human motion is an attractive approach for obtaining clean and sustainable electric energy to power wearable sensors, which are widely used for health monitoring, activity recognition, gait analysis and so on. This paper studies a piezoelectric energy harvester for the parasitic mechanical energy in shoes originated from human motion. The harvester is based on a specially designed sandwich structure with a thin thickness, which makes it readily compatible with a shoe. Besides, consideration is given to both high performance and excellent durability. The harvester provides an average output power of 1 mW during a walk at a frequency of roughly 1 Hz. Furthermore, a direct current (DC) power supply is built through integrating the harvester with a power management circuit. The DC power supply is tested by driving a simulated wireless transmitter, which can be activated once every 2-3 steps with an active period lasting 5 ms and a mean power of 50 mW. This work demonstrates the feasibility of applying piezoelectric energy harvesters to power wearable sensors. PMID:25019634

Zhao, Jingjing; You, Zheng

2014-01-01

356

Energy scavenging from environmental vibration.

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

357

Development of MEMS based pyroelectric thermal energy harvesters

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

358

A technique for giant mechanical energy harvesting using ferroelectric/antiferroelectric materials

NASA Astrophysics Data System (ADS)

Ferroelectric materials are widely employed as piezoelectric materials for numerous energy harvesting systems. However, conventional systems employing direct piezoelectric effect for vibrational energy harvesting suffer from low energy density and high actuation frequency requirements. In this regards, the authors have presented a new technique for giant mechanical energy conversion using ferroelectric/antiferroelectric materials in a cyclic manner. The proposed method will allow for large electromechanical energy conversion in a wide frequency domain. The cycle was simulated for polycrystalline Pb0.99Nb0.02[(Zr0.57Sn0.43)0.94Ti0.06]0.98O3 (PNZST) antiferroelectric bulk ceramic. It was observed that for cycle parameters of (20 to 60 kV·cm-1 and 0 to 250 MPa), a harvesting energy density of 689 kJ·m-3·cycle-1 can be obtained for uniaxial compressive stress. While an energy density of 919 kJ·m-3·cycle-1 can be obtained for radial compressive stress with cycle parameters of (20 to 60 kV·cm-1 and 0 to 360 MPa). This is several orders of magnitude larger than the highest energy density reported in the literature.

Patel, Satyanarayan; Chauhan, Aditya; Vaish, Rahul

2014-02-01

359

Harvesting Energy from the Counterbalancing (Weaving) Movement in Bicycle Riding

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.

Yang, Yoonseok; Yeo, Jeongjin; Priya, Shashank

2012-01-01

360

Evaluation of motions and actuation methods for biomechanical energy harvesting

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

361

Indoor solar energy harvesting for sensor network router nodes

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

362

Hybrid energy harvester based on nanopillar solar cells and PVDF nanogenerator.

A tandem device which integrates a PVDF nanogenerator and silicon (Si) nanopillar solar cell is fabricated. The Si nanopillar solar cell was fabricated using a mask-free plasma etching technique and annealing process. The PVDF nanogenerator was stacked on top of the Si nanopillar solar cell using a spinning method. The optical properties and the device performance of nanowire solar cells have been characterized, and the dependence of device performance versus annealing time or method has been investigated. Furthermore, the PVDF nanogenerator was operated with a 100 dB sound wave and a 0.8 V peak to peak output voltage was generated. This tandem device can successfully harvest energy from both sound vibration and solar light, demonstrating its strong potential as a future ubiquitous energy harvester. PMID:23558434

Lee, Dae-Yeong; Kim, Hyunjin; Li, Hua-Min; Jang, A-Rang; Lim, Yeong-Dae; Cha, Seung Nam; Park, Young Jun; Kang, Dae Joon; Yoo, Won Jong

2013-05-01

363

Ultra-wide frequency broadening mechanism for micro-scale electromagnetic energy harvester

NASA Astrophysics Data System (ADS)

This work proposed a hybrid frequency broadening (HFB) mechanism in micro-scale for vibration energy harvesting with ultra-wide bandwidth. A strong HFB behavior is induced by the Duffing stiffening of the clamped-clamped beam stretching and further stimulated continuously by three distributed resonances including out-of-plane mode I at 62.9 Hz, torsion mode II at 82.1 Hz, and twist mode III at 150 Hz. At the acceleration of 1.0g, the microfabricated device with a small area of 6 × 6 mm2 is able to broaden the operating bandwidth from 62.9 Hz to be as wide as 383.7 Hz. This design methodology can be implemented for efficient electromagnetic energy harvesting.

Liu, Huicong; How Koh, Kah; Lee, Chengkuo

2014-02-01

364

Analysis of an energy harvesting piezoelectric beam with energy storage circuit

NASA Astrophysics Data System (ADS)

Accurate (distributed-parameter) models of energy harvesting piezoelectric beams have recently been presented and experimentally validated. However, these studies were limited in their practical significance since the external electrical load was assumed to be a simple linear impedance (resistor or capacitor), without any means of energy storage. This paper presents and validates experimentally a mathematical model of a base-excited piezoelectric cantilever connected across an energy storage circuit comprising a diode in series with a capacitor. The resulting half-wave AC-DC rectification enables the capacitor to retain a part of the harvested energy (i.e. accumulate a mean voltage). The Euler-Bernoulli beam model with piezoelectric coupling is used. The resulting wave equation is transformed into modal space using the analytical modal analysis method (AMAM). The Shockley diode equation is used to model the current. The resulting nonlinear system of equations is solved for a prescribed base motion input using a numerical integration routine. The analysis of the same cantilever connected across an unrectified capacitor is also performed for comparative purposes. Theoretical studies show that, for the case of the rectified capacitor, as well as the unrectified capacitor, the energy harvesting effect does not have a dampening effect on the steady-state vibration. However, whereas the resonance frequency of the unrectified system is a function of the load, the resonance frequency of the rectified system is fixed at a value that is very close to the open circuit resonance frequency of the unrectified system. The theoretical findings are validated by the experimental results.

Dalzell, P.; Bonello, P.

2012-10-01

365

Large-scale self-tuning solid-state kinetic energy harvester

NASA Astrophysics Data System (ADS)

In recent years there has been a strong emphasis on kinetic (vibration) energy harvesting using smart structure technology. This emphasis has been driven in large part by industry demand for powering sensors and wireless telemetry of sensor data in places into which running power and data cables is difficult or impossible. Common examples are helicopter drive shafts and other rotating equipment. In many instances, available space in these locations is highly limited, resulting in a trend for miniaturization of kinetic energy harvesters. While in some cases size limitations are dominant, in other cases large and even very large harvesters are possible and even desirable since they may produce significantly more power. Examples of large-scale energy harvesting include geomatics, which is the discipline of gathering, storing, processing, and delivering spatially referenced information on vast scales. Geomatics relies on suites of various sensors and imaging devices such as meteorological sensors, seismographs, high-resolution cameras, and LiDAR's. These devices may be stationed for prolonged periods of time in remote and poorly accessible areas and are required to operate continuously over prolonged periods of time. In other cases, sensing and imaging equipment may be mounted on land, sea, or airborne platforms and expected to operate for many hours on its own power. Providing power to this equipment constitutes a technological challenge. Other cases may include commercial buildings, unmanned powered gliders and more. Large scale kinetic energy harvesting thus constitutes a paradigm shift in the approach to kinetic energy harvesting as a whole and as often happens it poses its own unique technological challenges. Primarily these challenges fall into two categories: the cost-effective manufacturing of large and very large scale transducing elements based on smart structure technology and the continuous optimization (tuning) of these transducers for various operating conditions. Current research proposes the simultaneous solution of both of the aforementioned challenges via the use of specialized technology for the incorporation of large numbers of piezoelectric transducers into standard printed circuit boards and the continuous control of structural resonance via the application of adaptive compressive stress. Used together, these technologies allow for fully scalable and tunable kinetic energy harvesting. Since the design is modular in nature and a typical size of a single module can easily reach dimensions of 60 by 40 centimeters, there is virtually no upper limit on the size of the harvester other than the limits that derive from its specific applications and placement. The use of compressive forces rather than the commonly used non-structural mass for the tuning of the harvester frequency to the disturbing frequency allows for continuous adaptive tuning while at the same time avoiding the undesirable vibration damping effects of non-structural mass. A proof of concept large-scale harvester capable of manual compressive force tuning was built as part of the current study and preliminary tests were conducted. The tests validate the proposed approach showing power generation on the order of 10 mW at disturbing frequencies between 10 and 100 Hz, with RMS voltages reaching over 20 volts and RMS currents over 2 mA, with proven potential for 50 mW with over 100 VAC and 10 mA for a transducing panel 20 by 10 cm. The results also validate the tuning via compressive force approach, showing strong dependence of energy harvesting efficiency on the compressive force applied to the transducing panel.

Pletner, Baruch; Swan, Lukas; Wettels, Nicholas; Joseph, Alain

2012-03-01

366

Wideband energy harvesting for piezoelectric devices with linear resonant behavior.

In this paper, an active energy harvesting technique for a spring-mass-damper mechanical resonator with piezoelectric electromechanical coupling is investigated. This technique applies a square-wave voltage to the terminals of the device at the same frequency as the mechanical excitation. By controlling the magnitude and phase angle of this voltage, an effective impedance matching can be achieved which maximizes the amount of power extracted from the device. Theoretically, the harvested power can be the maximum possible value, even at off-resonance frequencies. However, in actual implementation, the efficiency of the power electronic circuit limits the amount of power harvested. A power electronic full-bridge converter is built to implement the technique. Experimental results show that the active technique can increase the effective bandwidth by a factor of more than 2, and harvests significantly higher power than rectifier-based circuits at off-resonance frequencies. PMID:21768014

Luo, Cheng; Hofmann, Heath F

2011-07-01

367

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

368

Magnetic flux concentration methods for magnetic energy harvesting module

NASA Astrophysics Data System (ADS)

This paper presents magnetic flux concentration methods for magnetic energy harvesting module. The purpose of this study is to harvest 1 mW energy with a Brooks coil 2 cm in diameter from environmental magnetic field at 60 Hz. Because the harvesting power is proportional to the square of the magnetic flux density, we consider the use of a magnetic flux concentration coil and a magnetic core. The magnetic flux concentration coil consists of an aircore Brooks coil and a resonant capacitor. When a uniform magnetic field crossed the coil, the magnetic flux distribution around the coil was changed. It is found that the magnetic field in an area is concentrated larger than 20 times compared with the uniform magnetic field. Compared with the aircore coil, our designed magnetic core makes the harvested energy tenfold. According to ICNIRP2010 guideline, the acceptable level of magnetic field is 0.2 mT in the frequency range between 25 Hz and 400 Hz. Without the two magnetic flux concentration methods, the corresponding energy is limited to 1 µW. In contrast, our experimental results successfully demonstrate energy harvesting of 1 mW from a magnetic field of 0.03 mT at 60 Hz.

Tashiro, Kunihisa; Hattori, Gen-ya; Wakiwaka, Hiroyuki

2013-01-01

369

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

370

A Piezoelectric PZT Ceramic Mulitlayer Stack for Energy Harvesting Under Dynamic Forces

NASA Technical Reports Server (NTRS)

Piezoelectric energy harvesting transducers (PEHTs) are commonly used in motion/vibration energy scavenging devices. To date, most researchers have focused on energy harvesting at narrow bandwidths around the mechanical resonance frequency, and most piezoelectric harvesting devices reported in the literature have very low effective piezoelectric coefficient (d(sub eff)) (< 10(exp 4) pC/N). For instance, more than 80% of PEHT related papers are on transverse "31" mode cantilever beam type PEHTs (CBPEHTs) having piezoelectric coefficients of about 100 pC/N. The level of harvested electrical power for CBPEHTs is on the order of microW even at resonance mode. In order to harvest more electrical energy across broader bandwidth, high effective piezoelectric coefficient structures are needed. In this study, we investigate a "33" longitudinal mode, piezoelectric PZT ceramic multilayer stack (PZT-Stack) with high effective piezoelectric coefficient for high-performance PEHTs. The PZT-Stack is composed of 300 layers of 0.1 mm thick PZT plates, with overall dimensions of 32.4 mm X 7.0 mm X 7.0 mm. Experiments were carried out with dynamic forces in a broad bandwidth ranging from 0.5 Hz to 25 kHz. The measured results show that the effective piezoelectric coefficient of the PZT-stack is about 1 X 10(exp 5) pC/N at off-resonance frequencies and 1.39 X 10(exp 6) pC/N at resonance, which is order of magnitude larger than that of traditional PEHTs. The effective piezoelectric coefficients (d(sub eff)) do not change significantly with applied dynamic forces having root mean square (RMS) values ranging from 1 N to 40 N. In resonance mode, 231 mW of electrical power was harvested at 2479 Hz with a dynamic force of 11.6 N(sub rms), and 7.6 mW of electrical power was generated at a frequency of 2114 Hz with 1 N(sub rms) dynamic force. In off-resonance mode, an electrical power of 18.7 mW was obtained at 680 Hz with a 40 N(sub rms) dynamic force. A theoretical model of energy harvesting for the PZT-Stack is established. The modeled results matched well with experimental measurements. This study demonstrated that high effective piezoelectric coefficient structures enable PEHTs to harvest more electrical energy from mechanical vibrations or motions, suggesting an effective design for high-performance low-footprint PEHTs with potential applications in military, aerospace, and portable electronics. In addition, this study provides a route for using piezoelectric multilayer stacks for active or semi-active adaptive control to damp, harvest or transform unwanted dynamic vibrations into useful electrical energy.

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

2011-01-01

371

Thermoelectric energy harvesting as a wireless sensor node power source

NASA Astrophysics Data System (ADS)

Size and power requirements of wireless sensor nodes are gradually decreasing and this has allowed data collection across a range of spatial and temporal ranges. These nodes have power requirements that often necessitate batteries as an energy source. As the power requirements decrease for these sensors, alternative energy sources become more attractive. One such technology is thermal energy harvesting. Thermal energy harvesting requires a differential temperature between a heat source and a cool sink. As heat energy flows from source to the sink, energy can be harvested and utilized to power sensor nodes. By exploiting the temperature difference between a sun-warmed plate and a heat sink immersed in water, electrical energy can be harvested. The proposed concept utilizes a thermoelectric device to convert solar energy into electrical power. Initial experiments were carried out at the CSIRO Energy Centre for a variety of winter time intervals in 2009, with peak power outputs in the order of 50mW. Results indicate such a system could power a wireless sensor node continuously at ocean, lake and river water interfaces. We are presently in the process of evaluating the concept by powering a CSIRO FleckTM wireless node to transmit water temperature and battery voltage data.

Knight, C.; Davidson, J.

2010-03-01

372

The recently introduced triboelectric nanogenerator (TENG) and the traditional electromagnetic induction generator (EMIG) are coherently integrated in one structure for energy harvesting and vibration sensing/isolation. The suspended structure is based on two oppositely oriented magnets that are enclosed by hollow cubes surrounded with coils, which oscillates in response to external disturbance and harvests mechanical energy simultaneously from triboelectrification and electromagnetic induction. It extends the previous definition of hybrid cell to harvest the same type of energy with multiple approaches. Both the sliding-mode TENG and contact-mode TENG can be achieved in the same structure. In order to make the TENG and EMIG work together, transformers are used to match the output impedance between these two power sources with very different characteristics. The maximum output power of 7.7 and 1.9 mW on the same load of 5 k? was obtained for the TENG and EMIG, respectively, after impedance matching. Benefiting from the rational design, the output signal from the TENG and the EMIG are in phase. They can be added up directly to get an output voltage of 4.6 V and an output current of 2.2 mA in parallel connection. A power management circuit was connected to the hybrid cell, and a regulated voltage of 3.3 V with constant current was achieved. For the first time, a logic operation was carried out on a half-adder circuit by using the hybrid cell working as both the power source and the input digit signals. We also demonstrated that the hybrid cell can serve as a vibration isolator. Further applications as vibration dampers, triggers, and sensors are all promising. PMID:24924185

Hu, Youfan; Yang, Jin; Niu, Simiao; Wu, Wenzhuo; Wang, Zhong Lin

2014-07-22

373

In this paper, we study energy harvesting from the beating of a biomimetic fish tail using ionic polymer-metal composites. The design of the biomimetic tail is based on carangiform swimmers and is specifically inspired by the morphology of the heterocercal tail of thresher sharks. The tail is constituted of a soft silicone matrix molded in the form of the heterocercal tail and reinforced by a steel beam of rectangular cross section. We propose a modeling framework for the underwater vibration of the biomimetic tail, wherein the tail is assimilated to a cantilever beam with rectangular cross section and heterogeneous physical properties. We focus on base excitation in the form of a superimposed rotation about a fixed axis and we consider the regime of moderately large-amplitude vibrations. In this context, the effect of the encompassing fluid is described through a hydrodynamic function, which accounts for inertial, viscous and convective phenomena. The model is validated through experiments in which the base excitation is systematically varied and the motion of selected points on the biomimetic tail tracked in time. The feasibility of harvesting energy from an ionic polymer-metal composite attached to the vibrating structure is experimentally and theoretically assessed. The response of the transducer is described using a black-box model, where the voltage output is controlled by the rate of change of the mean curvature. Experiments are performed to elucidate the impact of the shunting resistance, the frequency of the base excitation and the placement of the ionic polymer-metal composite on energy harvesting from the considered biomimetic tail. PMID:23793023

Cha, Youngsu; Verotti, Matteo; Walcott, Horace; Peterson, Sean D; Porfiri, Maurizio

2013-09-01

374

Real-time scheduling for energy harvesting sensor nodes

Abstract , Energy harvesting has recently emerged as a feasible option to increase the operating 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

Clemens Moser; Davide Brunelli; Lothar Thiele; Luca Benini

2007-01-01

375

Analysis of power output for piezoelectric energy harvesting systems

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

376

An Efficient Solar Energy Harvester for Wireless Sensor Nodes

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

377

Human powered MEMS-based energy harvest devices

The lifespan and stability of power supply are the most critical issues for implantable biomedical devices (IMDs). Extracting energy from the ambient sources or human body therefore attracts a lot of attentions for in vivo therapies. Micro-electromechanical systems (MEMSs) based energy harvesters are expected to be one of the potential solutions to supply electrical power to IMDs owing to its

Chung-Yang Sue; Nan-Chyuan Tsai

2012-01-01

378

Nanotechnologies for efficient solar and wind energy harvesting and storage

We describe nanotechnologies used to improve the efficient harvest of energy from the Sun and the wind, and the efficient storage of energy in secondary batteries and ultracapacitors, for use in a variety of applications including smart grids, electric vehicles, and portable electronics. We demonstrate high-quality nanostructured copper indium gallium selenide (CIGS) thin films for photovoltaic (PV) applications. The self-assembly

Louay A. Eldada

2010-01-01

379

A batch process micromachined thermoelectric energy harvester: fabrication and characterization

NASA Astrophysics Data System (ADS)

Micromachined thermopiles are considered as a cost-effective solution for energy harvesters working at a small temperature difference and weak heat flows typical for, e.g., the human body. They can be used for powering autonomous wireless sensor nodes in a body area network. In this paper, a micromachined thermoelectric energy harvester with 6 µm high polycrystalline silicon germanium (poly-SiGe) thermocouples fabricated on a 6 inch wafer is presented. An open circuit voltage of 1.49 V and an output power of 0.4 µW can be generated with 3.5 K temperature difference in a model of a wearable micromachined energy harvester of the discussed design, which has a die size of 1.0 mm × 2.5 mm inside a watch-size generator.

Su, J.; Leonov, V.; Goedbloed, M.; van Andel, Y.; de Nooijer, M. C.; Elfrink, R.; Wang, Z.; Vullers, R. J. M.

2010-10-01

380

Sensorless Estimation and Nonlinear Control of a Rotational Energy Harvester

NASA Astrophysics Data System (ADS)

It is important to perform sensorless monitoring of parameters in energy harvesting devices in order to determine the operating states of the system. However, physical measurements of these parameters is often a challenging task due to the unavailability of access points. This paper presents, as an example application, the design of a nonlinear observer and a nonlinear feedback controller for a rotational energy harvester. A dynamic model of a rotational energy harvester with its power electronic interface is derived and validated. This model is then used to design a nonlinear observer and a nonlinear feedback controller which yield a sensorless closed-loop system. The observer estimates the mechancial quantities from the measured electrical quantities while the control law sustains power generation across a range of source rotation speeds. The proposed scheme is assessed through simulations and experiments.

Nunna, Kameswarie; Toh, Tzern T.; Mitcheson, Paul D.; Astolfi, Alessandro

2013-12-01

381

NASA Astrophysics Data System (ADS)

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 elementary single-degree-of-freedom models to approximate distributed parameter solutions in the sense of Rayleigh-Ritz discretization as well as analytical solution attempts with certain simplifications. Recently, the authors have presented the closed-form analytical solution for a unimorph cantilever under base excitation based on the Euler-Bernoulli beam assumptions. In this paper, the analytical solution is applied to bimorph cantilever configurations with series and parallel connections of piezoceramic layers. The base excitation is assumed to be translation in the transverse direction with a superimposed small rotation. The closed-form steady state response expressions are obtained for harmonic excitations at arbitrary frequencies, which are then reduced to simple but accurate single-mode expressions for modal excitations. The electromechanical frequency response functions (FRFs) that relate the voltage output and vibration response to translational and rotational base accelerations are identified from the multi-mode and single-mode solutions. Experimental validation of the single-mode coupled voltage output and vibration response expressions is presented for a bimorph cantilever with a tip mass. It is observed that the closed-form single-mode FRFs obtained from the analytical solution can successfully predict the coupled system dynamics for a wide range of electrical load resistance. The performance of the bimorph device is analyzed extensively for the short circuit and open circuit resonance frequency excitations and the accuracy of the model is shown in all cases.

Erturk, A.; Inman, D. J.

2009-02-01

382

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

383

An effective multisource energy harvesting system is presented as power supply for wireless sensor nodes (WSNs). The advanced system contains not only an expandable power management module including control of the charging and discharging process of the lithium polymer battery but also an energy harvesting system using the maximum power point tracking (MPPT) circuit with analog driving scheme for the collection of both solar and vibration energy sources. Since the MPPT and the power management module are utilized, the system is able to effectively achieve a low power consumption. Furthermore, a super capacitor is integrated in the system so that current fluctuations of the lithium polymer battery during the charging and discharging processes can be properly reduced. In addition, through a simple analog switch circuit with low power consumption, the proposed system can successfully switch the power supply path according to the ambient energy sources and load power automatically. A practical WSNs platform shows that efficiency of the energy harvesting system can reach about 75-85% through the 24-hour environmental test, which confirms that the proposed system can be used as a long-term continuous power supply for WSNs. PMID:25032233

Li, Hao; Zhang, Gaofei; Ma, Rui; You, Zheng

2014-01-01

384

An effective multisource energy harvesting system is presented as power supply for wireless sensor nodes (WSNs). The advanced system contains not only an expandable power management module including control of the charging and discharging process of the lithium polymer battery but also an energy harvesting system using the maximum power point tracking (MPPT) circuit with analog driving scheme for the collection of both solar and vibration energy sources. Since the MPPT and the power management module are utilized, the system is able to effectively achieve a low power consumption. Furthermore, a super capacitor is integrated in the system so that current fluctuations of the lithium polymer battery during the charging and discharging processes can be properly reduced. In addition, through a simple analog switch circuit with low power consumption, the proposed system can successfully switch the power supply path according to the ambient energy sources and load power automatically. A practical WSNs platform shows that efficiency of the energy harvesting system can reach about 75–85% through the 24-hour environmental test, which confirms that the proposed system can be used as a long-term continuous power supply for WSNs.

Li, Hao; Zhang, Gaofei; Ma, Rui; You, Zheng

2014-01-01

385

NASA Astrophysics Data System (ADS)

Bistable generators have been proposed as potential solutions to the challenge of variable vibration frequencies. In the authors' previous works, a specific BSM (Buckled-Spring-Mass) harvester architecture has been suggested. It presents some properties of interests: simplicity, compactness and wide bandwidth. Using a normalized model of the BSM generator for design and optimization at different scales, this paper presents a new integrated BSM bistable generator design with the OSECE (Optimized Synchronous Electric Charge Extraction) technique which is used for broadband energy harvesting. The experimental results obtained from an initial prototype device show that the BSM generator with the OSECE circuit exhibits better performance for low coupling cases or reverse sweep excitations. This is also confirmed by simulations for the proposed integrated generator. Good applications prospective is expected for the bistable generator with the nonlinear OSECE circuit.

Liu, Weiqun; Badel, Adrien; Formosa, Fabien; Wu, Yipeng; Agbossou, Amen

2013-12-01

386

Harvesting renewable energy from Earth's mid-infrared emissions.

It is possible to harvest energy from Earth's thermal infrared emission into outer space. We calculate the thermodynamic limit for the amount of power available, and as a case study, we plot how this limit varies daily and seasonally in a location in Oklahoma. We discuss two possible ways to make such an emissive energy harvester (EEH): A thermal EEH (analogous to solar thermal power generation) and an optoelectronic EEH (analogous to photovoltaic power generation). For the latter, we propose using an infrared-frequency rectifying antenna, and we discuss its operating principles, efficiency limits, system design considerations, and possible technological implementations. PMID:24591604

Byrnes, Steven J; Blanchard, Romain; Capasso, Federico

2014-03-18

387

Piezoelectric and electrostatic bimetal-based thermal energy harvesters

NASA Astrophysics Data System (ADS)

This paper reports on innovative thermal energy harvesters (TEH) turning heat fluxes into electricity in a two-step conversion, involving (i) a curved bimetallic strip converting thermal gradients into mechanical oscillations, which are then (ii) converted into electricity by a piezoelectric or an electret-based electrostatic transducer. This work mainly focuses on (i) the optimizations of the piezoelectric devices, (ii) a first demonstration of a Wireless Sensor Node powered by our electrostatic transducers, validating the viability of bimetal-based thermal energy harvesters, and (iii) the possibility of future scaled scavengers by a micrometric silicon approach to improve efficiencies and power densities.

Arnaud, A.; Boisseau, S.; Monfray, S.; Puscasu, O.; Despesse, G.; Boughaleb, J.; Sanchez, Y.; Battegay, F.; Fourel, M.; Audran, S.; Boeuf, F.; Delamare, J.; Delepierre, G.; Pitone, G.; Skotnicki, T.

2013-12-01

388

Wireless energy transmission to supplement energy harvesters in sensor network applications

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

389

The effect of polymer fill ratio in pillar structure for piezoelectric energy harvester

NASA Astrophysics Data System (ADS)

One method of energy harvesting is to use piezoelectric devices, which are able to interchange electrical energy and mechanical strain or vibration. This study is to experimentally investigate the behavior of a piezoelectric energy harvester that was constructed with an array of pillar structures made of 0.2(PbMg1/3Nb2/3O3)-0.8(PbZr0.475Ti0.525O3) with polymer fill. Additionally, the aim of this study is to optimize the fill ratio of the composite piezoelectric ceramics and polymer structure. 0.2(PbMg1/3Nb2/3O3)-0.8(PbZr0.475Ti0.525O3) ceramics were employed as piezoelectric ceramic pillars, prepared in a rectangular shape. These piezoelectric ceramic pillars were sintered separately and attached to a bottom metallic electrode with poled states. The optimum ratio of ceramic pillar and elastic polymer ratio will be discussed. Piezoelectric properties will be discussed including the piezoelectric constant, piezoelectric voltage constants, and electromechanical coupling coefficient. We will present how the harvested energy depends on the lead resistor.

Lee, Kyoung-Soo; Shin, Dong-Jin; Chae, Moon-Soon; Koo, Sang-Mo; Ha, Jae-Geun; Koh, Jung-Hyuk; Cho, Kyung-Ho; Seo, Chang-Eui; Jeong, Soon-Jong

2013-07-01

390

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

NASA Astrophysics Data System (ADS)

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 electrical energy is an intensively investigated field. In this domain, it has been shown that the harvested energy can be greatly improved by the use of an original non-linear treatment of the piezoelectric voltage called SSHI (Synchronized Switch Harvesting on Inductor), which consists in intermittently switching the piezoelectric element on a resonant electrical network for a very short time. However, the integration of miniaturized microgenerators with low voltage output (e.g. MEMS microgenerators) has not been widely studied. In the case of low voltage output, the losses introduced by voltage gaps of discrete components such as diodes or transistors can no longer be neglected. Therefore the purpose of this paper is to propose a model that takes into account such losses as well as a new architecture for the SSHI energy harvesting circuit that limits such losses in the harvesting process. While most of the study uses an externally powered microcontroller for the non-linear treatment, this circuit is fully self-powered, thus providing an enhanced autonomous microgenerator. In particular this circuit aims at limiting the effect of non-linear components with a voltage gap such as diodes. It is shown both theoretically and experimentally that the harvested power can be significantly increased using such a circuit. In particular, experimental measurements performed on a cantilever beam show that the circuit allows a 160% increase of the harvested power compared to a standard energy harvesting circuit, while the classical implementation of the SSHI shows an increase of only 100% of the output power in the classical case.

Lallart, Mickaël; Guyomar, Daniel

2008-06-01

391

Energy harvesting from electric power lines employing the Halbach arrays.

This paper proposes non-invasive energy harvesters to scavenge alternating magnetic field energy from electric power lines. The core body of a non-invasive energy harvester is a linear Halbach array, which is mounted on the free end of a piezoelectric cantilever beam. The Halbach array augments the magnetic flux density on the side of the array where the power line is placed and significantly lowers the magnetic field on the other side. Consequently, the magnetic coupling strength is enhanced and more alternating magnetic field energy from the current-carrying power line is converted into electrical energy. An analytical model is developed and the theoretical results verify the experimental results. A power of 566 ?W across a 196 k? resistor is generated from a single wire, and a power of 897 ?W across a 212 k? resistor is produced from a two-wire power cord carrying opposite currents at 10 A. The harvesters employing Halbach arrays for a single wire and a two-wire power cord, respectively, exhibit 3.9 and 3.2 times higher power densities than those of the harvesters employing conventional layouts of magnets. The proposed devices with strong response to the alternating currents are promising to be applied to electricity end-use environment in electric power systems. PMID:24182155

He, Wei; Li, Ping; Wen, Yumei; Zhang, Jitao; Lu, Caijiang; Yang, Aichao

2013-10-01

392

Piezoelectric touch-sensitive flexible hybrid energy harvesting nanoarchitectures.

In this work, we report a flexible hybrid nanoarchitecture that can be utilized as both an energy harvester and a touch sensor on a single platform without any cross-talk problems. Based on the electron transport and piezoelectric properties of a zinc oxide (ZnO) nanostructured thin film, a hybrid cell was designed and the total thickness was below 500 nm on a plastic substrate. Piezoelectric touch signals were demonstrated under independent and simultaneous operations with respect to photo-induced charges. Different levels of piezoelectric output signals from different magnitudes of touching pressures suggest new user-interface functions from our hybrid cell. From a signal controller, the decoupled performance of a hybrid cell as an energy harvester and a touch sensor was confirmed. Our hybrid approach does not require additional assembly processes for such multiplex systems of an energy harvester and a touch sensor since we utilize the coupled material properties of ZnO and output signal processing. Furthermore, the hybrid cell can provide a multi-type energy harvester by both solar and mechanical touching energies. PMID:20829570

Choi, Dukhyun; Lee, Keun Young; Lee, Kang Hyuck; Kim, Eok Su; Kim, Tae Sang; Lee, Sang Yoon; Kim, Sang-Woo; Choi, Jae-Young; Kim, Jong Min

2010-10-01

393

Electromagnetic Energy Harvester by Using NdFeB Sputtered on High Aspect Ratio Si Structure

NASA Astrophysics Data System (ADS)

This study addresses the design optimization of the electromagnetic energy harvester consisting of the sputtered NdFeB film on a high aspect ratio corrugated Si structure and Au electroplated serpentine coil. The high-aspect-ratio Si structure has advantages that the magnetic flux density change is caused by distance change between the coil and magnet film on the fine-patterned corrugated Si, and it is easier to fabricate with high yield than previous study. We also optimized design parameters such as width and depth of the trench, coil size by using FEM analysis and theoretical calculations. Assuming the mass size of 10×10 mm2, the trench depth of the 400 ?m, the vibration amplitude of 40 ?m p-p and the vibration frequency of 100 Hz, the maximum output power of 12 nW and the maximum electromotive force of 4 mV are obtained for 60 ?m and 80 ?m magnet widths, respectively.

Tanaka, Y.; Fujita, T.; Kotoge, T.; Yamaguchi, K.; Sonoda, K.; Kanda, K.; Maenaka, K.

2013-12-01

394

A 0.35?m CMOS energy processor with multiple inputs from solar, thermal and vibration energy sources is presented. Dual-path architecture for energy harvesting is proposed that has up to 13% higher conversion efficiency compared to the conventional two stage storage-regulation architecture. To minimize the cost and form factor, a single inductor has been time shared for all converters. A novel low

Saurav Bandyopadhyay; Anantha P. Chandrakasan

2011-01-01

395

NASA Astrophysics Data System (ADS)

A novel class of piezoelectric-based energy-harvesting power sources has been developed for gun-fired munitions and similar high-G applications. The power sources are designed to harvest energy primarily from the firing acceleration, but from in-flight vibratory motions as well. During the firing, a spring-mass element reacts to the axial acceleration, deforming and storing mechanical potential energy. After the projectile has exited the muzzle, the spring-mass element is free to vibrate, and the energy of the vibration is harvested using piezoelectric materials. These piezoelectric-based devices have been shown to produce enough electrical energy for many applications such as fuzing, and are able to eliminate the need for chemical batteries in many applications. When employed in fuzing applications, the developed power sources have the added advantage of providing augmented safety, since the fuzing electronics are powered only after the projectile has exited the muzzle and traveled a safe distance from the weapon platform. An overview of the development of these novel power sources is provided, especially designing and packaging for the high-G environment. Extensive laboratory and field testing has been performed on various prototypes; the methods and results of these experiments are presented. In addition to presenting the development and validation of this technology, methods for integrating the generators into different classes of projectiles are discussed along with strategies for manufacturing. This technology is currently validated to the extent that prototype devices have been successfully fired on-board actual gun-fired projectiles, demonstrating survivability and indicating performance. Strategies for designing the devices for a particular round and transitioning to commercialization are also discussed.

Rastegar, J.; Murray, R.

2010-03-01

396

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

397

Energy harvesting photodiodes with integrated 2D diffractive storage capacitance

Integrating photodiodes with logic and exploiting on-die interconnect capacitance for energy storage can enable new, low-cost energy harvesting wireless systems. To further explore the tradeoffs between optical efficiency and capacitive energy storage for integrated photodiodes, an array of photovoltaics with various diffractive storage capacitors was designed in TSMC's 90nm CMOS technology. Transient effects from interfacing the photodiodes with switching regulators

Nathaniel J. Guilar; Erin G. Fong; Travis Kleeburg; Diego R. Yankelevich; Rajeevan Amirtharajah

2008-01-01

398

Amplified energy harvester from footsteps: design, modeling, and experimental analysis

NASA Astrophysics Data System (ADS)

This paper presents the design, modeling and experimental analysis of an amplified footstep energy harvester. With the unique design of amplified piezoelectric stack harvester the kinetic energy generated by footsteps can be effectively captured and converted into usable DC power that could potentially be used to power many electric devices, such as smart phones, sensors, monitoring cameras, etc. This doormat-like energy harvester can be used in crowded places such as train stations, malls, concerts, airport escalator/elevator/stairs entrances, or anywhere large group of people walk. The harvested energy provides an alternative renewable green power to replace power requirement from grids, which run on highly polluting and global-warming-inducing fossil fuels. In this paper, two modeling approaches are compared to calculate power output. The first method is derived from the single degree of freedom (SDOF) constitutive equations, and then a correction factor is applied onto the resulting electromechanically coupled equations of motion. The second approach is to derive the coupled equations of motion with Hamilton's principle and the constitutive equations, and then formulate it with the finite element method (FEM). Experimental testing results are presented to validate modeling approaches. Simulation results from both approaches agree very well with experimental results where percentage errors are 2.09% for FEM and 4.31% for SDOF.

Wang, Ya; Chen, Wusi; Guzman, Plinio; Zuo, Lei

2014-04-01

399

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

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

400

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

401

Energy harvesting from the nonlinear oscillations of magnetic levitation

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

402

Piezoelectric Energy Harvesting with a Clamped Circular Plate: Experimental Study

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

403

Energy Harvesting and Storage Systems for Future AF Vehicles.

National Technical Information Service (NTIS)

This MURI project is aimed at designing a set of new energy- harvesting and storage materials (EHSM) and their integration of load-bearing airborne structures. The EHSM that were covered are, (i) organic solar cells based on two designs ,(a) dye-sensitize...

C. Xu G. Cao M. Taya S. Jenekhe Y. Kuga

2012-01-01

404

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