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1

Downhole vibration sensing by vibration energy harvesting  

E-print Network

This thesis outlines the design of a prototype electromagnetic induction vibration energy harvesting device for use in a downhole environment. First order models of the necessary components for a generic vibration energy ...

Trimble, A. Zachary

2007-01-01

2

MEMS for vibration energy harvesting  

NASA Astrophysics Data System (ADS)

In this paper, a capacitive vibration-to-electrical energy harvester was designed. An integrated process flow for fabricating the designed capacitive harvester is presented. For overcoming the disadvantage of depending on external power source in capacitive energy harvester, two parallel electrodes with different work functions are used as the two electrodes of the capacitor to generate a build-in voltage for initially charging the capacitor. The device is a sandwich structure of silicon layer in two glass layers with area of about 1 cm2. The silicon structure is fabricated by using silicon-on-insulator (SOI) wafer. The glass wafers are anodic bonded on to both sides of the SOI wafer to create a vacuum sealed package.

Li, Lin; Zhang, Yangjian; San, Haisheng; Guo, Yinbiao; Chen, Xuyuan

2008-03-01

3

Harvesting energy from non-ideal vibrations  

E-print Network

Energy harvesting has drawn significant interest for its potential to power autonomous low-power applications. Vibration energy harvesting is particularly well suited to industrial condition sensing, environmental monitoring ...

Chang, Samuel C

2013-01-01

4

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.

2011-06-01

5

On energy harvesting from ambient vibration  

Microsoft Academic Search

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

N. G. Stephen

2006-01-01

6

Harvesting Vibrational Energy Using Material Work Functions  

NASA Astrophysics Data System (ADS)

Vibration energy harvesters scavenge energy from mechanical vibrations to energise low power electronic devices. In this work, we report on vibration energy harvesting scheme based on the charging phenomenon occurring naturally between two bodies with different work functions. Such work function energy harvester (WFEH) is similar to electrostatic energy harvester with the fundamental distinction that neither external power supplies nor electrets are needed. A theoretical model and description of different operation modes of WFEHs are presented. The WFEH concept is tested with macroscopic experiments, which agree well with the model. The feasibility of miniaturizing WFEHs is shown by simulating a realistic MEMS device. The WFEH can be operated as a charge pump that pushes charge and energy into an energy storage element. We show that such an operation mode is highly desirable for applications and that it can be realised with either a charge shuttle or with switches. The WFEH is shown to give equal or better output power in comparison to traditional electrostatic harvesters. Our findings indicate that WFEH has great potential in energy harvesting applications.

Varpula, Aapo; Laakso, Sampo J.; Havia, Tahvo; Kyynäräinen, Jukka; Prunnila, Mika

2014-10-01

7

Harvesting vibrational energy using material work functions.  

PubMed

Vibration energy harvesters scavenge energy from mechanical vibrations to energise low power electronic devices. In this work, we report on vibration energy harvesting scheme based on the charging phenomenon occurring naturally between two bodies with different work functions. Such work function energy harvester (WFEH) is similar to electrostatic energy harvester with the fundamental distinction that neither external power supplies nor electrets are needed. A theoretical model and description of different operation modes of WFEHs are presented. The WFEH concept is tested with macroscopic experiments, which agree well with the model. The feasibility of miniaturizing WFEHs is shown by simulating a realistic MEMS device. The WFEH can be operated as a charge pump that pushes charge and energy into an energy storage element. We show that such an operation mode is highly desirable for applications and that it can be realised with either a charge shuttle or with switches. The WFEH is shown to give equal or better output power in comparison to traditional electrostatic harvesters. Our findings indicate that WFEH has great potential in energy harvesting applications. PMID:25348004

Varpula, Aapo; Laakso, Sampo J; Havia, Tahvo; Kyynäräinen, Jukka; Prunnila, Mika

2014-01-01

8

Harvesting Vibrational Energy Using Material Work Functions  

PubMed Central

Vibration energy harvesters scavenge energy from mechanical vibrations to energise low power electronic devices. In this work, we report on vibration energy harvesting scheme based on the charging phenomenon occurring naturally between two bodies with different work functions. Such work function energy harvester (WFEH) is similar to electrostatic energy harvester with the fundamental distinction that neither external power supplies nor electrets are needed. A theoretical model and description of different operation modes of WFEHs are presented. The WFEH concept is tested with macroscopic experiments, which agree well with the model. The feasibility of miniaturizing WFEHs is shown by simulating a realistic MEMS device. The WFEH can be operated as a charge pump that pushes charge and energy into an energy storage element. We show that such an operation mode is highly desirable for applications and that it can be realised with either a charge shuttle or with switches. The WFEH is shown to give equal or better output power in comparison to traditional electrostatic harvesters. Our findings indicate that WFEH has great potential in energy harvesting applications. PMID:25348004

Varpula, Aapo; Laakso, Sampo J.; Havia, Tahvo; Kyynäräinen, Jukka; Prunnila, Mika

2014-01-01

9

On energy harvesting from ambient vibration  

NASA Astrophysics Data System (ADS)

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 analysed in detail. The amplitude of the seismic mass is limited in any practical device and this, together with the magnitude and frequency of the excitation define the maximum power that can be extracted from the environment. The overall damping coefficient (part of which is mechanical) is associated with the harvesting and dissipation of energy and also the transfer of energy from the vibrating base into the system. It is shown that net energy flow from the base through the damper is positive (negative) for ?>?n (?harvesting energy over a wider band of excitation frequencies on either side of the natural frequency, is smaller, but will harvest marginally less power. One possible strategy for variable amplitude excitation is proposed.

Stephen, N. G.

2006-05-01

10

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.

2008-03-01

11

Potential system efficiencies for MEMS vibration energy harvesting  

Microsoft Academic Search

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

S. Behrens

2007-01-01

12

Piezoelectric energy harvesting from hybrid vibrations  

NASA Astrophysics Data System (ADS)

The concept of harvesting energy from ambient and galloping vibrations of a bluff body with a triangular cross-section geometry is investigated. A piezoelectric transducer is attached to the transverse degree of freedom of the body in order to convert these vibrations to electrical energy. A coupled nonlinear distributed-parameter model is developed that takes into consideration the galloping force and moment nonlinearities and the base excitation effects. The aerodynamic loads are modeled using the quasi-steady approximation. Linear analysis is performed to determine the effects of the electrical load resistance and wind speed on the global damping and frequency of the harvester as well as on the onset of instability. Then, nonlinear analysis is performed to investigate the impact of the base acceleration, wind speed, and electrical load resistance on the performance of the harvester and the associated nonlinear phenomena that take place. The results show that, depending on the interaction between the base and galloping excitations, and the considered values of the wind speed, base acceleration, and electrical load resistance, different nonlinear phenomena arise while others disappear. Short- and open-circuit configurations for different wind speeds and base accelerations are assessed. The results show that the maximum levels of harvested power are accompanied by a minimum transverse displacement when varying the electrical load resistance.

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

2014-02-01

13

Energy harvesting from wind-induced vibration of suspension bridges  

E-print Network

Recently, an extensive amount of research has been focused on energy harvesting from structural vibration sources for wireless self-powered microsystem applications. One method of energy harvesting is using electromagnetic ...

Shi, Miao, M. Eng. Massachusetts Institute of Technology

2013-01-01

14

Piezoelectric energy harvesting from traffic-induced bridge vibrations  

E-print Network

for self powered health monitoring sensor nodes. As traffic-induced bridge vibrations are low frequencyPiezoelectric energy harvesting from traffic-induced bridge vibrations Micha¨el Peigney1 harvesting of traffic-induced vibrations in bridges. Using a pre-stressed concrete highway bridge as a case

Paris-Sud XI, Université de

15

Multiple cell configuration electromagnetic vibration energy harvester  

NASA Astrophysics Data System (ADS)

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

Marin, Anthony; Bressers, Scott; Priya, Shashank

2011-07-01

16

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

17

Energy harvesting of random wide-band vibrations with applications to an electro-magnetic rotational energy harvester  

E-print Network

In general, vibration energy harvesting is the scavenging of ambient vibration by transduction of mechanical kinetic energy into electrical energy. Many mechanical or electro-mechanical systems produce mechanical vibrations. ...

Trimble, A. Zachary

2011-01-01

18

Magnetic induction systems to harvest energy from mechanical vibrations  

E-print Network

This thesis documents the design process for magnetic induction systems to harvest energy from mechanical vibrations. Two styles of magnetic induction systems - magnet-through-coil and magnet-across-coils - were analyzed. ...

Jonnalagadda, Aparna S

2007-01-01

19

Modeling and design of a MEMS piezoelectric vibration energy harvester  

E-print Network

The modeling and design of MEMS-scale piezoelectric-based vibration energy harvesters (MPVEH) are presented. The work is motivated by the need for pervasive and limitless power for wireless sensor nodes that have application ...

Du Toit, Noël Eduard

2005-01-01

20

Liquid-encapsulated energy harvester for low frequency vibrations  

Microsoft Academic Search

This paper presents the design, fabrication, and testing of prototype liquid-encapsulated energy harvester (LEEH) using PVDF electrets. Unlike harvesters reported in previous literature, this LEEH uses flowing liquid rather than resonating structures to induce variable capacitance, thus is more suitable for low frequency vibration energy harvesting. Manufactured prototypes with three different types of liquid (N-methyl-2pyrrolidone, N, N-Dimethylformamide, and glycerin) are

L. Bu; X. M. Wu; X. H. Wang; L. T. Liu

2011-01-01

21

Piezoelectric energy harvesting from traffic-induced bridge vibrations  

NASA Astrophysics Data System (ADS)

This paper focuses on energy harvesting from traffic-induced vibrations in bridges. Using a pre-stressed concrete highway bridge as a case study, in situ vibration measurements are presented and analysed. From these results, a prototype of a cantilever piezoelectric harvester is designed, tested and modelled. Even though the considered bridge vibrations are characterized by small amplitude and a low frequency (i.e. below 15 Hz), it is shown that mean power of the order of 0.03 mW can be produced, with a controlled voltage between 1.8 and 3.6 V. A simple model is proposed for theoretical prediction of the delivered power in terms of traffic intensity. This model shows good agreement with the experimental results and leads to a simple but effective design rule for piezoelectric harvesters to be used on bridges.

Peigney, Michaël; Siegert, Dominique

2013-09-01

22

A Branched Beam-Based Vibration Energy Harvester  

NASA Astrophysics Data System (ADS)

In this paper, a strategy to utilize a branched beam system to improve the frequency response characteristic of vibration energy harvesting is demonstrated. A basic unit of the device consists of several branch beams with proof mass at their ends and one main cantilever beam with a piezoelectric component at its root and proof mass at its end. The device can utilize the resonance of the branch beams and main beam to generate multiple output voltage peaks, providing a better frequency response characteristic than that of the conventional piezoelectric vibration energy harvester. Multiple branch structure and multiple basic units with similar structures can be connected to generate more output voltage peaks in the frequency response characteristic. Only one piezoelectric component is needed in the device, which makes it competitive in the management of harvested electric energy.

Zhang, Guangcheng; Hu, Junhui

2014-09-01

23

A Branched Beam-Based Vibration Energy Harvester  

NASA Astrophysics Data System (ADS)

In this paper, a strategy to utilize a branched beam system to improve the frequency response characteristic of vibration energy harvesting is demonstrated. A basic unit of the device consists of several branch beams with proof mass at their ends and one main cantilever beam with a piezoelectric component at its root and proof mass at its end. The device can utilize the resonance of the branch beams and main beam to generate multiple output voltage peaks, providing a better frequency response characteristic than that of the conventional piezoelectric vibration energy harvester. Multiple branch structure and multiple basic units with similar structures can be connected to generate more output voltage peaks in the frequency response characteristic. Only one piezoelectric component is needed in the device, which makes it competitive in the management of harvested electric energy.

Zhang, Guangcheng; Hu, Junhui

2014-11-01

24

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

25

Efficiency Enhancement of a Cantilever-Based Vibration Energy Harvester  

PubMed Central

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). PMID:24366177

Kubba, Ali E.; Jiang, Kyle

2014-01-01

26

Multi-link piezoelectric structure for vibration energy harvesting  

NASA Astrophysics Data System (ADS)

Work in piezoelectric vibration energy harvesting has typically focused on single member cantilevered structures with transverse tip displacement at a known frequency, taking advantage of the optimal coupling characteristics of piezoceramics in the 3-1 bending mode. Multi-member designs could be advantageous in delivering power to a load in environments with random or wide-band vibrations. The design presented in this work consists of two hinged piezoceramic (PZT-5A) beams x-poled for series operation. Each beam measures 31.8mm x 12.7mm x 0.38mm and consists of two layers of nickel-plated piezoceramic adhered to a brass center shim. The hinge device consists of two custom-machined aluminum attachments epoxied to the end of a beam and connected using a 1.59mm diameter alloy steel dowel. A stainless steel torsion spring is placed over the pin and attached to the aluminum body to provide a restoring torque when under rotation. The design is modeled using the piezoelectric constitutive equations to solve for voltage and power for a set of electromechanical boundary conditions. Experimental measurements on the design are achieved by bolting one end of the structure to a vibration shaker and fixing the other to a rigid framework of industrial aluminum framing material. For a given frequency of vibration, power output of the structure can be obtained by measuring voltage drop across a resistive load.

Aryanpur, Rameen M.; White, Robert D.

2012-04-01

27

A comparison of power output from linear and nonlinear kinetic energy harvesters using real vibration data  

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

28

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

Microsoft Academic Search

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

29

Abstract--This paper presents ambient mechanical vibrations as an alternative source for energy harvesting, especially  

E-print Network

Abstract--This paper presents ambient mechanical vibrations as an alternative source for energy harvesting, especially beneficial where alternatives such as light, wind, biomass and thermal energy are limited, e.g., powering underground sensors. Transduction of ambient kinetic energy, e.g., the vibrations

Kumar, Ratnesh

30

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

NASA Astrophysics Data System (ADS)

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

Miller, Lindsay Margaret

31

DESIGN CONSIDERATIONS FOR MEMS-SCALE PIEZOELECTRIC MECHANICAL VIBRATION ENERGY HARVESTERS  

Microsoft Academic Search

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

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

2005-01-01

32

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

33

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

PubMed

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

34

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

NASA Astrophysics Data System (ADS)

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

Karami, M. Amin; Inman, Daniel J.

2011-03-01

35

Design of energy harvesting systems for harnessing vibrational motion from human and vehicular motion  

NASA Astrophysics Data System (ADS)

In much of the vibration-based energy harvesting literature, devices are modeled, designed, and tested for dissipating energy across a resistive load at a single base excitation frequency. This paper presents several practical scenarios germane to tracking, sensing, and wireless communication on humans and land vehicles. Measured vibrational data from these platforms are used to provide a time-varying, broadband input to the energy harvesting system. Optimal power considerations are given for several circuit topologies, including a passive rectifier circuit and active, switching methods. Under various size and mass constraints, the optimal design is presented for two scenarios: walking and idling a car. The frequency response functions are given alongside time histories of the power harvested using the experimental base accelerations recorded. The issues involved in designing an energy harvester for practical (i.e. timevarying, non-sinusoidal) applications are discussed.

Wickenheiser, Adam; Garcia, Ephrahim

2010-04-01

36

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

Microsoft Academic Search

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

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

2009-01-01

37

The dynamic characteristics of harvesting energy from mechanical vibration via piezoelectric conversion  

NASA Astrophysics Data System (ADS)

As an alternative power solution for low-power devices, harvesting energy from the ambient mechanical vibration has received increasing research interest in recent years. In this paper we study the transient dynamic characteristics of a piezoelectric energy harvesting system including a piezoelectric energy harvester, a bridge rectifier, and a storage capacitor. To accomplish this, this energy harvesting system is modeled, and the charging process of the storage capacitor is investigated by employing the in-phase assumption. The results indicate that the charging voltage across the storage capacitor and the gathered power increase gradually as the charging process proceeds, whereas the charging rate slows down over time as the charging voltage approaches to the peak value of the piezoelectric voltage across the piezoelectric materials. In addition, due to the added electrical damping and the change of the system natural frequency when the charging process is initiated, a sudden drop in the vibration amplitude is observed, which in turn affects the charging rate. However, the vibration amplitude begins to increase as the charging process continues, which is caused by the decrease in the electrical damping (i.e., the decrease in the energy removed from the mechanical vibration). This electromechanical coupling characteristic is also revealed by the variation of the vibration amplitude with the charging voltage.

Fan, Kang-Qi; Ming, Zheng-Feng; Xu, Chun-Hui; Chao, Feng-Bo

2013-10-01

38

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

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

39

Theoretical investigations of energy harvesting efficiency from structural vibrations using piezoelectric and electromagnetic oscillators.  

PubMed

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

40

Nonlinear vibration control and energy harvesting of a beam using a nonlinear energy sink and a piezoelectric device  

NASA Astrophysics Data System (ADS)

This paper presents an optimal design for a system comprising a nonlinear energy sink (NES) and a piezoelectric-based vibration energy harvester attached to a free-free beam under shock excitation. The energy harvester is used for scavenging vibration energy dissipated by the NES. Grounded and ungrounded configurations are examined and the systems parameters are optimized globally to both maximize the dissipated energy by the NES and increase the harvested energy by piezoelectric element. A satisfactory amount of energy has been harvested as electric power in both configurations. The realization of nonlinear vibration control through one-way irreversible nonlinear energy pumping and optimizing the system parameters result in acquiring up to 78 percent dissipation of the grounded system energy.

Nili Ahmadabadi, Z.; Khadem, S. E.

2014-09-01

41

Self-Powered Kinetic Energy Harvesters for Seek-Induced Vibrations in Hard Disk Drives  

NASA Astrophysics Data System (ADS)

Energy harvesters with battery charging circuitry, which collect wasted kinetic energy from a magnetic disk drive's rotary actuator seek operations and flexible cable vibrations, are proposed, prototyped and presented in this paper. Depending on a disk drive's form factor and seek format, it is suggested by the present study that the harvested energy can be optimized by tuning the harvester's natural frequencies to major frequency content in the rotary actuator's excitation. It is demonstrated in this study that with prototype energy harvester systems, one can easily light up a regular LED. The work presented in this paper has implications in energy saving and recycling wasted mechanical energy for other low-power electronic applications in magnetic disk drive storage devices.

Chang, Jen-Yuan (James; Gutierrez, Mike

42

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

E-print Network

vibrations Soon-Duck Kwon1 , Jinkyoo Park2 and Kincho Law2 1 Department of Civil Engineering, ChonbukElectromagnetic energy harvester with repulsively stacked multilayer magnets for low frequency National University, Chonju, Chonbuk, Korea. Email: sdkwon@chonbuk.ac.kr 2 Department of Civil

Stanford University

43

Exploitation of a tristable nonlinear oscillator for improving broadband vibration energy harvesting  

NASA Astrophysics Data System (ADS)

Numerical and experimental investigations of a broadband vibration energy harvester with triple-well are presented. The nonlinear restoring force of the tristable oscillator is experimentally identified as a high order polynomial that depends on the relative spacing and locations of the magnets in the magnetically coupled piezoelectric cantilever. Simulations and experiments are performed at different harmonic excitation levels ranging from 10 to 35 Hz. The tristable energy harvester possesses the unique jump characteristics of oscillation center stemming from excitation level and initial displacements. Its broad frequency range of 15.1-32.5 Hz is obtained from the transition among three wells. It is also demonstrated that the tristable nonlinear oscillator will be more helpful to improve the broadband performance for harvesting vibration energy under low frequency excitations.

Zhou, Shengxi; Cao, Junyi; Lin, Jing; Wang, Zezhou

2014-09-01

44

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

45

Switched-mode impedance synthesis for electrical tuning of a vibration energy harvester  

NASA Astrophysics Data System (ADS)

Switched-mode power circuits are able to efficiently synthesise a variable complex load impedance that can tune a vibration energy harvester, whilst also providing rectification and feeding the harvested energy into a DC store. The electrical tuning system presented in this paper is based upon a boost rectifier configured as a variable power factor converter. Its performance is benchmarked against a more basic resistance emulator where it is demonstrated that electrical tuning provides an increase in power bandwidth of over three times. The paper describes the experimental results of electrical tuning in some detail and elucidates the design challenges for these systems.

Bowden, J. A.; Burrow, S. G.; Clare, L. R.

2013-12-01

46

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

NASA Astrophysics Data System (ADS)

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

Zhao, S.; Erturk, A.

2013-01-01

47

A two-dimensional broadband vibration energy harvester using magnetoelectric transducer  

SciTech Connect

In this study, a magnetoelectric vibration energy harvester was demonstrated, which aims at addressing the limitations of the existing approaches in single dimensional operation with narrow working bandwidth. A circular cross-section cantilever rod, not a conventional thin cantilever beam, was adopted to extract vibration energy in arbitrary in-plane motion directions. The magnetic interaction not only resulted in a nonlinear motion of the rod with increased frequency bandwidth, but also contributed to a multi-mode motion to exhibit double power peaks. In energy harvesting with in-plane directions, it showed a maximum bandwidth of 4.4?Hz and power of 0.59?mW, with acceleration of 0.6?g (with g?=?9.8?m?s{sup ?2})

Yang, Jin, E-mail: yangjin@cqu.edu.cn; Wen, Yumei; Li, Ping; Yue, Xihai; Yu, Qiangmo; Bai, Xiaoling [Department of Optoelectronic Engineering, Research Center of Sensors and Instruments, Chongqing University, Chongqing 400044 (China)] [Department of Optoelectronic Engineering, Research Center of Sensors and Instruments, Chongqing University, Chongqing 400044 (China)

2013-12-09

48

An auto-parametrically excited vibration energy harvester  

E-print Network

resonance. The authors however, have previously demonstrated an alter- native: parametric resonance at both macro-scale [16, 17] and MEMS scale [18, 19], outperforming the same device driven into direct resonance by over an order of magnitude in power output... compromises the absolute power output attainable, the piezoceramic still acts as a viable vibration sensor to achieve qualitative characterisation and a relative quantitative comparison when the prototype is driven into direct and parametric resonance. Results...

Jia, Yu; Seshia, Ashwin A.

2014-01-01

49

Harvesting microalgal biomass using a magnetically induced membrane vibration (MMV) system: filtration performance and energy consumption.  

PubMed

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

50

Repulsively driven frequency-increased-generators for durable energy harvesting from ultra-low frequency vibration.  

PubMed

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

51

Repulsively driven frequency-increased-generators for durable energy harvesting from ultra-low frequency vibration  

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

52

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

NASA Astrophysics Data System (ADS)

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

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

2011-04-01

53

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

54

Global Nonlinear Analysis of Piezoelectric Energy Harvesting from Ambient and Aeroelastic Vibrations  

NASA Astrophysics Data System (ADS)

Converting vibrations to a usable form of energy has been the topic of many recent investigations. The ultimate goal is to convert ambient or aeroelastic vibrations to operate low-power consumption devices, such as microelectromechanical systems, heath monitoring sensors, wireless sensors or replacing small batteries that have a finite life span or would require hard and expensive maintenance. The transduction mechanisms used for transforming vibrations to electric power include: electromagnetic, electrostatic, and piezoelectric mechanisms. Because it can be used to harvest energy over a wide range of frequencies and because of its ease of application, the piezoelectric option has attracted significant interest. In this work, we investigate the performance of different types of piezoelectric energy harvesters. The objective is to design and enhance the performance of these harvesters. To this end, distributed-parameter and phenomenological models of these harvesters are developed. Global analysis of these models is then performed using modern methods of nonlinear dynamics. In the first part of this Dissertation, global nonlinear distributed-parameter models for piezoelectric energy harvesters under direct and parametric excitations are developed. The method of multiple scales is then used to derive nonlinear forms of the governing equations and associated boundary conditions, which are used to evaluate their performance and determine the effects of the nonlinear piezoelectric coefficients on their behavior in terms of softening or hardening. In the second part, we assess the influence of the linear and nonlinear parameters on the dynamic behavior of a wing-based piezoaeroelastic energy harvester. The system is composed of a rigid airfoil that is constrained to pitch and plunge and supported by linear and nonlinear torsional and flexural springs with a piezoelectric coupling attached to the plunge degree of freedom. Linear analysis is performed to determine the effects of the linear spring coefficients and electrical load resistance on the flutter speed. Then, the normal form of the Hopf bifurcation ( utter) is derived to characterize the type of instability and determine the effects of the aerodynamic nonlinearities and the nonlinear coefficients of the springs on the system's stability near the bifurcation. This is useful to characterize the effects of different parameters on the system's output and ensure that subcritical or "catastrophic" bifurcation does not take place. Both linear and nonlinear analyses are then used to design and enhance the performance of these harvesters. In the last part, the concept of energy harvesting from vortex-induced vibrations of a circular cylinder is investigated. The power levels that can be generated from these vibrations and the variations of these levels with the freestream velocity are determined. A mathematical model that accounts for the coupled lift force, cylinder motion and generated voltage is presented. Linear analysis of the electromechanical model is performed to determine the effects of the electrical load resistance on the natural frequency of the rigid cylinder and the onset of the synchronization region. The impacts of the nonlinearities on the cylinder's response and energy harvesting are then investigated.

Abdelkefi, Abdessattar

55

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

56

A distributed parameter electromechanical and statistical model for energy harvesting from turbulence-induced vibration  

NASA Astrophysics Data System (ADS)

Extensive research has been done on the topics of both turbulence-induced vibration and vibration based energy harvesting; however, little effort has been put into bringing these two topics together. Preliminary experimental studies have shown that piezoelectric structures excited by turbulent flow can produce significant amounts of useful power. This research could serve to benefit applications such as powering remote, self-sustained sensors in small rivers or air ventilation systems where turbulent fluid flow is a primary source of ambient energy. A novel solution for harvesting energy in these unpredictable fluid flow environments was explored by the authors in previous work, and a harvester prototype was developed. This prototype, called piezoelectric grass, has been the focus of many experimental studies. In this paper the authors present a theoretical analysis of the piezoelectric grass harvester modeled as a single unimorph cantilever beam exposed to turbulent cross-flow. This distributed parameter model was developed using a combination of both analytical and statistical techniques. The analytical portion uses a Rayleigh–Ritz approximation method to describe the beam dynamics, and utilizes piezoelectric constitutive relationships to define the electromechanical coupling effects. The statistical portion of the model defines the turbulence-induced forcing function distributed across the beam surface. The model presented in this paper was validated using results from several experimental case studies. Preliminary results show that the model agrees quite well with experimental data. A parameter optimization study was performed with the proposed model. This study demonstrated how a new harvester could be designed to achieve maximum power output in a given turbulent fluid flow environment.

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

2014-11-01

57

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

PubMed

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

58

A general modal approach for the development of optimal multi-layer stacked vibration energy harvesters  

NASA Astrophysics Data System (ADS)

Piezoelectric vibration energy harvesters with multi-layer stacked structures have been developed. They consist of multi-layer beams, of zigzag configurations, with rigid masses attached between the beams. The rigid masses, which also serve as spacers, are attached to each layer to tune the frequencies of the harvester. Close resonance frequencies and considerable power output can be achieved in multiple modes by varying the positions of the masses. A modal approach is introduced to determine the modal performance conveniently using the mass ratio and the modal electromechanical coupling coefficient, and the required modal parameters are derived using the finite element method. Mass ratio represents the influence of modal mechanical behaviour on the power density. Since the modes with larger mass ratios cause the remaining modes to have smaller mass ratios and lower power densities, a screening process using the modal approach is developed to determine the optimal or near-optimal performance of the harvesters when altering mass positions. This procedure obviates the need for full analysis by pre-selecting the harvester configurations with close resonances and favourable values of mass ratio initially. Furthermore, the multi-layer stacked designs using the modal approach can be used to develop harvesters with different sizes with the power ranging from microwatts to milliwatts.

Xiong, Xingyu; Oyadiji, S. Olutunde

2014-10-01

59

The fabrication of vibration energy harvester arrays based on AlN piezoelectric film  

NASA Astrophysics Data System (ADS)

The fabrication and measurement results of the vibration energy harvester arrays based on the piezoelectric aluminum nitride (AlN) film are presented. The structure design and fabrication process of the device are introduced. The key material, the AlN film with crystal orientation (002), was deposited by pulsed-DC magnetron sputtering and characterized by X-ray diffraction (XRD). The resonant frequency, power out, and the open circuit voltage of the device are detected. The optimized load of 80 k? and a remarkable maximum power out of 30.4 ?W are obtained when the acceleration of 0.9g (g is standard gravity acceleration) is applied.

Zhengguo, Shang; Dongling, Li; Zhiyu, Wen; Xingqiang, Zhao

2013-11-01

60

Electrostatic vibration energy harvester with combined effect of electrical nonlinearities and mechanical impact  

NASA Astrophysics Data System (ADS)

This paper presents an advanced study including the design, characterization and theoretical analysis of a capacitive vibration energy harvester. Although based on a resonant electromechanical device, it is intended for operation in a wide frequency band due to the combination of stop-end effects and a strong biasing electrical field. The electrostatic transducer has an interdigited comb geometry with in-plane motion, and is obtained through a simple batch process using two masks. A continuous conditioning circuit is used for the characterization of the transducer. A nonlinear model of the coupled system ‘transduce-conditioning circuit’ is presented and analyzed employing two different semi-analytical techniques together with precise numerical modelling. Experimental results are in good agreement with results obtained from numerical modelling. With the 1 g amplitude of harmonic external acceleration at atmospheric pressure, the system transducer-conditioning circuit has a half-power bandwidth of more than 30% and converts more than 2 µW of the power of input mechanical vibrations over the range of 140 and 160 Hz. The harvester has also been characterized under stochastic noise-like input vibrations.

Basset, P.; Galayko, D.; Cottone, F.; Guillemet, R.; Blokhina, E.; Marty, F.; Bourouina, T.

2014-03-01

61

Modeling and Simulation of Linear and Nonlinear MEMS Scale Electromagnetic Energy Harvesters for Random Vibration Environments  

PubMed Central

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

Sassani, Farrokh

2014-01-01

62

Modeling and Tuning for Vibration Energy Harvesting using a Piezoelectric Bimorph  

NASA Astrophysics Data System (ADS)

With the development of wireless sensors and other devices, the need for continuous power supply with high reliability is growing ever more. The traditional battery power supply has the disadvantage of limited duration of continuous power supply capability so that replacement for new batteries has to be done regularly. This can be quite inconvenient and sometimes quite difficult especially when the sensors are located in places not easily accessible such as the inside of a machine or wild field. This situation stimulates the development of renewable power supply which can harvest energy from the environment. The use of piezoelectric materials to converting environment vibration to electrical energy is one of the alternatives of which a broad range of research has been done by many researchers, focusing on different issues. The improvement of efficiency is one of the most important issues in vibration based energy harvesting. For this purpose different methods are devised and more accurate modeling of coupled piezoelectric mechanical systems is investigated. In the current paper, the research is focused on improving voltage generation of a piezoelectric bimorph on a vibration beam, as well as the analytical modeling of the same system. Also an initial study is conducted on the characteristics of the vibration of Zinc oxide (ZnO) nanowire, which is a promising material for its coupled semiconducting and piezoelectric properties. The effect on the voltage generation by different placement of the piezoelectric bimorph on the vibrating beam is investigated. The relation between the voltage output and the curvature is derived which is used to explain the effect of placement on voltage generation. The effect of adding a lumped mass on the modal frequencies of the beam and on the curvature distribution is investigated. The increased voltage output from the piezoelectric bimorph by using appropriately selected mass is proved analytically and also verified by experiment. For the modeling of piezoelectric generator, different methods are employed to modeling the coupled dynamics of a piezoelectric bimorph on a vibrating beam as well as a simple piezoelectric bimorph cantilever. The modeling of piezoelectric bimorph as an alternative current (AC) source with internal capacitance and resistance is used to analyze a piezoelectric bimorph cantilever and to calculate the optimal external load resistance for maximal power output. The couple dynamics method based on Hamilton's Principle is applied in the modeling of the piezoelectric bimorph on a vibrating beam. Impulse response experiment shows this method has a better estimation of the experimental results than the curvature model. The coupled dynamics model is also applied to piezoelectric bimorph cantilever and the external load resistance is also determined by this to maximize the power output. The finite element equations for the piezoelectric materials in the element domain are theoretically derived. The procedure of modeling a piezoelectric on a vibrating beam is demonstrated base on the package of ANSYS. The frequency response of ZnO nanowires with different dimensions is derived analytically for ambient mediums with different damping ratios. With help from nano research lab of Dr. Yong Zhu and the student Feng Xu, an experiment is conducted which indentifies the first modal frequency of ZnO nanowires with different dimensions. The experimental modal frequencies are compared with the numerical results. The influence of the thickness of deposit on the modal frequency is also investigated by finite element modeling.

Cao, Yongqing

63

Note: A cubic electromagnetic harvester that convert vibration energy from all directions.  

PubMed

We investigate the output performance of a cubic harvester which can scavenge low-frequency vibration energy from all directions. By adjusting the size and shape of the inside magnets, higher induced voltages and output power can be achieved. The optimal magnet is found to be cubic shape with the length of 6.35 mm (25.6% volume ratio), which can generate 4.27 mV root mean square voltage and 2.45 ?W average power at the frequency of 28.86 Hz and acceleration of 1.17 g. The device is also demonstrated as a self-powered tilt sensor by measuring induced voltages at different tilt angles. PMID:25085194

Han, Mengdi; Qiu, Guolin; Liu, Wen; Meng, Bo; Zhang, Xiao-Sheng; Zhang, Haixia

2014-07-01

64

Note: A cubic electromagnetic harvester that convert vibration energy from all directions  

NASA Astrophysics Data System (ADS)

We investigate the output performance of a cubic harvester which can scavenge low-frequency vibration energy from all directions. By adjusting the size and shape of the inside magnets, higher induced voltages and output power can be achieved. The optimal magnet is found to be cubic shape with the length of 6.35 mm (25.6% volume ratio), which can generate 4.27 mV root mean square voltage and 2.45 ?W average power at the frequency of 28.86 Hz and acceleration of 1.17 g. The device is also demonstrated as a self-powered tilt sensor by measuring induced voltages at different tilt angles.

Han, Mengdi; Qiu, Guolin; Liu, Wen; Meng, Bo; Zhang, Xiao-Sheng; Zhang, Haixia

2014-07-01

65

Triboelectric nanogenerator built on suspended 3D spiral structure as vibration and positioning sensor and wave energy harvester.  

PubMed

An unstable mechanical structure that can self-balance when perturbed is a superior choice for vibration energy harvesting and vibration detection. In this work, a suspended 3D spiral structure is integrated with a triboelectric nanogenerator (TENG) for energy harvesting and sensor applications. The newly designed vertical contact-separation mode TENG has a wide working bandwidth of 30 Hz in low-frequency range with a maximum output power density of 2.76 W/m(2) on a load of 6 M?. The position of an in-plane vibration source was identified by placing TENGs at multiple positions as multichannel, self-powered active sensors, and the location of the vibration source was determined with an error less than 6%. The magnitude of the vibration is also measured by the output voltage and current signal of the TENG. By integrating the TENG inside a buoy ball, wave energy harvesting at water surface has been demonstrated and used for lighting illumination light, which shows great potential applications in marine science and environmental/infrastructure monitoring. PMID:24168315

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

2013-11-26

66

A Study on Design and Analysis of Hybrid Vibration Damper with Energy Harvesting and Optimal Damping Effect  

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

67

Vibration-Based MEMS Piezoelectric Energy Harvester (VMPEH) Modeling and Analysis for Green Energy Source  

Microsoft Academic Search

The wireless sensor network market is growing quickly yet is limited by existing short lifetime batteries. Providing a green, virtually infinite alternative power source to traditional energy sources will significantly expand applications for WSNs and other technologies, the use of piezoelectric materials to capitalize on the ambient vibrations surrounding a system is one method that has seen a dramatic rise

Salem Saadon; Othman Sidek

2011-01-01

68

Ambient vibration-based MEMS piezoelectric energy harvester for green energy source  

Microsoft Academic Search

The wireless sensor network (WSN) market is growing quickly yet is limited by existing short lifetime batteries. Providing a green, virtually infinite alternative power source to traditional energy sources will significantly expand applications for WSNs and other technologies, the use of piezoelectric materials to capitalize on the ambient vibrations surrounding a system is one method that has seen a dramatic

Salem Saadon; Othman Sidek

2011-01-01

69

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

70

A 1-mW vibration energy harvesting system for moth flight-control applications  

E-print Network

This thesis focuses on the approach and methodologies required to build a 1-mW energy-harvesting system for moth flight control applications. The crepuscular hawk moth Manduca sexta is the chosen test subject. This project ...

Chang, Samuel C

2010-01-01

71

Analysis of Energy Harvesting for Vibration-Motivated Wireless Sensor Networks  

E-print Network

techno- logical advances have fueled the development of a tiny, low- cost, and low-power node which in such as bridges, buildings, dams, ships, aircrafts, etc. Each node equipped with a vibration detecting card can inherent pros and cons. When vibrations are a dominant source of energy and solar light is not always

Lim, Sunho

72

Vibration analysis during grass harvesting according to ISO vibration standards  

Microsoft Academic Search

This research evaluated the working efficiency and comfort of operation by measuring vibration acceleration of tractors during grass harvesting. A real-time kinematic global positioning system and an inertial measurement unit installed in a tractor normally used by farmers during grass harvesting were used to acquire tractor vibration acceleration data. Analysis of the position and vibration acceleration data of tractors by

Tae-Hwan Kang; Yutaka Kaizu

2011-01-01

73

Design of high-efficiency vibration energy harvesters and experimental functional tests for improving bandwidth and tunability  

NASA Astrophysics Data System (ADS)

The reduction of power consumption of sensors allows the local power supply or wireless sensor networks. This paper introduces the results of design and experiments on devices for harvesting energy from vibrations of machines. The main contribution of this research is the empirical evaluation of different technical solutions able to improve harvester performances and sensing system duty cycle. Satisfactory results have been achieved in lowering of resonance by levitating suspensions and in increasing of Q-factor by studying the air flows. Output power values of 10mW (5.7Hz, 1.4g) and 115mW (3.2Hz, 0.2g) were obtained for piezoelectric and inductive harvesters respectively.

Somà, A.; De Pasquale, G.

2013-05-01

74

Demonstration of the effect of piezoelectric polarization vector on the performance of a vibration energy harvester  

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

75

Extremely low-loss rectification methodology for low-power vibration energy harvesters  

NASA Astrophysics Data System (ADS)

Because of its promise for the generation of wireless systems, energy harvesting technology using smart materials is the focus of significant reported effort. Various techniques and methodologies for increasing power extraction have been tested. One of the key issues with the existing techniques is the use of diodes in the harvesting circuits with a typical voltage drop of 0.7 V. Since most of the smart materials, and other transducers, do not produce large voltage outputs, this voltage drop becomes significant in most applications. Hence, there is a need for designing a rectification method that can convert AC to DC with minimal losses. This paper describes a new mechanical rectification scheme, designed using reed switches, in a full-bridge configuration that shows the capability of working with signals from millivolts to a few hundred volts with extremely low losses. The methodology has been tested for piezoelectric energy harvesters undergoing mechanical excitation.

Tiwari, R.; Ryoo, K.; Schlichting, A.; Garcia, E.

2013-06-01

76

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

Microsoft Academic Search

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

Rohan Dayal; Suman Dwari; Leila Parsa

2011-01-01

77

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

NASA Astrophysics Data System (ADS)

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

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

2011-07-01

78

Design and fabrication of a new system for vibration energy harvesting  

Microsoft Academic Search

Global simulations, designs and characterisations of a broadband vibration energy scavenging system are here reported. High damping electrostatic conversion structures have been investigated. Mathematical analytical models have been performed and confronted with ANSYS simulations. A scavenging electronics has also been developed: taking in account ohmic, capacitive and inductive losses, the global conversion efficiency has been calculated. Finally, a macro and

Ghislain Despesse; Thomas Jager; Jean-Jacques Chaillout; Jean-Michel Léger; Skandar Basrour

2005-01-01

79

Parametrically excited MEMS vibration energy harvesters with design approaches to overcome the initiation threshold amplitude  

NASA Astrophysics Data System (ADS)

Resonant-based vibration harvesters have conventionally relied upon accessing the fundamental mode of directly excited resonance to maximize the conversion efficiency of mechanical-to-electrical power transduction. This paper explores the use of parametric resonance, which unlike the former, the resonant-induced amplitude growth, is not limited by linear damping and wherein can potentially offer higher and broader nonlinear peaks. A numerical model has been constructed to demonstrate the potential improvements over the convention. Despite the promising potential, a damping-dependent initiation threshold amplitude has to be attained prior to accessing this alternative resonant phenomenon. Design approaches have been explored to passively reduce this initiation threshold. Furthermore, three representative MEMS designs were fabricated with both 25 and 10 ?m thick device silicon. The devices include electrostatic cantilever-based harvesters, with and without the additional design modification to overcome initiation threshold amplitude. The optimum performance was recorded for the 25 ?m thick threshold-aided MEMS prototype with device volume ˜0.147 mm3. When driven at 4.2 ms-2, this prototype demonstrated a peak power output of 10.7 nW at the fundamental mode of resonance and 156 nW at the principal parametric resonance, as well as a 23-fold decrease in initiation threshold over the purely parametric prototype. An approximate doubling of the half-power bandwidth was also observed for the parametrically excited scenario.

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

2013-11-01

80

The realization and performance of vibration energy harvesting MEMS devices based on an epitaxial piezoelectric thin film  

NASA Astrophysics Data System (ADS)

This paper focuses on the fabrication and evaluation of vibration energy harvesting devices by utilizing an epitaxial Pb(Zr0.2Ti0.8)O3 (PZT) thin film. The high quality of the c-axis oriented PZT layer results in a high piezoelectric coefficient and a low dielectric constant, which are key parameters for realizing high performance piezoelectric energy harvesters. Different cantilever structures, with and without a Si proof mass, are realized using micro-patterning techniques optimized for the epitaxial oxide layers, to maintain the piezoelectric properties throughout the process. The characteristics and the energy harvesting performances of the fabricated devices are experimentally investigated and compared against analytical calculations. The optimized device based on a 0.5 µm thick epitaxial PZT film, a cantilever beam of 1 mm × 2.5 mm × 0.015 mm, with a Si proof mass of 1 mm × 0.5 mm × 0.23 mm, generates an output power, current and voltage of, respectively, 13 µW g - 2, 48 µA g - 1 and 0.27 V g - 1 (g = 9.81 m s - 2) at the resonant frequency of 2.3 kHz for an optimal resistive load of 5.6 k?. The epitaxial PZT harvester exhibits higher power and current with usable voltage, while maintaining lower optimal resistive load as compared with other examples present in the literature. These results indicate the potential of epitaxial PZT thin films for the improvement of the performances of energy harvesting devices.

Isarakorn, D.; Briand, D.; Janphuang, P.; Sambri, A.; Gariglio, S.; Triscone, J.-M.; Guy, F.; Reiner, J. W.; Ahn, C. H.; de Rooij, N. F.

2011-02-01

81

Piezoelectric MEMS for energy harvesting  

E-print Network

Piezoelectric microelectromechanical systems (MEMS) have been proven to be an attractive technology for harvesting small magnitudes of energy from ambient vibrations. This technology promises to eliminate the need for ...

Kim, Sang-Gook

82

Stochastic quantification of the electric power generated by a piezoelectric energy harvester using a time-frequency analysis under non-stationary random vibrations  

NASA Astrophysics Data System (ADS)

Vibration energy, which is widely available, can be converted into electric energy using a piezoelectric energy harvester that generates alternating current in response to applied mechanical strain. For the last decade, there has been a strong surge of interest in developing an electromechanically-coupled analytical model of a piezoelectric energy harvester. Such a model is of great importance to enable understanding of the first principle of the piezoelectric transduction and to quantify harvestable electric power under a given vibration condition. However, existing analytical models that operate under an assumption of deterministic excitations cannot deal with the random nature present in realistic vibrations, even though this randomness considerably affects the variation in harvestable electric power. Furthermore, even when random vibrations are taken into account, existing stochastic analytical models can only be applied to stationary excitations, such as in the case of white Gaussian noise. This paper thus proposes a three-step framework for stochastic quantification of the electric power generated by a piezoelectric energy harvester under non-stationary random vibrations. First, we propose estimation of the time-varying power spectral density (PSD) of the input non-stationary random vibration using a statistical time-frequency analysis. The second step is to employ an existing electromechanical model as the linear operator for calculating the output voltage response. The final step is to estimate the time-varying PSD of the output voltage response. Following this three-step process, the expected electric power can be estimated from the autocorrelation function which is the inverse Fourier transform of the time-varying PSD of the output voltage response. The merits of the proposed framework are two-fold in that it enables: (i) quantification of the time-varying electric power generated under non-stationary random vibrations and (ii) consideration of the randomness in the design process of the energy harvester. Four case studies are used to demonstrate the effectiveness of the proposed framework.

Yoon, Heonjun; Youn, Byeng D.

2014-04-01

83

Ultra wide-bandwidth micro energy harvester  

E-print Network

An ultra wide-bandwidth resonating thin film PZT MEMS energy harvester has been designed, modeled, fabricated and tested. It harvests energy from parasitic ambient vibration at a wide range of amplitude and frequency via ...

Hajati, Arman

2011-01-01

84

A non-resonant, frequency up-converted electromagnetic energy harvester from human-body-induced vibration for hand-held smart system applications  

NASA Astrophysics Data System (ADS)

We present a non-resonant, frequency up-converted electromagnetic energy harvester that generates significant power from human-body-induced vibration, e.g., hand-shaking. Upon excitation, a freely movable non-magnetic ball within a cylinder periodically hits two magnets suspended on two helical compression springs located at either ends of the cylinder, allowing those to vibrate with higher frequencies. The device parameters have been designed based on the characteristics of human hand-shaking vibration. A prototype has been developed and tested both by vibration exciter (for non-resonance test) and by manual hand-shaking. The fabricated device generated 110 ?W average power with 15.4 ?W cm-3 average power density, while the energy harvester was mounted on a smart phone and was hand-shaken, indicating its ability in powering portable hand-held smart devices from low frequency (<5 Hz) vibrations.

Halim, Miah A.; Park, Jae Y.

2014-03-01

85

Design and fabrication of vibration based energy harvester using microelectromechanical system piezoelectric cantilever for low power applications.  

PubMed

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

86

Piezoelectric Energy Harvesting From Flutter  

NASA Astrophysics Data System (ADS)

With the increasing need for alternative sources of energy, a great deal of attention is drawn to harvesting energy from ambient vibration. These vibrations may be caused by fluid forces acting upon a structure. When a flexible structure is subject to a fluid flow, it loses stability at a certain flow velocity and starts to vibrate. This self-induced motion is called flutter where energy is continuously transferred from the fluid to the structure. In this study a piezoelectric film sensor is used as a fluttering object, to convert the motion to electrical energy, and the energy harvesting capacity of the proposed concept is investigated. An experimental setup, composed of data acquisition methods, is designed and the findings are validated by original test data. The results are also compared to similar literature and it is concluded that the proposed energy harvesting technique meets the requirements of the intended application.

Norouzi, Soroush

87

Dynamic analysis of an electrostatic energy harvesting system  

E-print Network

Traditional small-scale vibration energy harvesters have typically low efficiency of energy harvesting from low frequency vibrations. Several recent studies have indicated that introduction of nonlinearity can significantly ...

Niu, Feifei

2013-01-01

88

A MEMS electret generator with electrostatic levitation for vibration-driven energy-harvesting applications  

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

89

Simultaneous Energy Harvesting and Vibration Control of Structures with Tuned Mass Dampers  

E-print Network

Xiudong Tang and Lei Zuo* Department of Mechanical Engineering State University of New York at Stony Brook, such as Taipei 101 in Taipei, Citi Group in New York, and many others. The original TMD, which was invented loadings from the winds, earthquakes, water waves, traffics and human motions. The large vibration

Zuo, Lei

90

Piezoelectric Water Drop Energy Harvesting  

NASA Astrophysics Data System (ADS)

Piezoelectric materials convert mechanical deformation directly into electrical charges, which can be harvested and used to drive micropower electronic devices. The low power consumption of such systems on the scale of microwatts leads to the possibility of using harvested vibrational energy due to its almost universal nature. Vibrational energy harvested using piezoelectric cantilevers provides sufficient output for small-scale power applications. This work reports on vibrational energy harvesting from free-falling droplets at the tip of lead zirconate titanate piezoelectric-based cantilevers. The harvester incorporates a multimorph clamped-free cantilever made of lead zirconate titanate piezoelectric thick films. During the impact, the droplet's kinetic energy is transferred to the form of mechanical stress, forcing the piezoelectric structure to vibrate and thereby producing charges. Experimental results show an instantaneous drop-power of 2.15 mW cm-3 g-1. The scenario of a medium intensity of falling water drops, i.e., 200 drops per second, yielded a power of 0.48 W cm-3 g-1 per second.

Al Ahmad, Mahmoud

2014-02-01

91

An efficient piezoelectric energy-harvesting interface circuit using a Bias-Flip rectifier and shared inductor  

E-print Network

Energy harvesting is an emerging technology with applications to handheld, portable and implantable electronics. Harvesting ambient vibration energy through piezoelectric (PE) means is a popular energy harvesting technique ...

Ramadass, Yogesh Kumar

92

Motorcycle waste heat energy harvesting  

Microsoft Academic Search

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

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

2008-01-01

93

A Study on Energy Harvesting Aware Routing for Vibration-Motivated Wireless Sensor Networks  

E-print Network

-cost, and low-power node feasible and applicable to a wide range of applications built for WSNs. For example and locate the structural damages in such as bridges, buildings, dams, ships, aircrafts, etc. Each node of energy and solar light is not alway

Lim, Sunho

94

A three-dimensional electret-based micro power generator for low-level ambient vibrational energy harvesting  

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

95

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

96

Bias-Flip Technique for Frequency Tuning of Piezo-Electric Energy Harvesting Devices  

E-print Network

Devices that harvest electrical energy from mechanical vibrations have the problem that the frequency of the source vibration is often not matched to the resonant frequency of the energy harvesting device. Manufacturing ...

Zhao, Jianying

97

Energy harvesting from acoustic fields.  

PubMed

While energy harvesting from a variety of ambient sources (vibration, light, and wind) has been demonstrated and sensing and communication applications to exploit those sources have been developed, acoustic energy as an ambient energy source has not received similar attention, except for a few very specialized special cases; this "hot topic" will focus on the special cases. The reason for otherwise limited development comes down to the basic physics of how much energy is available within a "typical" acoustic field. For airborne sounds, the energy density in sound fields that are perceived by humans to be loud to painfully loud (e.g., 80 to 140 dB, or ?0.2 Pa to ?200 Pa) actually represent an extremely low available energy source. In consequence, means must be taken to intensify an acoustic response, for example through resonance, but even so, the available energy remains limited. But, what if the sound field is not "typical"? One of the exceptions which enables viable acoustic energy harvesting is the sound field that exists inside of an operating jet aircraft engine. Another exception is within pumped and pressurized fluid systems, where acoustic pressure variations may reach into the mega-Pascal (MPa) range. Energy harvesting from such a fluid-borne acoustic source is feasible for powering sensors and wireless communication systems, has been successfully demonstrated, and may yield commercialized technology within only a few years. PMID:25235677

Cunefare, Kenneth

2014-04-01

98

M-shaped asymmetric nonlinear oscillator for broadband vibration energy harvesting: Harmonic balance analysis and experimental validation  

NASA Astrophysics Data System (ADS)

Over the past few years, nonlinear oscillators have been given growing attention due to their ability to enhance the performance of energy harvesting devices by increasing the frequency bandwidth. Duffing oscillators are a type of nonlinear oscillator characterized by a symmetric hardening or softening cubic restoring force. In order to realize the cubic nonlinearity in a cantilever at reasonable excitation levels, often an external magnetic field or mechanical load is imposed, since the inherent geometric nonlinearity would otherwise require impractically high excitation levels to be pronounced. As an alternative to magnetoelastic structures and other complex forms of symmetric Duffing oscillators, an M-shaped nonlinear bent beam with clamped end conditions is presented and investigated for bandwidth enhancement under base excitation. The proposed M-shaped oscillator made of spring steel is very easy to fabricate as it does not require extra discrete components to assemble, and furthermore, its asymmetric nonlinear behavior can be pronounced yielding broadband behavior under low excitation levels. For a prototype configuration, linear and nonlinear system parameters extracted from experiments are used to develop a lumped-parameter mathematical model. Quadratic damping is included in the model to account for nonlinear dissipative effects. A multi-term harmonic balance solution is obtained to study the effects of higher harmonics and a constant term. A single-term closed-form frequency response equation is also extracted and compared with the multi-term harmonic balance solution. It is observed that the single-term solution overestimates the frequency of upper saddle-node bifurcation point and underestimates the response magnitude in the large response branch. Multi-term solutions can be as accurate as time-domain solutions, with the advantage of significantly reduced computation time. Overall, substantial bandwidth enhancement with increasing base excitation is validated experimentally, analytically, and numerically. As compared to the 3 dB bandwidth of the corresponding linear system with the same linear damping ratio, the M-shaped oscillator offers 3200, 5600, and 8900 percent bandwidth enhancement at the root-mean-square base excitation levels of 0.03g, 0.05g, and 0.07g, respectively. The M-shaped configuration can easily be exploited in piezoelectric and electromagnetic energy harvesting as well as their hybrid combinations due to the existence of both large strain and kinetic energy regions. A demonstrative case study is given for electromagnetic energy harvesting, revealing the importance of higher harmonics and the need for multi-term harmonic balance analysis for predicting the electrical power output accurately.

Leadenham, S.; Erturk, A.

2014-11-01

99

Ambient energy harvesting using ferroelectric materials  

NASA Astrophysics Data System (ADS)

Recent progresses in electronics allow powering complex systems using either batteries or environmental energy harvesting. However using batteries raises the problems of limited lifespan and recycling process, leading to the research of other energy sources for mobile electronics. Recent work on Synchronized Switch Harvesting (SSH) shows a significant improvement of energy harvesting from vibrations compared to standard techniques. Nevertheless, harvesting energy from vibrations necessitates that the electromechanical structure has to be driven by mechanical solicitations, which generally have a limited amount of energy. Therefore, for the design of efficient and truly applicable self-powered devices, combining several sources for energy harvesting would be greatly beneficial. Thermal energy is rarely considered due to the difficulty of getting efficient devices. However, the potential of such a source is one of the most important. This paper deals with energy harvesting using either piezoelectric or pyroelectric effect. Theoretical and experimental validations of thermal energy harvesting are presented and discussed. Standard thermodynamic cycles may be adapted in order to improve conversion effectiveness. Experimental converted energy as high as 160 mJ.cm -3.cycle -1 has been measured with a 35°C temperature variation, corresponding to 2.15% of Carnot efficiency.

Guyomar, Daniel; Sebald, Gaël; Pruvost, Sébastien; Lallart, Mickaël

2008-03-01

100

The physical acoustics of energy harvesting  

Microsoft Academic Search

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

Stewart Sherrit

2008-01-01

101

Harvesting traffic-induced vibrations for structural health monitoring of bridges  

Microsoft Academic Search

This paper discusses the development and testing of a renewable energy source for powering wireless sensors used to monitor the structural health of bridges. Traditional power cables or battery replacement are excessively expensive or infeasible in this type of application. An inertial power generator has been developed that can harvest traffic-induced bridge vibrations. Vibrations on bridges have very low acceleration

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

2011-01-01

102

Piezoelectric monolayers as nonlinear energy harvesters.  

PubMed

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 nm2 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

103

Development of MEMS piezoelectric energy harvesters  

Microsoft Academic Search

The research of powering devices in a microwatt range has been activated and developed by the emergence of low-power Very Large Scale Integration (VLSI) technology in the past few years. The powering devices require a size that is compatible with the application, sufficient power, and extended lifetime using permanent and ubiquitous energy sources. The piezoelectric energy harvester using vibration sources

Jung-Hyun Park

2010-01-01

104

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.

2008-03-01

105

Algae Harvest Energy Conversion  

Microsoft Academic Search

\\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

106

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

107

Piezoelectric Energy Harvesting Solutions  

PubMed Central

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. PMID:24618725

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

2014-01-01

108

A nonlinear energy sink with an energy harvester: Transient responses  

NASA Astrophysics Data System (ADS)

This paper investigates energy harvesting using nonlinear energy sink. First a novel apparatus is described in detail outlining how the essential nonlinearity and energy harvesting are achieved. Then the system modeling is addressed, including the equations of motion for the mechanical system and the electromechanical system, and a formula for the transduction factor. The experimental identification is conducted to determine several key parameters and relationships. Using the established models, a computer simulation is carried out to investigate the apparatuss performance under transient responses in terms of vibration absorption and energy harvesting. Finally experiments are conducted to validate the simulation results. It is shown that the system performs well, being capable of energy localization as well as broad band vibration absorption. The system is also shown to be capable of harvesting energy.

Kremer, Daniel; Liu, Kefu

2014-09-01

109

Energy Harvesting By Optimized Piezo Transduction Mechanism  

E-print Network

We report generation of electrical energy from nonlinear mechanical noises available in the ambient environment using optimized piezo transduction mechanisms. Obtaining energy from an ambient vibration has been attractive for remotely installed standalone microsystems and devices. The mechanical noises in the ambient environment can be converted to electrical energy by a piezo strip based on the principle of piezoelectric effect. In this work, we have designed and developed a standalone energy harvesting module based on piezo transduction mechanisms. Using this designed module we harvested noise energy and stored electrical energy in a capacitor. Using NI-PXI workstation with a LabVIEW programming, the output voltage of the piezo strip and voltage of the capacitor were measured and monitored. In this paper we discuss about the design, development, implementation, performance and characteristics of the energy harvesting module.

Boban, Bijo; Satheesh, U; Devaprakasam, D

2014-01-01

110

Development of energy harvesting device using piezoelectric material  

Microsoft Academic Search

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

111

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

E-print Network

Harvesting ambient vibration energy through piezoelectric means is a popular energy harvesting technique which can potentially supply 10-100's of [mu]W of available power. One of the main limitations of existing piezoelectric ...

Ramadass, Yogesh Kumar

112

The design of low-frequency, low-g piezoelectric micro energy harvesters  

E-print Network

A low-frequency, low-g piezoelectric MEMS energy harvester has been designed. Theoretically, this new generation energy harvester will generate electric power from ambient vibrations in the frequency range of 200~30OHz at ...

Xu, Ruize, S.M. Massachusetts Institute of Technology

2012-01-01

113

Energy Harvesting Diamond Channel with Energy Cooperation  

E-print Network

Energy Harvesting Diamond Channel with Energy Cooperation Berk Gurakan Sennur Ulukus Department@umd.edu Abstract--We consider the energy harvesting diamond channel, where the source and two relays harvest energy the option of wirelessly transferring some of its energy to the relays via energy cooperation. We find

Ulukus, Sennur

114

Enhanced energy harvesting in commercial ferroelectric materials  

NASA Astrophysics Data System (ADS)

Ferroelectric materials are used in a number of applications ranging from simple sensors and actuators to ferroelectric random access memories (FRAMs), transducers, health monitoring system and microelectronics. The multiphysical coupling ability possessed by these materials has been established to be useful for energy harvesting applications. However, conventional energy harvesting techniques employing ferroelectric materials possess low energy density. This has prevented the successful commercialization of ferroelectric based energy harvesting systems. In this context, the present study aims at proposing a novel approach for enhanced energy harvesting using commercially available ferroelectric materials. This technique was simulated to be used for two commercially available piezoelectric materials namely PKI-552 and APCI-840, soft and hard lead-zirconate-titanate (PZT) pervoskite ceramics, respectively. It was observed that a maximum energy density of 348 kJm-3cycle-1 can be obtained for cycle parameters of (0-1 ton compressive stress and 1-25 kV.cm-1 electric field) using APCI-840. The reported energy density is several hundred times larger than the maximum energy density reported in the literature for vibration harvesting systems.

Patel, Satyanarayan; Chauhan, Aditya; Vaish, Rahul

2014-04-01

115

Energy Harvesting Communications with Continuous Energy Arrivals  

E-print Network

Energy Harvesting Communications with Continuous Energy Arrivals Burak Varan Kaya Tutuncuoglu Aylin--This work considers an energy harvesting transmit- ter that gathers a continuous flow of energy from intermittent sources, thus relaxing the modeling assumption of discrete amounts of harvested energy present

Yener, Aylin

116

A Review of Power Harvesting from Vibration Using Piezoelectric Materials  

Microsoft Academic Search

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

Henry A. Sodano; Daniel J. Inman

2004-01-01

117

Energy Cooperation in Energy Harvesting Wireless Communications  

E-print Network

Energy Cooperation in Energy Harvesting Wireless Communications Berk Gurakan1 , Omur Ozel1 , Jing node, a relay node and a destination node where the source and the relay can harvest energy from the nature. Energy required for communication arrives (is harvested) at the transmitter and an unlimited

Ulukus, Sennur

118

Piezoelectric cantilevers energy harvesting in MEMS technique  

NASA Astrophysics Data System (ADS)

Piezoelectric cantilevers energy harvesting made by micro-electromechanical system (MEMS) technology can scavenge power from low-level ambient vibration sources. The developed cantilevers energy harvesting are featured with resonate frequency and power output in microwatt level, which is sufficient to the self-supportive sensors for in-service integrity monitoring of large social and environmental infrastructures at remote locations. In this paper, piezoelectric energy harvesting based on thick-film piezoelectric cantilevers is investigated to resonate at specific frequencies of an external vibration energy source, which creating electrical energy via the piezoelectric effect. Our cantilever device has a multiple structure with a proof mass added to the end. The thick film lead zirconate titanate Pb(Zr,Ti)O3 (PZT) coated on the top of Au/Cr/SiO2/Si substrates by sol-gel-spin method. The thickness of the PZT membrane was up to 2?m and the cantilevers substrates thickness 50?m, wideness 1.5mm, length 4mm. The Au/Ti top electrode is patterned on top of the sol-gel-spin coated PZT thick film in order to employ the d31 mode. The prototype energy generator has a measured performance of 0.74?W effective electrical power, and 4.93 DC output voltages to resistance load. The effect of proof mass, beam shape and damping on the power generating performance are modeled to provide a design guideline for maximum power harvesting from environmentally available low frequency vibrations. A multiple structure cantilever is designed to achieve compactness, low resonant frequency and minimum damping coefficient, simultaneously. This device is promising to support networks of ultra-low-power sensor.

Shang, Yingqi; Qiu, Chengjun; Liu, Hongmei; Chen, Xiaojie; Qu, Wei; Dou, Yanwei

2012-04-01

119

Piezoelectric cantilevers energy harvesting in MEMS technique  

NASA Astrophysics Data System (ADS)

Piezoelectric cantilevers energy harvesting made by micro-electromechanical system (MEMS) technology can scavenge power from low-level ambient vibration sources. The developed cantilevers energy harvesting are featured with resonate frequency and power output in microwatt level, which is sufficient to the self-supportive sensors for in-service integrity monitoring of large social and environmental infrastructures at remote locations. In this paper, piezoelectric energy harvesting based on thick-film piezoelectric cantilevers is investigated to resonate at specific frequencies of an external vibration energy source, which creating electrical energy via the piezoelectric effect. Our cantilever device has a multiple structure with a proof mass added to the end. The thick film lead zirconate titanate Pb(Zr,Ti)O3 (PZT) coated on the top of Au/Cr/SiO2/Si substrates by sol-gel-spin method. The thickness of the PZT membrane was up to 2?m and the cantilevers substrates thickness 50?m, wideness 1.5mm, length 4mm. The Au/Ti top electrode is patterned on top of the sol-gel-spin coated PZT thick film in order to employ the d31 mode. The prototype energy generator has a measured performance of 0.74?W effective electrical power, and 4.93 DC output voltages to resistance load. The effect of proof mass, beam shape and damping on the power generating performance are modeled to provide a design guideline for maximum power harvesting from environmentally available low frequency vibrations. A multiple structure cantilever is designed to achieve compactness, low resonant frequency and minimum damping coefficient, simultaneously. This device is promising to support networks of ultra-low-power sensor.

Shang, Yingqi; Qiu, Chengjun; Liu, Hongmei; Chen, Xiaojie; Qu, Wei; Dou, Yanwei

2011-11-01

120

Plucked piezoelectric bimorphs for energy harvesting applications  

NASA Astrophysics Data System (ADS)

The modern drive towards mobility and wireless devices is motivating intense research in energy harvesting (EH) technologies. In an effort to reduce the battery burden of people, we are investigating a novel piezoelectric wearable energy harvester. As piezoelectric EH is significantly more effective at high frequencies, in opposition to the characteristically low-frequency human activities, we propose the use of an up-conversion strategy analogous to the pizzicato musical technique. In order to guide the design of such harvester, we have modelled with Finite Elements (FE) the response and power generation of a piezoelectric bimorph while it is "plucked", i.e. deflected, then released and permitted to vibrate freely. An experimental rig has been devised and set up to reproduce the action of the bimorph in the harvester. Measurements of the voltage output and the energy dissipated across a series resistor are reported and compared with the FE predictions. As the novel harvester will feature a number of bimorphs, each plucked tens of times per step, we predict a total power output of several mW, with imperceptible effect on the wearer's gait.

Pozzi, Michele; Zhu, Meiling

2011-06-01

121

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

122

Harvesting Energy from Wastewater Treatment  

E-print Network

Harvesting Energy from Wastewater Treatment Bruce Logan Penn State University #12;Energy Costs? 5-7% of electricity used in USA is for water &wastewater #12;Global Energy & Health IssuesGlobal Energy & Health content of WastewatersEnergy content of Wastewaters ·· ElectricityElectricity ""lostlost"" to water

123

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

Microsoft Academic Search

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

Yuantai Hu; Huan Xue; Ting Hu; Hongping Hu

2008-01-01

124

Energy-Neutral Source-Channel Coding in Energy-Harvesting Wireless Sensors  

E-print Network

the energy needed for their operation from the environment, e.g., in the form of solar, vibrational or radio with an instantaneous channel SNR. Based on the statistics of the energy harvesting process, and based on the current1 Energy-Neutral Source-Channel Coding in Energy-Harvesting Wireless Sensors P. Castiglione, O

Zemen, Thomas

125

Harvesting Energy from Wastewater Treatment  

E-print Network

Harvesting Energy from Wastewater Treatment Bruce Logan Penn State University #12;Energy Costs? 5-7% of electricity used in USA is for water &wastewater #12;Global Energy & Health Issues 1 Billion people lack #12;Energy content of Wastewaters · Electricity "lost" to water and wastewater treatment= 0.6 quad

126

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

127

Piezoelectric Energy Harvesting Device Optimization by Synchronous Electric Charge Extraction  

Microsoft Academic Search

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

Elie Lefeuvre; Adrien Badel; Claude Richard; Daniel Guyomar

2005-01-01

128

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

129

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

130

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

131

Sunrise for energy harvesting products  

Microsoft Academic Search

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

J. Krikke

2005-01-01

132

Energy harvesting devices for harvesting energy from terahertz electromagnetic radiation  

DOEpatents

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

Novack, Steven D.; Kotter, Dale K.; Pinhero, Patrick J.

2012-10-09

133

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

134

Switching Delay Effects on Nonlinear Piezoelectric Energy Harvesting Techniques  

Microsoft Academic Search

Energy harvesting using piezoelectric elements re- ceived much attention as vibrations are widely available and as piezoelectric transducers feature high-power densities and promising integration potentials. It has also been shown that applying a nonlinear treatment on the output voltage of the piezo- electric material can significantly enhance the performance of the device. This process consists of inverting the piezoelectric voltage

Mickaël Lallart; Yi-Chieh Wu; Daniel Guyomar

2012-01-01

135

IEEE/ACM TRANS. ON NETWORKING, TO APPEAR 1 Utility Optimal Scheduling in Energy Harvesting  

E-print Network

the environment. For instance, by converting me- chanical vibration into energy [1], by using solar panels [2IEEE/ACM TRANS. ON NETWORKING, TO APPEAR 1 Utility Optimal Scheduling in Energy Harvesting Networks performance in energy harvesting networks with only finite capacity energy storage devices. In these networks

Huang, Longbo

136

Optimal Sleep-Wake Scheduling for Energy Harvesting Smart Mobile Devices  

E-print Network

], by converting mechanical vibration into energy [4], or by using solar panels [5]. These newly developed energyOptimal Sleep-Wake Scheduling for Energy Harvesting Smart Mobile Devices Longbo Huang Institute capacity batteries and are capable of harvesting energy from the environment. Using a novel combination

Huang, Longbo

137

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

138

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

139

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

140

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

NASA Astrophysics Data System (ADS)

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

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

2010-04-01

141

Energy Harvesting Broadcast Channel with Inefficient Energy Storage  

E-print Network

Energy Harvesting Broadcast Channel with Inefficient Energy Storage Kaya Tutuncuoglu Aylin Yener with an energy harvesting transmitter equipped with an inefficient energy storage device. For this setting by the energy harvesting process. The convexity of the capacity region for the energy harvesting broadcast

Yener, Aylin

142

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

143

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

144

Piezoelectric capacitive power generator from vibration energy  

NASA Astrophysics Data System (ADS)

A vibration-powered micro-power-generator has been presented in this paper, which has integrated two different energy harvesting mechanisms, e.g., Capacitive and Piezoelectric Mechanisms. The periodic vibration of the mass on movable electrode causes the variation of the capacitance, and the strain in the piezoelectric film. These two mechanisms can harvest the vibration energy and generate current in the output circuit. By using two different metals with large difference in working function as the two electrodes of the capacitor, our design, the combination of these two different scavenge mechanisms, can overcome the dependence of the traditional capacitive converter on the separate voltage source and improve the efficiency of power conversion. The volume of the designed device is less than 0.8 cm 3. The simulated results reveal that this energy converter can provide an average output power of 82.21?W at an external vibration with a frequency of 111.4 Hz and amplitude of 0.2g.

Zhang, Yangjian; Li, Lin; San, Haisheng; Chen, Xuyuan

2008-03-01

145

Scheduling with Quality of Service requirements in Real-Time Energy Harvesting sensors  

E-print Network

electronics, homes, cars, wearable devices, etc. Consequently, research is very active for designing both very for a solar-powered system. Possible energy harvesting sources are solar, thermal, vibrational and kinetic

Paris-Sud XI, Université de

146

Power management in energy harvesting sensor networks  

Microsoft Academic Search

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

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

2007-01-01

147

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

Microsoft Academic Search

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

Steven R. Anton; Daniel J. Inman

2011-01-01

148

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

149

Vibrational Beatings Conceal Evidence of Electronic Coherence in the FMO Light-Harvesting Complex.  

PubMed

In biological light harvesting, solar energy is captured by photosynthetic antennae for subsequent storage into chemical bonds. The remarkable efficiency reached in transferring the energy between the collection and storage events recently has been attributed to long-lived electronic coherence present in such antennae systems. We present numerical simulations indicating that the spectroscopic transients that supported this hypothesis are not induced by electronic coherence but instead are caused by vibrational (nuclear) motion in the electronic ground state potential. Besides emphasizing the significance of such nuclear modes, our findings stimulate a reconsideration of the role of electronic coherence in promoting energy transfer in natural photosynthesis. Furthermore, they require us to rethink how energy transfer efficiency is reflected in spectral signals. PMID:25321492

Tempelaar, Roel; Jansen, Thomas L C; Knoester, Jasper

2014-11-13

150

Enhanced Acoustic Energy Harvesting Using Coupled Resonance Structure of Sonic Crystal and Helmholtz Resonator  

NASA Astrophysics Data System (ADS)

An acoustic energy harvester using a coupled resonance structure of a sonic crystal resonator and an electromechanical Helmholtz resonator with a piezoelectric composite diaphragm is proposed to enhance energy harvesting. Due to acoustic resonance coupling between the sonic crystal resonator and the Helmholtz resonator, the coupled resonance structure has a larger acoustic pressure magnification than each individual resonator structure. Consequently, the stronger vibration of the diaphragm and the higher harvesting efficiency are obtained. Experimental results show that the proposed harvester exhibits ?23 and ?262 times higher maximum harvesting efficiencies than the sonic crystal resonator and the Helmholtz resonator structure, respectively.

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

2013-12-01

151

Investigations of biomimetic light energy harvesting pigments  

SciTech Connect

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

152

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

2012-04-01

153

Energy Harvesting Communications with Hybrid Energy Storage and Processing Cost  

E-print Network

Energy Harvesting Communications with Hybrid Energy Storage and Processing Cost Omur Ozel Khurram with an energy harvesting transmitter with non-negligible processing circuitry power and a hybrid energy storage for energy storage while the battery has unlimited space. The transmitter stores the harvested energy either

Ulukus, Sennur

154

On thermoelectric and pyroelectric energy harvesting  

Microsoft Academic Search

This paper deals with small-power energy harvesting from heat. It can be achieved using both thermoelectric and pyroelectric effects. In the first case, temperature gradients are necessary. The main difficulty of thermoelectric energy harvesting is imposing a large temperature gradient. This requires huge heat flows because of the limited surface heat exchanges and the large heat conductivity of thermoelectric materials.

Gael Sebald; Daniel Guyomar; Amen Agbossou

2009-01-01

155

Afternoon Session-Part 1 Energy Harvesting  

E-print Network

/27/2011Wireless Information Theory Summer School in Oulu, Finland 7 Image Credits: (left) http://inhabitat.com/shoe Design Challenge: A set of energy feasibility constraints based on harvests govern the communication resources. Design question: When and at what rate/power should a "rechargeable" (energy harvesting) node

Ulukus, Sennur

156

Optimal Energy-Bandwidth Allocation for Energy Harvesting Interference Networks  

E-print Network

Optimal Energy-Bandwidth Allocation for Energy Harvesting Interference Networks Zhe Wang, Vaneet@research.att.com Abstract--We develop optimal energy-bandwidth allocation algorithm for the energy harvesting transmitters in interference networks. We assume that both the channel gain and the harvested energy are known for K slots

Fisher, Kathleen

157

The Energy Harvesting Multiple Access Channel with Energy Storage Losses  

E-print Network

The Energy Harvesting Multiple Access Channel with Energy Storage Losses Kaya Tutuncuoglu and Aylin considers a Gaussian multiple access channel with two energy harvesting transmitters with lossy energy storage. The power allocation policy maximizing the average weighted sum rate given the energy harvesting

Yener, Aylin

158

Power harvesting and management from vibrations: a multi-source strategy simulation for aircraft structure health monitoring  

NASA Astrophysics Data System (ADS)

Vibration harvesting has been intensively developed recently and systems have been simulated and realized, but real-life situations (including aircraft Structure Health Monitoring (SHM)involve uneven, low amplitude, low frequency vibrations. In such an unfavorable case, it is very likely that no power can be harvested for a long time. To overcome this, multi-source harvesting is a relevant solution, and in our application both solar and thermal gradient sources are available. We propose in this paper a complete Microsystem including a piezoelectric vibration harvesting module, thermoelectric conversion module, signal processing electronics and supercapacitor. A model is proposed for these elements and a VHDL-AMS simulation of the whole system is presented, showing that the vibration harvesting device alone cannot supply properly a SHM wireless node. Its role is nevertheless important since it is a more reliable source than thermoelectric (which depends on climatic conditions). Moreover, synergies between vibration harvesting and thermoelectric scavenging circuits are presented.

Durou, Hugo; Rossi, Carole; Brunet, Magali; Vanhecke, Claude; Bailly, Nicolas; Ardila, Gustavo; Ourak, Lamine; Ramond, Adrien; Simon, Patrice; Taberna, Pierre-Louis

2008-12-01

159

Vibration-to-electric energy conversion using a mechanically-varied capacitor  

E-print Network

Past research in vibration energy harvesting has focused on the use of variable capacitors, magnets, or piezoelectric materials as the basis of energy transduction. How- ever, few of these studies have explored the detailed ...

Yen, Bernard Chih-Hsun, 1981-

2005-01-01

160

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

161

Flow energy harvesting -- another application of the biomimetic flapping foils  

NASA Astrophysics Data System (ADS)

Imitating fish fins and insect wings, flapping foils are usually used for biomimetic propulsion. Theoretical studies and experiments have demonstrated that through specific combinations of heaving and pitching motions, these foils can also extract energy from incoming wind or current. Compared with conventional flow energy harvesting devices based upon rotating turbines, this novel design promises mitigated impact upon the environment. To achieve the required motions, existing studies focus on hydrodynamic mode coupling, in which a periodic pitching motion is activated and a heaving motion is then generated by the oscillating lifting force. Energy extraction is achieved through a damper in the heaving direction (representing the generator). This design involves a complicated control and activation system. In addition, there is always the possibility that the energy required to activate the system exceeds the energy recovered by the generator. We have discovered that a much simpler device without activation, a 2DOF foil mounted on a rotational spring and a damper undergoing flow-induced motions can achieve stable flow energy harvesting. Using Navier-Stokes simulations we predicted different behaviors of the system during flow-induced vibrations and identified the specific requirements to achieve controllable periodic motions essential for stable energy harvesting. The energy harvesting capacity and efficiency were also determined.

Zhu, Qiang; Peng, Zhangli

2009-11-01

162

Piezoelectric energy harvesting from transverse galloping of bluff bodies  

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

163

An aero-elastic flutter based electromagnetic energy harvester with wind speed augmenting funnel  

E-print Network

An aero-elastic flutter based electromagnetic energy harvester with wind speed augmenting funnel been used to convert wind flow energy into mechanical vibration, which is then transformed-scale renewable energy generating systems such as wind turbines, thermal generators, and solar panels, energy

Stanford University

164

Ultra-wide bandwidth piezoelectric energy harvesting  

E-print Network

Here, we present an ultra wide-bandwidth energy harvester by exploiting the nonlinear stiffness of a doubly clamped microelectromechanical systems (MEMSs) resonator. The stretching strain in a doubly clamped beam shows a ...

Hajati, Arman

165

Harvesting traffic-induced vibrations for structural health monitoring of bridges  

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

166

Development of a biomechanical energy harvester  

Microsoft Academic Search

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

Qingguo Li; Veronica Naing; J Maxwell Donelan

2009-01-01

167

Broadband energy harvesting via magnetic coupling between two movable magnets  

NASA Astrophysics Data System (ADS)

Harvesting energy from ambient mechanical vibrations by the piezoelectric effect has been proposed for powering microelectromechanical systems and replacing batteries that have a finite life span. A conventional piezoelectric energy harvester (PEH) is usually designed as a linear resonator, and suffers from a narrow operating bandwidth. To achieve broadband energy harvesting, in this paper we introduce a concept and describe the realization of a novel nonlinear PEH. The proposed PEH consists of a primary piezoelectric cantilever beam coupled to an auxiliary piezoelectric cantilever beam through two movable magnets. For predicting the nonlinear response from the proposed PEH, lumped parameter models are established for the two beams. Both simulation and experiment reveal that for the primary beam, the introduction of magnetic coupling can expand the operating bandwidth as well as improve the output voltage. For the auxiliary beam, the magnitude of the output voltage is slightly reduced, but additional output is observed at off-resonance frequencies. Therefore, broadband energy harvesting can be obtained from both the primary beam and the auxiliary beam.

Fan, Kang-Qi; Xu, Chun-Hui; Wang, Wei-Dong; Fang, Yang

2014-08-01

168

Optimal design of piezoelectric materials and devices for energy harvesting  

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

169

Utility-based Time and Power Allocation on an Energy Harvesting Downlink: The Optimal  

E-print Network

problem where the transmitter is aware of the energy arrival statistics of a frame before the frame starts advances in the areas of solar, piezoelectric and thermal energy har- vesting, enable systems harvest energy through solar cells, vibration absorption devices, thermoelectric generators, wind power

Uysal-Biyikoglu, Elif

170

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

171

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

172

Seebeck nanoantennas for solar energy harvesting  

NASA Astrophysics Data System (ADS)

We propose a mid-infrared device based on thermocouple optical antennas for light sensing and energy harvesting applications. We numerically demonstrate that antennas are able to generate low-power dc signals by beneficing of the thermoelectric properties of the metals that constitute them. We theoretically evaluate the optical-to-electrical conversion efficiency for harvesting applications and finally discuss strategies to increase its performance. Thermocouple optical antennas therefore open the route toward the design of photovoltaic devices.

Briones, E.; Briones, J.; Cuadrado, A.; Martinez-Anton, J. C.; McMurtry, S.; Hehn, M.; Montaigne, F.; Alda, J.; Gonzalez, F. J.

2014-09-01

173

Optimizing the dielectric elastomer energy harvesting cycles  

Microsoft Academic Search

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

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

2010-01-01

174

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

175

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

176

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

NASA Astrophysics Data System (ADS)

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

Li, Jingcheng; Jang, Shinae; Tang, Jiong

2012-04-01

177

Thermal energy harvesting plasmonic based chemical sensors.  

PubMed

Detection of gases such as H2, CO, and NO2 at 500 °C or greater requires materials with thermal stability and reliability. One of the major barriers toward integration of plasmonic-based chemical sensors is the requirement of multiple components such as light sources and spectrometers. In this work, plasmonic sensing results are presented where thermal energy is harvested using lithographically patterned Au nanorods, replacing the need for an external incident light source. Gas sensing results using the harvested thermal energy are in good agreement with sensing experiments, which used an external incident light source. Principal Component Analysis (PCA) was used to reduce the wavelength parameter space from 665 variables down to 4 variables with similar levels of demonstrated selectivity. The combination of a plasmonic-based energy harvesting sensing paradigm with PCA analysis offers a novel path toward simplification and integration of plasmonic-based sensing methods. PMID:25280004

Karker, Nicholas; Dharmalingam, Gnanaprakash; Carpenter, Michael A

2014-10-28

178

Resource Management and Scheduling in WSNs Powered by Ambient Energy Harvesting  

E-print Network

], vibrational [13], [18], wind [30] and thermal energy [29]) to replace/supplement batteries that power WSNsResource Management and Scheduling in WSNs Powered by Ambient Energy Harvesting Neyre Tekbiyik wireless sensor networks (WSNs) brings several advantages over traditional wired systems, including self

Uysal-Biyikoglu, Elif

179

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

Microsoft Academic Search

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

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

2010-01-01

180

Acoustic energy harvesting using an electromechanical Helmholtz resonator.  

PubMed

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

181

Electromagnetic ferrofluid-based energy harvester  

NASA Astrophysics Data System (ADS)

This Letter investigates the use of ferrofluids for vibratory energy harvesting. In particular, an electromagnetic micro-power generator which utilizes the sloshing of a ferrofluid column in a seismically-excited tank is proposed to transform mechanical motions directly into electricity. Unlike traditional electromagnetic generators that implement a solid magnet, ferrofluids can easily conform to different shapes and respond to very small acceleration levels offering an untapped opportunity to design scalable energy harvesters. The feasibility of the proposed concept is demonstrated and its efficacy is discussed through several experimental studies.

Bibo, A.; Masana, R.; King, A.; Li, G.; Daqaq, M. F.

2012-06-01

182

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

183

Fabrication techniques and performance of piezoelectric energy harvesters  

Microsoft Academic Search

Energy harvesting devices which convert ambient energy to electrical energy has attracted a lot of attention in commercial sectors. Due to the environmental consciousness, energy harvesting devices or so called micro generators promise a cleaner environment by avoiding the usage of batteries. Piezoelectric energy harvesters are the most promising solution because they can efficiently convert mechanical strain to electrical charge

A. A. M. Ralib; A. Nurashikin; H. Salleh

2009-01-01

184

Electronic resonance with anticorrelated pigment vibrations drives photosynthetic energy transfer outside the adiabatic framework  

PubMed Central

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.

2013-01-01

185

Power management circuit for resonant energy harvesters  

NASA Astrophysics Data System (ADS)

This paper deals with the design of the power management circuit for the vibration generator developed in the frame of the European WISE project and its testing in the connection with the generator and the dynamic load simulating the real load. This generator is used as an autonomous energy source for wireless sensor applications. It can be used for example in the aeronautic, automotive and many other applications. The generator output power analysis was based on the vibration spectrum measured on the helicopter engine, provided by the consortium EADS, EUROCOPTER, DASSAULT AVIATION - 6.RP -WIreless SEnsing (WISE) project. This spectrum shows very unstable vibration levels. It was done the statistical analysis of these vibration levels and it was shown that there is a need of the power management circuit, which can provide a stable output voltage for the supplied circuit and if there is a need it can store an immediately unusable generated energy. The generator can't be used as the only energy source for the sensor circuit, because there are not any vibrations when for example a motor is stopped. In these periods and in the time of low vibration levels the circuit must be supplied from battery. The power management circuit described in this paper fulfills these requirements. It has two power inputs - the battery and the generator. It can switch between them at certain defined generator output levels by the threshold detector. Also when there is too much of the generated power, it can store the extra energy in the storage for the later usage. The storage device is the advanced capacitor. The advanced capacitor is a device containing three capacitors. These capacitors are connected (and charged) sequentially so the increasing capacity is provided. The developed power management was tested in the connection with the real vibration generator raised by stable vibration levels and the dynamic load simulating the real sensor in the main operation stages - sampling and data transmitting. It was shown that the generator with output power of 8mW@0,3GRMS with generator weight of 140g together with the described power management circuit can save about 50% of battery energy with the mentioned vibration spectrum. The generator used for the testing was improved, so it is more sensitive and also the sensor power requirements were decreased, so now it can be saved up to 100% battery energy during the generator operation. Also the power management circuit is still refined.

Jirku, Tomas; Steinbauer, Miloslav; Kluge, Martin

2009-05-01

186

ENERGY HARVESTING UTILISING THE GYROSCOPIC EFFECT  

E-print Network

ENERGY HARVESTING UTILISING THE GYROSCOPIC EFFECT N.C. Townsend nick@soton.ac.uk Fluid Structure of a marine vessel can induce gyroscopic precession. x y Z 0 Figure 1: A Schematic of a Single Unit Gyroscopic the gyroscopic effect) Experimental sea trials will be conducted in 2011. The motivation behind the project

Sóbester, András

187

FR4-based electromagnetic energy harvester for wireless sensor nodes  

NASA Astrophysics Data System (ADS)

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

Hatipoglu, G.; Ürey, H.

2010-01-01

188

Active Piezoelectric Energy Harvesting: General Principle and Experimental Demonstration  

Microsoft Academic Search

In piezoelectric energy harvesting systems, the energy harvesting circuit is the interface between a piezoelectric device and an electrical load. A conventional view of this interface is based on impedance matching concepts. In fact, an energy harvesting circuit can also apply electrical boundary conditions, such as voltage and charge, to the piezoelectric device for each energy conversion cycle. An optimized

Yiming Liu; Geng Tian; Yong Wang; Junhong Lin; Qiming Zhang; Heath F. Hofmann

2009-01-01

189

Network-Level Cooperation in Energy Harvesting Wireless Nikolaos Pappas*  

E-print Network

with energy harvesting source and relay. I. INTRODUCTION Taking advantage of renewable energy resources from, acoustic, wind, and even ambient radio power. However, the additional functionality of harvesting energyNetwork-Level Cooperation in Energy Harvesting Wireless Networks Nikolaos Pappas* , Marios

Paris-Sud XI, Université de

190

An energy management framework for energy harvesting embedded systems  

Microsoft Academic Search

Energy harvesting (also known as energy scavenging) is the process of generating electrical energy from environmental energy sources. There exists a variety of different energy sources such as solar energy, kinetic energy, or thermal energy. In recent years, this term has been frequently applied in the context of small autonomous devices such as wireless sensor nodes. In this article, a

Clemens Moser; Jian-Jia Chen; Lothar Thiele

2010-01-01

191

Variable entropy solar energy harvester  

SciTech Connect

A collector of solar energy has, in cross-section, the profile of a nested, truncated and inverted trough which is formed as an array of concentric annular conic frusta. The array ascends from a base, defined by the outermost frustum, to a vertex defined by the innermost frustum. The collector is disposed intermediate the sun and an absorber of solar energy. The collector is operatively connected with sun-tracking means for movement in a predetermined direction and through a predetermined distance relative to the center of the remote absorber. The frusta have reflective inner surfaces, each of which is defined by a singular and unique parabola. Light incident upon the surfaces is transmitted by a single reflection, through the openings at the base of the trough, onto a common focus located at the absorber for the optimal concentration of the collected radiation which may be utilized as thermal energy or converted into other useful forms of energy.

York, B.H.

1982-09-07

192

Acoustic energy harvesting by piezoelectric curved beams in the cavity of a sonic crystal  

Microsoft Academic Search

Acoustic energy harvesting by piezoelectric curved beams in the cavity of a sonic crystal is investigated. A resonant cavity of the sonic crystal is used to localize the acoustic wave as the acoustic waves are incident into the sonic crystal at the resonant frequency. The piezoelectric curved beam is placed in the resonant cavity and vibrated by the acoustic wave.

Wei-Chung Wang; Liang-Yu Wu; Lien-Wen Chen; Chia-Ming Liu

2010-01-01

193

SensEH: From Simulation to Deployment of Energy Harvesting Wireless Sensor Networks  

E-print Network

used for adaptive lighting in road tunnels can be extended using harvesters based on photovoltaic panels. I. INTRODUCTION The market value of wireless sensor networks (WSNs) is growing steadily problem. Indeed, in many cases the energy density--whether solar, wind, vibrational or thermal in nature

Picco, Gian Pietro

194

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

Microsoft Academic Search

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

Daniel Guyomar; Adrien Badel; Elie Lefeuvre; Claude Richard

2005-01-01

195

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

196

Energy-harvesting at the Nanoscale  

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

197

Delay Optimal Scheduling for Energy Harvesting Based Communications  

E-print Network

. Equipped with a rechargeable battery, a source node can harvest energy from ambient environments and rely by a capacity-limited battery storing harvested energy and the grid. The proposed scheduling scheme would give be substantially extended. Energy harvesting can also help to reduce carbon emission and envi- ronmental pollution

Dai, Huaiyu

198

Multi-physics model of a thermo-magnetic energy harvester  

NASA Astrophysics Data System (ADS)

Harvesting small thermal gradients effectively to generate electricity still remains a challenge. Ujihara et al (2007 Appl. Phys. Lett. 91 093508) have recently proposed a thermo-magnetic energy harvester that incorporates a combination of hard and soft magnets on a vibrating beam structure and two opposing heat transfer surfaces. This design has many advantages and could present an optimum solution to harvest energy in low temperature gradient conditions. In this paper, we describe a multi-physics numerical model for this harvester configuration that incorporates all the relevant parameters, including heat transfer, magnetic force, beam vibration, contact surface and piezoelectricity. The model was used to simulate the complete transient behavior of the system. Results are presented for the evolution of the magnetic force, changes in the internal temperature of the soft magnet (gadolinium (Gd)), thermal contact conductance, contact pressure and heat transfer over a complete cycle. Variation of the vibration frequency with contact stiffness and gap distance was also modeled. Limit cycle behavior and its bifurcations are illustrated as a function of device parameters. The model was extended to include a piezoelectric energy harvesting mechanism and, using a piezoelectric bimorph as spring material, a maximum power of 318 ?W was predicted across a 100 k? external load.

Joshi, Keyur B.; Priya, Shashank

2013-05-01

199

Flexible piezoelectric energy harvesting from jaw movements  

NASA Astrophysics Data System (ADS)

Piezoelectric fiber composites (PFC) represent an interesting subset of smart materials that can function as sensor, actuator and energy converter. Despite their excellent potential for energy harvesting, very few PFC mechanisms have been developed to capture the human body power and convert it into an electric current to power wearable electronic devices. This paper provides a proof of concept for a head-mounted device with a PFC chin strap capable of harvesting energy from jaw movements. An electromechanical model based on the bond graph method is developed to predict the power output of the energy harvesting system. The optimum resistance value of the load and the best stretch ratio in the strap are also determined. A prototype was developed and tested and its performances were compared to the analytical model predictions. The proposed piezoelectric strap mechanism can be added to all types of head-mounted devices to power small-scale electronic devices such as hearing aids, electronic hearing protectors and communication earpieces.

Delnavaz, Aidin; Voix, Jérémie

2014-10-01

200

Energy Cooperation in Energy Harvesting Two-Way Communications  

E-print Network

Energy Cooperation in Energy Harvesting Two-Way Communications Berk Gurakan1 , Omur Ozel1 , Jing energy from nature and energy can be transferred in one-way from one of the users to the other. Energy and users have unlimited batteries to store energy for future use. In addition, there is a separate wireless

Ulukus, Sennur

201

Energy-harvesting linear MR damper: prototyping and testing  

NASA Astrophysics Data System (ADS)

The present study is concerned with an energy-harvesting linear MR (EH-LMR) damper which is able to recover energy from external excitations using an electromagnetic energy extractor, and to adjust itself to excitations by varying the damping characteristics. The device has three main components: an MR part having a damper piston assembly movable in relation to the damper cylinder under an external excitation, a power generator to produce electrical power according to the relative movement between the damper piston and the cylinder assembly, and a conditioning electronics unit to interface directly with the generator and the MR damper. The EH-LMR damper integrates energy harvesting, dynamic sensor and MR damping technologies in a single device. The objective of the study is to get a better insight into the structure of EH-LMR damper components, to investigate the performance of each component and a device as a whole, and to compare results of experimental study against numerical data obtained in simulations conducted at the design stage. The research work demonstrates that the proposed EH-LMR damper provides a smart and compact solution with the potential of application to vibration isolation. The advantage of the device is its adaptability to external excitations and the fact that it does not need any extra power supply unit or sensor on account of its self-powered and self-sensing capabilities.

Sapi?ski, Bogdan

2014-03-01

202

Consideration of impedance matching techniques for efficient piezoelectric energy harvesting.  

PubMed

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

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

2007-09-01

203

Development of a biomechanical energy harvester  

PubMed Central

Background Biomechanical energy harvesting–generating electricity from people during daily activities–is a promising alternative to batteries for powering increasingly sophisticated portable devices. We recently developed a wearable knee-mounted energy harvesting device that generated electricity during human walking. In this methods-focused paper, we explain the physiological principles that guided our design process and present a detailed description of our device design with an emphasis on new analyses. Methods Effectively harvesting energy from walking requires a small lightweight device that efficiently converts intermittent, bi-directional, low speed and high torque mechanical power to electricity, and selectively engages power generation to assist muscles in performing negative mechanical work. To achieve this, our device used a one-way clutch to transmit only knee extension motions, a spur gear transmission to amplify the angular speed, a brushless DC rotary magnetic generator to convert the mechanical power into electrical power, a control system to determine when to open and close the power generation circuit based on measurements of knee angle, and a customized orthopaedic knee brace to distribute the device reaction torque over a large leg surface area. Results The device selectively engaged power generation towards the end of swing extension, assisting knee flexor muscles by producing substantial flexion torque (6.4 Nm), and efficiently converted the input mechanical power into electricity (54.6%). Consequently, six subjects walking at 1.5 m/s generated 4.8 ± 0.8 W of electrical power with only a 5.0 ± 21 W increase in metabolic cost. Conclusion Biomechanical energy harvesting is capable of generating substantial amounts of electrical power from walking with little additional user effort making future versions of this technology particularly promising for charging portable medical devices. PMID:19549313

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

2009-01-01

204

Harvesting Residuals-Economic Energy Link  

E-print Network

and unmerchantable trees is outlined for three areas in New Brunswick, Canada. The silvicultural benefits and the use of residues as an alternative to fossil fuels are the reasons for of overcoming the normally unfavorable producing residues... fossil fuels and wood are reflected in the integrated harvesting of all trees and the establishment of the new forest. During the past two decades there has been a growing demand for wood-for-energy. The residues from sawmills increasingly were being...

Owens, E. T.; Curtis, D. B.

205

Nonlinear mechanism in MEMS devices for energy harvesting applications This article has been downloaded from IOPscience. Please scroll down to see the full text article.  

E-print Network

Nonlinear mechanism in MEMS devices for energy harvesting applications This article has been.1088/0960-1317/20/12/125020 Nonlinear mechanism in MEMS devices for energy harvesting applications B And`o1, S Baglio1, C Trigona1, N. In particular, we focus here on methodologies and devices for recovering energy from mechanical vibrations

Paris-Sud XI, Université de

206

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

207

Environmental effects of harvesting forests for energy  

SciTech Connect

Present interest in decreasing US dependence on foreign oil by increasing the use of wood for energy may bring about a change in our forest utilization policies. In the past, forests have been removed in areas believed to be suited for agriculture, or sawtimber and pulp have been the only woody material removed in any quantity from land not generally considered tillable. The new demands on wood for energy are effecting a trend toward (1) removing all woody biomass from harvested areas, (2) increasing the frequency of harvesting second growth forests, and (3) increasing production with biomass plantations. Considering the marginal quality of much of the remaining forested land, the impacts of these modes of production could be significant. For example, it is anticipated that increased losses of nutrients and carbon will occur by direct forest removal and through erosion losses accelerated by forest clearing. There are, however, control measures that can be utilized in minimizing both direct and indirect effects of forest harvesting while maximizing woody biomass production.

Van Hook, R.I.; Johnson, D.W.; West, D.C.; Mann, L.K.

1980-01-01

208

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

E-print Network

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

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

2012-03-20

209

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

PubMed

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

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

2012-11-01

210

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

NASA Astrophysics Data System (ADS)

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

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

2012-11-01

211

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

212

Nonlinear analysis and enhancement of wing-based piezoaeroelastic energy harvesters  

NASA Astrophysics Data System (ADS)

We investigate the level of harvested power from aeroelastic vibrations for an elastically mounted wing supported by nonlinear springs. The energy is harvested by attaching a piezoelectric transducer to the plunge degree of freedom. The considered wing has a low-aspect ratio and hence three dimensional aerodynamic effects cannot be neglected. To this end, the three dimensional unsteady vortex lattice method for the prediction of the unsteady aerodynamic loads is developed. A strong coupling scheme that is based on Hamming's fourth-order predictor-corrector method and accounts for the interaction between the aerodynamic loads and the motion of the wing is employed. The effects of the electrical load resistance, nonlinear torsional spring and eccentricity between the elastic axis and the gravity axis on the level of the harvested power, pitch and plunge amplitudes are investigated for a range of operating wind speeds. The results show that there is a specific wind speed beyond which the pitch motion does not pick any further energy from the incident flow. As such, the displacement in the plunge direction grows significantly and causes enhanced energy harvesting. The results also show that the nonlinear torsional spring plays an important role in enhancing the level of the harvested power. Furthermore, the harvested power can be increased by an order of magnitude by properly choosing the eccentricity and the load resistance. This analysis is helpful in designing piezoaeroelastic energy harvesters that can operate optimally at specific wind speeds.

Abdelkefi, A.; Ghommem, M.; Nuhait, A. O.; Hajj, M. R.

2014-01-01

213

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

2010-04-01

214

Improved Performances of Acoustic Energy Harvester Fabricated Using Sol/Gel Lead Zirconate Titanate Thin Film  

NASA Astrophysics Data System (ADS)

Energy harvesters integrable on smart sensor systems have been strongly demanded. Microelectromechanical system (MEMS) acoustic energy harvesters using the first resonance vibration of a lead zirconate titanate (PZT) thin film as a diaphragm have recently been reported. Similar acoustic energy harvesters using the third resonance of a PZT diaphragm fabricated by sol/gel PZT thin film processes exhibited improved generated power density, and it was suggested that the PZT acoustic energy harvester might be suitable for use as a possible power source for silicon integrated circuits. We present further improved power generation performances of PZT MEMS acoustic energy harvesters fabricated by improved PZT capacitor fabrication processes. The PZT acoustic energy harvester with the diaphragm diameter of 1.2 mm fabricated by a sol/gel process generated an even higher energy density of 98 µW/m2 under the sound pressure level of 100 dB (0.01 W/m2) at 16.7 kHz.

Kimura, Shu; Tomioka, Syungo; Iizumi, Satoshi; Tsujimoto, Kyohei; Sugou, Tomohisa; Nishioka, Yasushiro

2011-06-01

215

Jumping-droplet electrostatic energy harvesting  

NASA Astrophysics Data System (ADS)

Micro- and nanoscale wetting phenomena have been an active area of research due to its potential for improving engineered system performance involving phase change. With the recent advancements in micro/nanofabrication techniques, structured surfaces can now be designed to allow condensing coalesced droplets to spontaneously jump off the surface due to the conversion of excess surface energy into kinetic energy. In addition to being removed at micrometric length scales (˜10 ?m), jumping water droplets also attain a positive electrostatic charge (˜10-100 fC) from the hydrophobic coating/condensate interaction. In this work, we take advantage of this droplet charging to demonstrate jumping-droplet electrostatic energy harvesting. The charged droplets jump between superhydrophobic copper oxide and hydrophilic copper surfaces to create an electrostatic potential and generate power during formation of atmospheric dew. We demonstrated power densities of ˜15 pW/cm2, which, in the near term, can be improved to ˜1 ?W/cm2. This work demonstrates a surface engineered platform that promises to be low cost and scalable for atmospheric energy harvesting and electric power generation.

Miljkovic, Nenad; Preston, Daniel J.; Enright, Ryan; Wang, Evelyn N.

2014-07-01

216

Investigation of an energy harvesting small unmanned air vehicle  

NASA Astrophysics Data System (ADS)

The addition of energy harvesting is investigated to determine the benefits of its integration into a small unmanned air vehicle (UAV). Specifically, solar and piezoelectric energy harvesting techniques were selected and their basic functions analyzed. The initial investigation involved using a fundamental law of thermodynamics, entropy generation, to analyze the small UAV with and without energy harvesting. A notional mission was developed for the comparison that involved the aircraft performing a reconnaissance mission. The analysis showed that the UAV with energy harvesting generated less entropy. However, the UAV without energy harvesting outperformed the other UAV in total flight time at the target. The analysis further looked at future energy harvesting technologies and their effect on the energy harvesting UAV to conduct the mission. The results of the mission using the advanced solar technology showed that the effectiveness of the energy harvesting vehicle would increase. Designs for integrating energy harvesting into the small UAV system were also developed and tests were conducted to show how the energy harvesting designs would perform. It was demonstrated that the addition of the solar and piezoelectric devices would supply usable power for charging batteries and sensors and that it would be advantageous to implement them into a small UAV.

Magoteaux, Kyle C.; Sanders, Brian; Sodano, Henry A.

2008-03-01

217

Energy harvesting from harmonic and noise excitation of multilayer piezoelectric stacks: modeling and experiment  

NASA Astrophysics Data System (ADS)

This article theoretically and experimentally studies deterministic and stochastic piezoelectric energy harvesting using a multilayer stack configuration for civil infrastructure system applications that involve large compressive loads, such as vehicular and foot loads acting upon pavements. Modeling of vibrational energy harvesters has been mostly focused on deterministic forms of mechanical excitation as in the typical case of harmonic excitation. In this paper, we present analytical and numerical modeling of piezoelectric energy harvesting from harmonic and random vibrations of multilayer piezoelectric stacks under axial compressive loading. The analytical electromechanical solution is based on the power spectral density (PSD) of random excitation and the voltage - to - pressure input frequency response function (FRF) of the harvester. The first one of the two numerical solution methods employs the Fourier series representation of the vibrational excitation history to solve the resulting ordinary differential equation (ODE), while the second method uses an Euler-Maruyama scheme to directly solve the governing electromechanical stochastic differential equation (SDE). The electromechanical model is validated through several experiments for a multilayer PZT-5H stack under harmonic and random excitations. The analytical predictions and numerical simulations exhibit very good agreement with the experimental measurements for a range of resistive loads and input excitation levels.

Zhao, S.; Erturk, A.

2013-04-01

218

Stretchable energy-harvesting tactile electronic skin capable of differentiating multiple mechanical stimuli modes.  

PubMed

The first stretchable energy-harvesting electronic-skin device capable of differentiating and generating energy from various mechanical stimuli, such as normal pressure, lateral strain, bending, and vibration, is presented. A pressure sensitivity of 0.7 kPa(-1) is achieved in the pressure region <1 kPa with power generation of tens of ?W cm(-2) from a gentle finger touch. PMID:25256696

Park, Steve; Kim, Hyunjin; Vosgueritchian, Michael; Cheon, Sangmo; Kim, Hyeok; Koo, Ja Hoon; Kim, Taeho Roy; Lee, Sanghyo; Schwartz, Gregory; Chang, Hyuk; Bao, Zhenan

2014-11-01

219

Micro energy harvesting for biomedical applications: A review  

Microsoft Academic Search

Energy Harvesting is the process of extracting small amount of energy from ambient environment. Reduction in size and shape of the electronic components make the power requirements down to the scale of mW. Due to this fact, Energy harvesting techniques and their applications gain much more attraction. Many techniques are being developed to gain energy from various available sources viz.

Manisha R. Mhetre; Namrata S. Nagdeo; H. K. Abhyankar

2011-01-01

220

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 Bi IITe 3 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

2006-03-01

221

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

222

Piezoelectric energy harvesting: State-of-the-art and challenges  

NASA Astrophysics Data System (ADS)

Piezoelectric energy harvesting has attracted wide attention from researchers especially in the last decade due to its advantages such as high power density, architectural simplicity, and scalability. As a result, the number of studies on piezoelectric energy harvesting published in the last 5 years is more than twice the sum of publications on its electromagnetic and electrostatic counterparts. This paper presents a comprehensive review on the history and current state-of-the art of piezoelectric energy harvesting. A brief theory section presents the basic principles of piezoelectric energy conversion and introduces the most commonly used mechanical architectures. The theory section is followed by a literature survey on piezoelectric energy harvesters, which are classified into three groups: (i) macro- and mesoscale, (ii) MEMS scale, and (iii) nanoscale. The size of a piezoelectric energy harvester affects a variety of parameters such as its weight, fabrication method, achievable power output level, and potential application areas. Consequently, size-based classification provides a reliable and effective basis to study various piezoelectric energy harvesters. The literature survey on each scale group is concluded with a summary, potential application areas, and future directions. In a separate section, the most prominent challenges in piezoelectric energy harvesting and the studies focusing on these challenges are discussed. The conclusion part summarizes the current standing of piezoelectric energy harvesters as possible candidates for various applications and discusses the issues that need to be addressed for realization of practical piezoelectric energy harvesting devices.

Toprak, Alperen; Tigli, Onur

2014-09-01

223

A multiscale-based approach for composite materials with embedded PZT filaments for energy harvesting  

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

224

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

225

Energy-Harvesting Shock Absorber with a Mechanical Motion Zhongjie Li, Lei Zuo*, Jian Kuang, and George Luhrs  

E-print Network

is able to recover the energy otherwise dissipated in the suspension vibration while simultaneously energy harvesting such as from tall buildings or long bridges. 1. Introduction The transportation counts suspensions have substantial influence on the fuel efficiency [4]. Through modeling and road tests, Zuo

Zuo, Lei

226

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

NASA Astrophysics Data System (ADS)

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

Anton, Steven R.; Inman, Daniel J.

2011-03-01

227

Cloudy Computing: Leveraging Weather Forecasts in Energy Harvesting Sensor Systems  

E-print Network

Cloudy Computing: Leveraging Weather Forecasts in Energy Harvesting Sensor Systems Navin Sharma,gummeson,irwin,shenoy}@cs.umass.edu Abstract--To sustain perpetual operation, systems that harvest environmental energy must carefully regulate their usage to satisfy their demand. Regulating energy usage is challenging if a system's demands

Shenoy, Prashant

228

Finite-Horizon Optimal Transmission Policies for Energy Harvesting Sensors  

E-print Network

Finite-Horizon Optimal Transmission Policies for Energy Harvesting Sensors Rahul Vaze School: krishnaj@ee.iitm.ac.in Abstract--In this paper, we derive optimal transmission poli- cies for energy harvesting sensors to maximize the utility obtained over a finite horizon. First, we consider a single energy

Jagannathan, Krishna

229

Energy Harvesting for Self-Powered Nanosystems Zhong Lin Wang  

E-print Network

Energy Harvesting for Self-Powered Nanosystems Zhong Lin Wang School of Materials Science In this article, an introduction is presented about the energy harvesting technologies that have potential. This is a potential technology for converting mechanical movement energy (such as body movement, muscle stretching

Wang, Zhong L.

230

Improving Energy Efficiency for Energy Harvesting Embedded Systems*  

E-print Network

effective approach with high power conversion efficiency and low self-discharge. In this paper, we propose efficiency improvement and run- time overhead reduction compared to previous approaches. Keywords HybridImproving Energy Efficiency for Energy Harvesting Embedded Systems* Yang Ge, Yukan Zhang and Qinru

Qiu, Qinru

231

Ecological impacts of energy-wood harvests: lessons from whole-tree harvesting and natural disturbance  

USGS Publications Warehouse

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

232

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

Microsoft Academic Search

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

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

2003-01-01

233

Energy transfer of highly vibrationally excited naphthalene. II. Vibrational energy dependence and isotope and mass effects  

Microsoft Academic Search

The vibrational energy dependence, H and D atom isotope effects, and the mass effects in the energy transfer between rare gas atoms and highly vibrationally excited naphthalene in the triplet state were investigated using crossed-beam\\/time-sliced velocity-map ion imaging at various translational collision energies. Increase of vibrational energy from 16 194 to 18 922 cm?1 does not make a significant difference

Chen-Lin Liu; Hsu Chen Hsu; Yuan Chin Hsu; Chi-Kung Ni

2008-01-01

234

Energy transfer of highly vibrationally excited naphthalene. II. Vibrational energy dependence and isotope and mass effects  

Microsoft Academic Search

The vibrational energy dependence, H and D atom isotope effects, and the mass effects in the energy transfer between rare gas atoms and highly vibrationally excited naphthalene in the triplet state were investigated using crossed-beam\\/time-sliced velocity-map ion imaging at various translational collision energies. Increase of vibrational energy from 16 194 to 18 922 cm-1 does not make a significant difference

Chen-Lin Liu; Hsu Chen Hsu; Yuan Chin Hsu; Chi-Kung Ni

2008-01-01

235

MEMS based pyroelectric thermal energy harvester  

DOEpatents

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

Hunter, Scott R; Datskos, Panagiotis G

2013-08-27

236

Design considerations for solar energy harvesting wireless embedded systems  

Microsoft Academic Search

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

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

2005-01-01

237

Delay Optimal Scheduling for Energy Harvesting Based Communications  

E-print Network

for a bursty wireless link that is powered by a capacity-limited battery storing the harvested energy, in particular sensor networks powered by capacity limited batteries, can be substantially extended. Energy harvesting can also help reduce carbon emission and environmental pollution, as well as reliance

Dai, Huaiyu

238

Resource management for fading wireless channels with energy harvesting nodes  

Microsoft Academic Search

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

239

The Internet of Tags: Energy-Harvesting Adaptive Algorithms  

E-print Network

(IoTags). We believe that IoTags will be a key component of the Internet of Things (IoT). In the nearThe Internet of Tags: Energy-Harvesting Adaptive Algorithms Robert Margolies Ph.D. Candidate a top-down approach and develop energy harvesting adaptive algorithms to support the Internet of Tags

Hone, James

240

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

241

Analytical model for nonlinear piezoelectric energy harvesting devices  

NASA Astrophysics Data System (ADS)

In this work we propose analytical expressions for the jump-up and jump-down point of a nonlinear piezoelectric energy harvester. In addition, analytical expressions for the maximum power output at optimal resistive load and the 3 dB-bandwidth are derived. So far, only numerical models have been used to describe the physics of a piezoelectric energy harvester. However, this approach is not suitable to quickly evaluate different geometrical designs or piezoelectric materials in the harvester design process. In addition, the analytical expressions could be used to predict the jump-frequencies of a harvester during operation. In combination with a tuning mechanism, this would allow the design of an efficient control algorithm to ensure that the harvester is always working on the oscillatorʼs high energy attractor.

Neiss, S.; Goldschmidtboeing, F.; Kroener, M.; Woias, P.

2014-10-01

242

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

NASA Astrophysics Data System (ADS)

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

Cassidy, Ian L.

243

A micro energy harvester with 3D wire bonded microcoils  

Microsoft Academic Search

We developed the first micro energy harvester with optimized wire bonded microcoils. The coils were fabricated with a fully automated process on PCB. The 3D coils enable to effectively use the magnetic field and generate an output power of 0.62 !W at 1 ms -2 within a total harvester volume of 0.46 cm 3 . With the coil wire thickness

C. Cepnik; U. Wallrabe

2011-01-01

244

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 µW. 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

245

Development of an energy harvesting backpack and performance evaluation.  

PubMed

A biomechanical energy harvesting backpack that generates electrical energy during human walking is presented. This device differs from previous designs because it integrates motion from both lower limbs into a single mechanical drive train. The energy harvesting backpack produced an average of 15 W of electricity during walking at a speed of 1.2m/s. It was found that approximately one quarter of the total mechanical work harvested was from the negative work performed during walking. This technology could potentially be used to power portable biomedical devices. PMID:24187228

Shepertycky, Michael; Zhang, Jun-Tian; Liu, Yan-Fei; Li, Qingguo

2013-06-01

246

Energy harvesting based on piezoelectric Ericsson cycles in a piezoceramic material  

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

247

Scaling of electromagnetic transducers for shunt damping and energy harvesting  

NASA Astrophysics Data System (ADS)

In order for an electromagnetic transducer to operate well as either a mechanical shunt damper or as a vibration energy harvester, it must have good electromechanical coupling. A simple two-port analysis is used to derive a non-dimensional measure of electromechanical coupling, which must be large compared with unity for efficient operation in both of these applications. The two-port parameters for an inertial electromagnetic transducer are derived, from which this non-dimensional coupling parameter can be evaluated. The largest value that this parameter takes is approximately equal to the square of the magnetic flux density times the length of wire in the field, divided by the mechanical damping times the electrical resistance. This parameter is found to be only of the order of one for voice coil devices that weigh approximately 1 kg, and so such devices are generally not efficient, within the definition used here, in either of these applications. The non-dimensional coupling parameter is found to scale in approximate proportion to the device's characteristic length, however, and so although miniaturised devices are less efficient, greater efficiency can be obtained with large devices, such as those used to control civil engineering structures.

Elliott, Stephen J.; Zilletti, Michele

2014-04-01

248

Innovative thermal energy harvesting for future autonomous applications  

NASA Astrophysics Data System (ADS)

As communicating autonomous systems market is booming, the role of energy harvesting will be a key enabler. As example, heat is one of the most abundant energy sources that can be converted into electricity in order to power circuits. Harvesting systems that use wasted heat open new ways to power autonomous sensors when the energy consumption is low, or to create systems of power generators when the conversion efficiency is high. The combination of different technologies (low power ?-processors, ?-batteries, radio, sensors...) with new energy harvesters compatible with large varieties of use-cases with allow to address this booming market. Thanks to the conjunction of ultra-low power electronic development, 3D technologies & Systems in Package approaches, the integration of autonomous sensors and electronics with ambient energy harvesting will be achievable. The applications are very wide, from environment and industrial sensors to medical portable applications, and the Internet of things may also represent in the future a several billions units market.

Monfray, Stephane

2013-12-01

249

Modeling and nonlinear analysis of piezoelectric energy harvesting from transverse galloping  

NASA Astrophysics Data System (ADS)

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

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

2013-02-01

250

Evaluation of flexible transducers for motion energy harvesting  

NASA Astrophysics Data System (ADS)

Personal electronic devices such as mobile/cell phones, radios and wireless sensors traditionally depend on energy storage technologies, such as batteries, for operation. By harvesting energy from the local environment, these devices can achieve greater run-times without the need for battery recharging or replacement. Harvesting energy could also achieve a reduction in the weight and volume of the personal devices - as batteries often make up more than half the weight/volume of these devices. Motion energy harvesting is one such approach where energy from mechanical motion can be converted into electrical energy. This can be achieved through the use of flexible piezoelectric transducer materials such as polyvinylidene fluoride (PVDF). A problem with these transducer materials it that their behaviour is non-linear due to operating and environmental conditions. Hence, for this reason researchers have found it has been difficult to measure the harvesting performance i.e. mechanical-to-electrical conversion efficiency. At CSIRO we are currently evaluating the performance of flexible transducers for use as motion energy harvesters. Preliminary results suggest an overall energy harvesting conversion efficiency of 0.65% for a flexible transducer material.

Collins, Michael; Behrens, Sam; McGarry, Scott

2009-03-01

251

Dynamic Power Allocation For Maximizing Throughput in Energy Harvesting  

E-print Network

1 Dynamic Power Allocation For Maximizing Throughput in Energy Harvesting Communication System general case of arbitrarily varying energy arrivals is considered, where neither the future energy arrival strategy that invests available energy uniformly over all remaining slots until the next energy arrival

Vaze, Rahul

252

Design and Power Management of Energy Harvesting Embedded Systems  

E-print Network

sources that will scale well with economy. Energy harvesting itself is not new, but what is new is how their constraints. For instance, windmills and hydroelectric generators have been in use for a long time, and solar

Chou, Pai H.

253

Energy Harvesting for Self-Powered Wireless Sensors  

E-print Network

memory alloy (MSMA) energy harvesting material and a low-frequency, low-power rectifier multiplier (RM). Experimental characterizations of the MSMA device and the RM are presented. A study on practical implementation of a strain gauge sensor and its...

Wardlaw, Jason

2012-02-14

254

Fundamental study of mechanical energy harvesting using piezoelectric nanostructures  

E-print Network

demonstrated by using piezo- electric ZnO nanowires NWs to harvest micro- and nano- scale mechanical energy- bots, NEMS/MEMS, and bioimplantable devices.12,17,18 Successful prototypes have been developed using

Wang, Xudong

255

Design of test bench apparatus for piezoelectric energy harvesters  

E-print Network

This thesis presents the design and analysis of an experimental test bench for the characterization of piezoelectric microelectromechanical system (MEMS) energy harvester being developed by the Micro & Nano Systems Laboratory ...

Yoon, You C. (You Chang)

2013-01-01

256

Laminate composites with enhanced pyroelectric effects for energy harvesting  

Microsoft Academic Search

A pyroelectric coefficient enhanced 2-2 connectivity laminate composites' energy harvesting credentials have been assessed. The use of the electrothermal coupling factor for laminate composites (kLam2) for such an assessment has been appraised while the experimental samples are evaluated to show a significant improvement in their performance via pyroelectric coefficient enhancement, demonstrative of their great potential in energy harvesting applications. A

H. H. S. Chang; Z. Huang

2010-01-01

257

Hybrid Nanogenerator for Concurrently Harvesting Biomechanical and Biochemical Energy  

Microsoft Academic Search

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 potentialin vivoapplications. The hybrid device consists of a piezoelectric poly(vinylidenefluoride) nanofiber nanogeneratorforharvestingmechanicalenergy,suchasfrombreathingorfromthebeatofaheart,andaflexible enzymatic biofuel cell for harvesting the

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

2010-01-01

258

Infrared Energy Harvesting for Optoplasmonics from Nanostructured Metamaterials  

NASA Astrophysics Data System (ADS)

Metamaterials exhibit unique optical resonance characteristics which permit precise engineering of energy pathways within a device. The ability of plasmonic nanostructures to guide electromagnetism offers a platform to reduce global dependence on fossil fuels by harvesting waste heat, which comprises 60% of generated energy around the world. Plasmonic metamaterials were hypothesized to support an exchange of energy between resonance modes, enabling generation of higher energy photons from waste infrared energy. Infrared irradiation of a metamaterial at the Fano coupling lattice resonance was anticipated to re-emit as higher energy visible light at the plasmon resonance. Photonic signals from harvested thermal energy could be used to power wearable medical monitors or off-grid excursions, for example. This thesis developed the design, fabrication, and characterization methods to realize nanostructured metamaterials which permit resonance exchange for infrared energy harvesting applications.

Forcherio, Gregory Thomas

259

Efficient energy transfer in light-harvesting systems, I: optimal temperature, reorganization energy, and spatial-  

E-print Network

Efficient energy transfer in light-harvesting systems, I: optimal temperature, reorganization of efficient and robust energy transfer in light-harvesting systems provides new insights for the optimal dynamics in light harvesting systems and energy transfer efficiency 2. Optimization in the Haken

Cao, Jianshu

260

A bulk micromachined lead zinconate titanate cantilever energy harvester with inter-digital IrO(x) electrodes.  

PubMed

A piezoelectric vibration energy harvester with inter-digital IrO(x) electrode was developed by using silicon bulk micromachining technology. Most PZT cantilever based energy harvesters have utilized platinum electrode material. However, the PZT fatigue characteristics and adhesion/delamination problems caused by the platinum electrode might be serious problem in reliability of energy harvester. To address these problems, the iridium oxide was newly applied. The proposed energy harvester was comprised of bulk micromachined silicon cantilever with 800 x 1000 x 20 microm3, which having a silicon supporting membrane, sol-gel-spin coated Pb(Zr52, Ti48)O3 thin film, and sputtered inter-digitally shaped IrO(x) electrodes, and silicon inertial mass with 1000 x 1000 x 500 microm3 to adjust its resonant frequency. The fabricated energy harvester generated 1 microW of electrical power to 470 komega of load resistance and 1.4 V(peak-to-peak) from a vibration of 0.4 g at 1.475 kHz. The corresponding power density was 6.25 mW x cm(-3) x g(-2). As expected, its electrical failure was significantly improved. PMID:24245226

Park, Jongcheol; Park, Jae Yeong

2013-10-01

261

A Shoe-Embedded Piezoelectric Energy Harvester for Wearable Sensors  

PubMed Central

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

262

Development of MEMS based pyroelectric thermal energy harvesters  

SciTech Connect

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

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

2011-01-01

263

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

264

Thermoelectric Energy Harvesting from Transient Ambient Temperature Gradients  

NASA Astrophysics Data System (ADS)

We examine a thermoelectric harvester that converts electrical energy from the naturally occurring temperature difference between ambient air and large thermal storage capacitors such as building walls or the soil. For maximum power output, the harvester design is implemented in two steps: source matching of the thermal and electrical interfaces to the energy source (system level) followed by load matching of the generator to these interfaces (subsystem level). Therefore, we measure thermal source properties such as the temperature difference, the air velocity, and the cutoff frequency in two application scenarios (road tunnel and office building). We extend a stationary model of the harvester into the time domain to account for transient behavior of the source. Based on the model and the source measurements, we perform the source and load matching. The resulting harvester consists of a pin fin heat sink with a thermal resistance of 6.2 K/W and a cutoff frequency 2.5 times greater than that of the source, a thermoelectric generator, and a DC/DC step-up converter starting at a total temperature difference of only ? T = 1.2 K. In a final road tunnel field test, this optimized harvester converts 70 mJ of electrical energy per day without any direct solar irradiation. The energy provided by the harvester enables 415 data transmissions from a wireless sensor node per day.

Moser, André; Erd, Metin; Kostic, Milos; Cobry, Keith; Kroener, Michael; Woias, Peter

2012-06-01

265

Single stage AC-DC converter for Galfenol-based micro-power energy harvesters  

NASA Astrophysics Data System (ADS)

Military based sensor systems are often hindered in operational deployment and/or other capabilities due to limitations in their energy storage elements. Typically operating from lithium based batteries, there is a finite amount of stored energy which the sensor can use to collect and transmit data. As a result, the sensors have reduced sensing and transmission rates. However, coupled with the latest advancements in energy harvesting, these sensors could potentially operate at standard sensing and transition rates as well as dramatically extend lifetimes. Working with the magnetostrictive material Galfenol, we demonstrate the production of enough energy to supplement and recharge a solid state battery thereby overcoming the deficiencies faced by unattended sensors. As with any vibration-based energy harvester, this solution produces an alternating current which needs to be rectified and boosted to a level conducive to recharge the storage element. This paper presents a power converter capable of efficiently converting an ultra-low AC voltage to a solid state charging voltage of 4.1VDC. While we are working with Galfenol transducers as our energy source, this converter may also be applied with any AC producing energy harvester, particularly at operating levels less than 2mW and 200mVAC.

Cavaroc, Peyton; Curtis, Chandra; Naik, Suketu; Cooper, James

2014-06-01

266

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

PubMed Central

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

Yang, Yoonseok; Yeo, Jeongjin; Priya, Shashank

2012-01-01

267

Custom IC for Ultra-low Power RF Energy Harvesting  

Microsoft Academic Search

This paper presents a custom IC that provides an efficient interface between an ultra-low power RF rectifying antenna (rectenna) source and a microbattery, with the goal of maximum power harvesting. The energy harvester IC uses current-starved circuitry, a non-overlapping gate-drive, and a sub-threshold current source to achieve a nominal supply current in the 200 nA range for VDD = 2.5

Thurein Paing; Erez Falkenstein; Regan Zane; Zoya Popovic

2009-01-01

268

PIEZOELECTRIC POWER SCAVENGING OF MECHANICAL VIBRATION ENERGY  

E-print Network

PIEZOELECTRIC POWER SCAVENGING OF MECHANICAL VIBRATION ENERGY PIEZOELECTRIC POWER SCAVENGING and magneticand magnetic field.field. Piezoelectric Materials as Smart Material- Among the all smart materials, piezoelectric materials are of great interest, as they are commonly used as sensors, actuators and memory

Ervin, Elizabeth K.

269

Harvesting Energy from Wastewater in a 2-Chamber  

E-print Network

Harvesting Energy from Wastewater in a 2-Chamber Microbial Fuel Cell Sikandar Present day wastewater treatment plants utilize high amounts of energy and are costly to operate. These conventional wastewater treatment plants utilize aerobic bacteria. Organic material in wastewater contains energy that can

270

Harvesting Chaparral Biomass for Energy--An Environmental Assessment1  

E-print Network

Harvesting Chaparral Biomass for Energy--An Environmental Assessment1 Philip J. Riggan and Paul H and could provide a locally important alternative source of energy. CHAPARRAL BIOMASS Considerable amounts of potential energy are present in the biomass of some chaparral communi- ties. Biomass in mature Adenostoma

Standiford, Richard B.

271

A millimeter-sized electret-energy-harvester with microfabricated horizontal arrays and vertical protrusions for power generation enhancement  

Microsoft Academic Search

This paper describes a millimeter-sized electret vibrational energy harvester fabricated by a MEMS-based process for power generation enhancement. To increase current generation, we developed a new “slit-and-slider” structure with horizontal arrays and vertical protrusions. This structure enables us to increase an area and to narrow a gap of energy conversion in the limited size. The structure was fabricated by gold-electroplating.

K. Ono; N. Sato; T. Shimamura; M. Ugajin; T. Sakata; S. Mutoh; Y. Sato

2011-01-01

272

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

2012-04-01

273

Hybridizing triboelectrification and electromagnetic induction effects for high-efficient mechanical energy harvesting.  

PubMed

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

274

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

275

Energy Aware Dynamic Voltage and Frequency Selection for Real-Time Systems with Energy Harvesting  

E-print Network

Energy Aware Dynamic Voltage and Frequency Selection for Real-Time Systems with Energy Harvesting}@binghamton.edu Abstract In this paper, an energy aware dynamic voltage and frequency selection (EA-DVFS) algorithm energy and the harvested energy in a future duration. Specifically, if the system has sufficient energy

Qiu, Qinru

276

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

PubMed

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

Radousky, H B; Liang, H

2012-12-21

277

Vibration-to-electric energy conversion  

Microsoft Academic Search

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

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

1999-01-01

278

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

2010-04-01

279

Design and experimental evaluation on an advanced multisource energy harvesting system for wireless sensor nodes.  

PubMed

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

280

Studying piezoelectric nanowires and nanowalls for energy harvesting  

Microsoft Academic Search

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

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

2009-01-01

281

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

282

Energy harvesting using a PZT ceramic multilayer stack  

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

283

Practical implementation of piezoelectric energy harvesting synchronized switching schemes  

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

284

Harvesting renewable energy from Earth's mid-infrared emissions  

PubMed Central

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

2014-01-01

285

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

PubMed

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

286

Converged vibrational energy levels and quantum mechanical vibrational partition function of ethane  

E-print Network

Converged vibrational energy levels and quantum mechanical vibrational partition function of ethane a combined valence-bond mo- lecular mechanics CVBMM potential energy surface.26 The calculations are carried function of ethane is calculated in the temperature range of 200­600 K using well-converged energy levels

Truhlar, Donald G

287

An Optimal Energy Allocation Algorithm for Energy Harvesting Wireless Sensor Networks  

E-print Network

by enabling the wireless sensor nodes to replenish energy from ambient sources, such as solar, wind expenditure may limit the throughput by failing to take the full advantage of the energy harvesting processAn Optimal Energy Allocation Algorithm for Energy Harvesting Wireless Sensor Networks Shaobo Mao

Wong, Vincent

288

Organoruthenium Complexes for Solar Energy Harvesting  

Microsoft Academic Search

One of the greatest challenges of this time is providing the world with the energy it needs to sustain human kind's current standard of living. Solar energy is the most abundant and ubiquitous renewable energy source available, and as such it holds great promises. Traditionally, the field of solar energy conversion has been dominated by solid-state semiconductor technology. However, the

S. H. Wadman

2008-01-01

289

Piezoelectric touch-sensitive flexible hybrid energy harvesting nanoarchitectures  

NASA Astrophysics Data System (ADS)

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.

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

2010-10-01

290

Energy harvesting from electric power lines employing the Halbach arrays  

NASA Astrophysics Data System (ADS)

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.

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

2013-10-01

291

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

292

Harvesting Energy from the Marine Sediment-Water Interface  

E-print Network

Harvesting Energy from the Marine Sediment-Water Interface C L A R E E . R E I M E R S * College the net oxidation of sediment organic matter by dissolved seawater oxygen. Considering typical sediment in the coastal ocean. Introduction Microbial decomposition of marine sediment organic matter consumes

Rosen, I. Gary

293

A shoe-equipped linear generator for energy harvesting  

Microsoft Academic Search

This paper presents a linear generator used for energy harvesting system equipped in footwear, which scavenges power from back-and-forth motion during walk. Structure of the electric machine is studied, and sizing optimization by finite element analysis (FEA) is detailed. A prototype has been built, validating that the simulated and test results have a good agreement.

Can-Fei Wang; Dong-Min Miao; Patrick Chi-Kwong Luk; Jian-Xin Shen; Chi Xu; Dan Shi

2010-01-01

294

Acoustic energy harvesting using resonant cavity of a sonic crystal  

Microsoft Academic Search

This paper presents the development of an acoustic energy harvester using the sonic crystal and the piezoelectric material. A point defect is created by removing a rod from a perfect sonic crystal. The point defect in the sonic crystal acts as a resonant cavity, and the acoustic waves at the resonant frequency of the cavity can be localized in the

Liang-Yu Wu; Lien-Wen Chen; Chia-Ming Liu

2009-01-01

295

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

296

Metamaterials-based enhanced energy harvesting: A review  

NASA Astrophysics Data System (ADS)

Advances in low power design open the possibility to harvest ambient energies to power directly the electronics or recharge a secondary battery. The key parameter of an energy harvesting (EH) device is its efficiency, which strongly depends on the conversion medium. To address this issue, metamaterials, artificial materials and structures with exotic properties, have been introduced for EH in recent years. They possess unique properties not easily achieved using naturally occurring materials, such as negative stiffness, mass, Poisson's ratio, and refractive index. The goal of this paper is to review the fundamentals, recent progresses and future directions in the field of metamaterials-based enhanced energy harvesting. An introduction on EH followed by the classification of potential metamaterials for EH is presented. A number of theoretical and experimental studies on metamaterials-based EH are outlined, including phononic crystals, acoustic metamaterials, and electromagnetic metamaterials. Finally, we give an outlook on future directions of metamaterials-based energy harvesting research including but not limited to active metamaterials-based EH, metamaterials-based thermal EH, and metamaterials-based multifunctional EH capabilities.

Chen, Zhongsheng; Guo, Bin; Yang, Yongmin; Cheng, Congcong

2014-04-01

297

Light-harvesting materials: Soft support for energy conversion  

NASA Astrophysics Data System (ADS)

To convert solar energy into viable fuels, coupling light-harvesting materials to catalysts is a crucial challenge. Now, the combination of an organic supramolecular hydrogel and a non-precious metal catalyst has been demonstrated to be effective for photocatalytic H2 production.

Stolley, Ryan M.; Helm, Monte L.

2014-11-01

298

Energy harvesting for the implantable biomedical devices: issues and challenges.  

PubMed

The development of implanted devices is essential because of their direct effect on the lives and safety of humanity. This paper presents the current issues and challenges related to all methods used to harvest energy for implantable biomedical devices. The advantages, disadvantages, and future trends of each method are discussed. The concept of harvesting energy from environmental sources and human body motion for implantable devices has gained a new relevance. In this review, the harvesting kinetic, electromagnetic, thermal and infrared radiant energies are discussed. Current issues and challenges related to the typical applications of these methods for energy harvesting are illustrated. Suggestions and discussion of the progress of research on implantable devices are also provided. This review is expected to increase research efforts to develop the battery-less implantable devices with reduced over hole size, low power, high efficiency, high data rate, and improved reliability and feasibility. Based on current literature, we believe that the inductive coupling link is the suitable method to be used to power the battery-less devices. Therefore, in this study, the power efficiency of the inductive coupling method is validated by MATLAB based on suggested values. By further researching and improvements, in the future the implantable and portable medical devices are expected to be free of batteries. PMID:24950601

Hannan, Mahammad A; Mutashar, Saad; Samad, Salina A; Hussain, Aini

2014-01-01

299

Thermal energy harvesters with piezoelectric or electrostatic transducer  

NASA Astrophysics Data System (ADS)

This paper describes the idea of the energy harvester which converts thermal gradient present in environment into electricity. Two kinds of such devices are proposed and their prototypes are shown and discussed. The main parts of harvesters are bimetallic spring, piezoelectric transducer or electrostatic transducer with electret. The applied piezomembrane was commercial available product but electrets was made by authors. In the paper a fabrication procedure of electrets formed by the corona discharge process is described. Devices were compared in terms of generated power, charging current, and the voltage across a storage capacitor.

Prokaryn, Piotr; Doma?ski, Krzysztof; Marchewka, Micha?; Tomaszewski, Daniel; Grabiec, Piotr; Puscasu, Onoriu; Monfray, Stéphane; Skotnicki, Thomas

2014-08-01

300

Figure 1: Configuration of energy recovering system Modeling of an Electromechanical Energy Harvesting  

E-print Network

. Keywords--regenerative; energy harvesting; vehicle suspension; electromagnetic. I. INTRODUCTION Nowadays to roads irregularities and driving conditions such as acceleration, braking and curves. According

Paris-Sud XI, Université de

301

Energy harvesting measurements from stall flutter limit cycle oscillations  

NASA Astrophysics Data System (ADS)

Results from experiments using a two-degree-of-freedom airfoil system are presented. Air speeds of the airfoil are determined at which dynamic flutter can be initiated and where limit cycle oscillations (LCO) can be excited by initial (pitch or plunge) displacements. LCO's with large pitch angle displacements attributed to stall flutter behavior are measured. The LCO oscillations are converted into electric power by an electromagnetic-inductor device. The energy harvester consists of three magnets in which one magnet floats between two fixed magnets. The force-displacement relationship of the harvester is best described by a fifth-order polynomial. The integration of the harvester into the airfoil system introduces nonlinear stiffness into the vertical (plunge) direction. When the LCO has been initiated, displacement amplitudes and resulting power generation are measured.

Chen, Jasper; Dhanushkodi, Adit; Lee, Christopher L.

2014-04-01

302

Resonant vibrational energy transfer in ice Ih  

NASA Astrophysics Data System (ADS)

Fascinating anisotropy decay experiments have recently been performed on H2O ice Ih by Timmer and Bakker [R. L. A. Timmer, and H. J. Bakker, J. Phys. Chem. A 114, 4148 (2010)]. The very fast decay (on the order of 100 fs) is indicative of resonant energy transfer between OH stretches on different molecules. Isotope dilution experiments with deuterium show a dramatic dependence on the hydrogen mole fraction, which confirms the energy transfer picture. Timmer and Bakker have interpreted the experiments with a Förster incoherent hopping model, finding that energy transfer within the first solvation shell dominates the relaxation process. We have developed a microscopic theory of vibrational spectroscopy of water and ice, and herein we use this theory to calculate the anisotropy decay in ice as a function of hydrogen mole fraction. We obtain very good agreement with experiment. Interpretation of our results shows that four nearest-neighbor acceptors dominate the energy transfer, and that while the incoherent hopping picture is qualitatively correct, vibrational energy transport is partially coherent on the relevant timescale.

Shi, L.; Li, F.; Skinner, J. L.

2014-06-01

303

Flexible hybrid energy cell for simultaneously harvesting thermal, mechanical, and solar energies.  

PubMed

We report the first flexible hybrid energy cell that is capable of simultaneously or individually harvesting thermal, mechanical, and solar energies to power some electronic devices. For having both the pyroelectric and piezoelectric properties, a polarized poly(vinylidene fluoride) (PVDF) film-based nanogenerator (NG) was used to harvest thermal and mechanical energies. Using aligned ZnO nanowire arrays grown on the flexible polyester (PET) substrate, a ZnO-poly(3-hexylthiophene) (P3HT) heterojunction solar cell was designed for harvesting solar energy. By integrating the NGs and the solar cells, a hybrid energy cell was fabricated to simultaneously harvest three different types of energies. With the use of a Li-ion battery as the energy storage, the harvested energy can drive four red light-emitting diodes (LEDs). PMID:23199138

Yang, Ya; Zhang, Hulin; Zhu, Guang; Lee, Sangmin; Lin, Zong-Hong; Wang, Zhong Lin

2013-01-22

304

Harvesting the Sun's Energy with Antennas  

ScienceCinema

Researchers at Idaho National Laboratory, along with partners at Microcontinuum Inc. (Cambridge, MA) and Patrick Pinhero of the University of Missouri, are developing a novel way to collect energy from the sun with a technology that could potentially cost pennies a yard, be imprinted on flexible materials and still draw energy after the sun has set.

INL

2009-09-01

305

Nonlinear beam-based vibration energy harvesters and load cells  

E-print Network

This thesis studies a novel nonlinear spring mechanism that is comprised of a cantilever wrapping around a curved surface as it deflects. Static force versus displacement tests and dynamic "initial displacement" tests ...

Kluger, Jocelyn Maxine

2014-01-01

306

Energy harvesting with piezoelectric circular membrane under pressure loading  

NASA Astrophysics Data System (ADS)

This paper presents a comprehensive theoretical model for predicting the energy generating performance of an energy harvesting device that uses a piezoelectric circular membrane subject to pressure fluctuation. PVDF (polyvinylidene fluoride) film is adopted for the membrane. In order to predict the power generating performance due to stretching and bending of the membrane, the total stress on the membrane, rather than the stress at the center point of the circular membrane, is determined using the energy method. Analytical results indicate that the theoretically predicted generated power of the device under normal blood pressure variation is close to experimental results available in the literature. This comprehensive model provides a useful design tool during parameter optimization for energy harvesters that use piezoelectric circular membranes for a pressure fluctuating system.

Mo, Changki; Davidson, Joseph; Clark, William W.

2014-04-01

307

Perspectives on Energy-Harvesting Wireless Sensor Networks  

Microsoft Academic Search

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

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

308

Green energy harvesting technology in 3D IC  

Microsoft Academic Search

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

Wei Wang; Weng Hong Teh

2010-01-01

309

Comparison of energy harvesting systems for wireless sensor networks  

Microsoft Academic Search

Wireless sensor networks (WSNs) offer an attractive solution to many environmental, security, and process monitoring problems.\\u000a However, one barrier to their fuller adoption is the need to supply electrical power over extended periods of time without\\u000a the need for dedicated wiring. Energy harvesting provides a potential solution to this problem in many applications. This\\u000a paper reviews the characteristics and energy

James M. Gilbert; Farooq Balouchi

2008-01-01

310

Dynamic Reconfiguration of Photovoltaic Energy Harvesting System in Hybrid Electric Vehicles  

E-print Network

Dynamic Reconfiguration of Photovoltaic Energy Harvesting System in Hybrid Electric Vehicles Yanzhi, xuelin, pedram}@usc.edu, 2 {naehyuck}@elpl.snu.ac.kr ABSTRACT Photovoltaic (PV) energy harvesting system. Keywords Photovoltaic System, Hybrid Electric Vehicle, Photovoltaic Array Reconfiguration, Dynamic

Pedram, Massoud

311

7/30/2014 Smart sensors that harvest power from sun, heat or vibrations https://ec.europa.eu/programmes/horizon2020/en/print/688 1/2  

E-print Network

2020/en/print/688 1/2 Date: 18/02/2014 - 19:37 Published on Horizon 2020 (https://ec.europa.eu/programmes/horizon7/30/2014 Smart sensors that harvest power from sun, heat or vibrations https://ec.europa.eu/programmes/horizon2020) Smart sensors that harvest power from sun, heat or vibrations Published by newsroom editor

Rossi, Michele

312

Production, Delivery and Application of Vibration Energy in Healthcare  

NASA Astrophysics Data System (ADS)

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

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

2011-02-01

313

Structures, systems and methods for harvesting energy from electromagnetic radiation  

DOEpatents

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

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

2011-12-06

314

Piezoelectric polymer multilayer on flexible substrate for energy harvesting.  

PubMed

A piezoelectric polymer multilayer structure formed on a flexible substrate is investigated for mechanical energy harvesting under bending mode. Analytical and numerical models are developed to clarify the effect of material parameters critical to the energy harvesting performance of the bending multilayer structure. It is shown that the maximum power is proportional to the square of the piezoelectric stress coefficient and the inverse of dielectric permittivity of the piezoelectric polymer. It is further found that a piezoelectric multilayer with thinner electrodes can generate more electric energy in bending mode. The effect of improved impedance matching in the multilayer polymer on energy output is remarkable. Comparisons between piezoelectric ceramic multilayers and polymer multilayers on flexible substrate are discussed. The fabrication of a P(VDF-TrFE) multilayer structure with a thin Al electrode layer is experimentally demonstrated by a scalable dip-coating process on a flexible aluminum substrate. The results indicate that it is feasible to produce a piezoelectric polymer multilayer structure on flexible substrate for harvesting mechanical energy applicable for many low-power electronics. PMID:24658732

Zhang, Lei; Oh, Sharon Roslyn; Wong, Ting Chong; Tan, Chin Yaw; Yao, Kui

2013-09-01

315

Feasibility of Energy Harvesting Using a Piezoelectric Tire  

NASA Astrophysics Data System (ADS)

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

Malotte, Christopher

316

Delay-Tolerant Data Gathering in Energy Harvesting Sensor Networks With a Mobile Sink  

E-print Network

Delay-Tolerant Data Gathering in Energy Harvesting Sensor Networks With a Mobile Sink Xiaojiang Ren collection in an energy harvesting sensor network with a mobile sink, where a mobile sink travels along, this is the first kind of work of data collection for energy harvesting sensor networks with mobile sinks. I

Liang, Weifa

317

An electroactive polymer energy harvester for wireless sensor networks  

NASA Astrophysics Data System (ADS)

This paper reports the design, fabrication, and testing of a soft electroactive polymer power generator that has a volume of 1cm3. The generator provides an opportunity to harvest energy from environmental sources to power wireless sensor networks because it can harvest from low frequency motions, is compact, and lightweight. Electroactive polymers are highly stretchable variable capacitors. Electrical energy is produced when the deformation of a stretched, charged electroactive polymer is relaxed; like-charges are compressed together and opposite-charges are pushed apart, resulting in an increased voltage. Although electroactive polymers have impressively displayed energy densities as high as 550 mJ/g, they have been based on films with thicknesses of tens to hundreds of micrometers, thus a generator covering a large area would be required to provide useful power. Energy harvesters covering large areas are inconvenient to deploy in a wireless sensor network with a large number of nodes, so a generator that is compact in all three dimensions is required. In this work we fabricated a generator that can fit within a 11×11×9 mm envelope by stacking 42, 11mm diameter generator films on top of each other. When compressed cyclically at a rate of 0.5 Hz our generator produced 300 uW of power which is a sufficient amount of power for a low power wireless sensor node. The combination of our generator's small form factor and ability to harvest useful energy from low frequency motions provides an opportunity to deploy large numbers of wireless sensor nodes without the need for periodic, costly battery replacement.

McKay, T. G.; Rosset, S.; Anderson, I. A.; Shea, H.

2013-12-01

318

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

NASA Astrophysics Data System (ADS)

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

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

2012-07-01

319

Comparison between piezoelectric and magnetic strategies for wearable energy harvesting  

NASA Astrophysics Data System (ADS)

This paper introduces the design and fabrication of energy harvesters for the power generation from human body motion. Two alternative strategies are compared: piezoelectric and magnetic inductive. The generated energy is used to supply body sensors including accelerometers and temperature sensors and RF module. Two prototypes of the magnetic based generator and of the piezoelectric generator are built and tested with shaker at resonance condition and by dedicated bench reproducing joints rotation during walking. The experimental results show that the magnetic prototype can generate 0.7mW from human body motion, while the piezo harvester generates 0.22 and 0.33?W respectively for flexion and extension at angular velocity lower than 1rad/s and 45° amplitude.

De Pasquale, G.; Somà, A.; Fraccarollo, F.

2013-12-01

320

IPMC as a mechanoelectric energy harvester: tailored properties  

NASA Astrophysics Data System (ADS)

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

Tiwari, R.; Kim, K. J.

2013-01-01

321

Energy harvesting from a backpack instrumented with piezoelectric shoulder straps  

NASA Astrophysics Data System (ADS)

Over the past few decades the use of portable and wearable electronics has grown steadily. These devices are becoming increasingly more powerful. However, the gains that have been made in the device performance have resulted in the need for significantly higher power to operate the electronics. This issue has been further complicated due to the stagnant growth of battery technology over the past decade. In order to increase the life of these electronics, researchers have begun investigating methods of generating energy from ambient sources such that the life of the electronics can be prolonged. Recent developments in the field have led to the design of a number of mechanisms that can be used to generate electrical energy, from a variety of sources including thermal, solar, strain, inertia, etc. Many of these energy sources are available for use with humans, but their use must be carefully considered such that parasitic effects that could disrupt the user's gait or endurance are avoided. These issues have arisen from previous attempts to integrate power harvesting mechanisms into a shoe such that the energy released during a heal strike could be harvested. This study develops a novel energy harvesting backpack that can generate electrical energy from the differential forces between the wearer and the pack. The goal of this system is to make the energy harvesting device transparent to the wearer such that his or her endurance and dexterity is not compromised. This will be accomplished by replacing the traditional strap of the backpack with one made of the piezoelectric polymer polyvinylidene fluoride (PVDF). Piezoelectric materials have a structure such that an applied electrical potential results in a mechanical strain. Conversely, an applied stress results in the generation of an electrical charge, which makes the material useful for power harvesting applications. PVDF is highly flexible and has a high strength, allowing it to effectively act as the load bearing member. In order to preserve the performance of the backpack and user, the design of the pack will be held as close to existing systems as possible. This paper develops a theoretical model of the piezoelectric strap and uses experimental testing to identify its performance in this application.

Granstrom, Jonathan; Feenstra, Joel; Sodano, Henry A.; Farinholt, Kevin

2007-10-01

322

Suspended electrodes for reducing parasitic capacitance in electret energy harvesters  

NASA Astrophysics Data System (ADS)

MEMS electret energy harvesting devices are believed promising to replace coin batteries in low-power consumption electronics such as wireless sensor nodes and wearable devices. However, the parasitic capacitance of the interdigital electrodes imposes significant restrictions to enhancing the power output. To address this issue, this paper presents a novel low-k electrode structure based on a new model of the parasitic capacitance in electret energy harvesters. By employing the trench-filled parylene technology, metal electrodes suspended with deep honeycomb parylene structures have been prototyped. Thanks to the high air volume fraction (76%) of the honeycomb parylene structure, the effective relative permittivity ?eff surrounding the electrodes is reduced to as low as 1.8 when the air gap is 90 µm between the electret surface and the counter electrode. As a result, the parasitic capacitance in the electret energy harvester is decreased by 36% compared with that of electrodes on glass substrates, which leads to a 35% increase in the power output.

Chen, Rui; Suzuki, Yuji

2013-12-01

323

Human Motion Energy Harvester for Biometric Data Monitoring  

NASA Astrophysics Data System (ADS)

In this paper we present an energy autonomous sensor system fully integrated into the heel of a shoe for biometric data monitoring. For powering the wireless sensor system a pulse-driven energy harvester was developed, which uses the acceleration-impulses from heel-strike during walking. In preparation of the device development acceleration measurements were carried out. The pulse-driven energy harvester is based on the electromagnetic conversion principle and incorporates a 4×4 coil matrix. A beam fixed at both ends is used for suspending the magnetic circuit. The geometric parameters of coil and magnetic circuit were optimized for maximum power output. For an idealized acceleration pulse with a width of 5 ms and a height of 200 m/s2 an average power output of 0.7 mW was generated using a step frequency of 1 Hz. The functionality of the self-sustained sensor system is demonstrated by measuring the temperature and step-frequency of a walking person and transmitting the data to a base station. We also found that the implementation of the suspension can have a significant impact on the harvester performance reducing the power output.

Hoffmann, D.; Folkmer, B.; Manoli, Y.

2013-12-01

324

Power performance improvements for high pressure ripple energy harvesting  

NASA Astrophysics Data System (ADS)

A hydraulic pressure energy harvester (HPEH) device, which utilizes a housing in order to isolate a piezoelectric stack from the hydraulic fluid via a mechanical interface, generates power by converting the dynamic pressure within the system into electricity. Energy harvester prototypes were designed for generating low-power electricity from pressure ripples. These devices generate low-power electricity from off-resonance dynamic pressure excitation. The power produced per volume of piezoelectric material is analyzed to increase the power density; this is accomplished through evaluating piezoelectric stack characteristics, adding an inductor to the system circuit, and solving for optimal loading in order to achieve maximum power output. The prototype device utilizes a piezoelectric stack with high overall capacitance, which allows for inductance matching without using an active circuit. This work presents an electromechanical model and the experimental results of the HPEH devices using a parallel connection of inductive and resistive loads as the energy harvesting circuit. A non-ideal inductive load case is also considered and successfully modeled by accounting for the parasitic resistance of the inductive load. Various HPEH prototypes are fabricated, modeled, and compared in terms of their normalized power density levels, and milli-Watt level average power generation is demonstrated. The highest power density is reported for the single-crystal HPEH prototype.

Skow, E. A.; Cunefare, K. A.; Erturk, A.

2014-10-01

325

Energy harvesting under combined aerodynamic and base excitations  

NASA Astrophysics Data System (ADS)

This paper investigates the transduction of a piezoaeroelastic energy harvester under the combination of vibratory base excitations and aerodynamic loadings. The harvester which consists of a rigid airfoil supported by nonlinear flexural and torsional springs is placed in an incompressible air flow and subjected to a harmonic base excitation in the plunge direction. Under this combined loading, the airfoil undergoes complex motions which strain a piezoelectric element producing a voltage across an electric load. To capture the qualitative behavior of the harvester, a five-dimensional lumped-parameter model which adopts nonlinear quasi-steady aerodynamics is used. A center manifold reduction is implemented to reduce the full model into one nonlinear first-order ordinary differential equation. The normal form of the reduced system is then derived to study slow modulation of the response amplitude and phase near the flutter instability. Below the flutter speed, the response of the harvester is observed to be always periodic with the air flow serving to amplify the influence of the base excitation on the response by reducing the effective stiffness of the system, and hence, increasing the RMS output power. Beyond the flutter speed, two distinct regions are observed. The first occurs when the base excitation is small and/or when the excitation frequency is not close to the frequency of the self-sustained oscillations induced by the flutter instability. In this case, the response of the harvester is two-period quasiperiodic with amplitude modulation due to the presence of two incommensurate frequencies in the response. This amplitude modulation reduces the RMS output power. In the second region, the amplitude of excitation is large enough to eliminate the quasiperiodic response by causing the two frequencies to lock into each other. In this region, the response becomes periodic and the output power increases exhibiting little dependence on the base excitation.

Bibo, Amin; Daqaq, Mohammed F.

2013-09-01

326

Study of vibrational energy transfer at a liquid tin surface  

NASA Astrophysics Data System (ADS)

Single collision vibrational energy transfer for a canonical ensemble (T=300K) of cyclobutene molecules at a liquid tin surface was studied at temperatures from 500K to 775K. Transport above the reaction threshold for isomerization to butadiene was used as the criterion for efficiency of vibrational energy accommodation. The surface was found to function as a strong collider below 550 K. Experiments both above and below the freezing point revealed no discontinuity in the vibrational accommodation efficiency.

Nilsson, W. B.; Rabinovitch, B. S.

1984-08-01

327

Studying the effects of temperature on energy harvesting using pre-stressed piezoelectric diaphragms  

NASA Astrophysics Data System (ADS)

Energy harvesting is a process in which energy which would otherwise be wasted is captured, stored and then used to power a system. Devices having such capabilities enjoy an extended life particularly advantageous in systems with limited accessibility, such as biomedical implants and structure embedded micro and wireless sensors. A viable family of materials for this purpose is piezoelectric materials because of their inherent ability to convert vibrations into electrical energy. This paper uses a type of pre-stressed PZT-5A Unimorph called Thunder®, to actively convert mechanical vibrations into useable power. The effects of temperature, 20-100°C, pressure, 138-345kPa, frequency, 2-5Hz, and load resistance, 0.47-2.0M?, on the energy harvesting potential of the device are studied. The data obtained is analyzed using statistical techniques that assess the significance of the factors being studied. Results showed that the effect of temperature by itself on the voltage, AC or DC, and power generation was seen to be not significant. In combination with other factors such as pressure, frequency, and load resistance however, the temperature effect becomes statistically significant. These interaction effects tend to reduce voltage and power conversion. The maximum DC voltage and power were calculated as 108V and 11641?W at 20°C, 275.8kPa, 2.5Hz and 2M?. Similarly the greatest peak to peak AC voltage of 338V was also measured at 20°C and 2.5Hz. Based on the geometry of the piezoelectric diaphragm the most power density was evaluated to be 15?W/mm 3.

Mane, Poorna; Mossi, Karla; Green, Christopher; Bryant, Robert

2007-04-01

328

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

NASA Astrophysics Data System (ADS)

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

Zeng, Peng

329

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

NASA Astrophysics Data System (ADS)

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

Yildiz, Faruk

330

Modeling and design of Galfenol unimorph energy harvester  

NASA Astrophysics Data System (ADS)

Magnetostrictive iron-gallium alloys, known as Galfenol, are a recent class of smart materials with potential in energy harvesting applications. Unimorph energy harvesters consisting of a Galfenol beam bonded to a passive substrate are simple and effective, but advanced models are lacking for these smart devices. This study presents a finite element model for Galfenol unimorph harvester systems. Experiments considering various design parameters such as pick up coil size, load resistance, beam thickness ratio, and bias magnetic field strength are conducted to guide and validate the modeling effort. If the free length of the Galfenol unimorph beam is considered as the effective length, the maximum average power density, peak power density, and open-circuit voltage amplitude achieved in experiments are 13.97 mW/cm3, 35.51 mW/cm3, and 0.66 V, respectively. By only considering the length of Galfenol surrounded by the pickup coil, the maximum average power density and peak power density are 23.66 mW/cm3 and 60.14 mW/cm3, respectively.

Deng, Zhangxian; Dapino, Marcelo J.

2014-04-01

331

Experimental and numerical study of cellulose-based electro-active paper energy harvester  

NASA Astrophysics Data System (ADS)

In this present study experimental and finite element analysis of cellulose based electro-active paper energy harvester is presented. Electro-active paper coated with metal electrode is a smart form of cellulose and exhibit piezoelectric effect. Specimens were prepared by depositing electrodes on both sides of the cellulose film. A 50 mm x 50 mm cellulose film coated with aluminum electrodes was bonded on 100 mm x 50 mm x 1 mm aluminum host structure. The voltage output to input acceleration frequency response across a load resistor of 1 M? is recorded by conventional energy harvesting experimental setup at the fundamental vibration mode of the EAPap cantilever beam. A coupled piezoelectric-circuit finite element model is developed in which load resistor is directly connected to energy scavenging device. Voltage output FRF is measured for the cases, without proof mass, and by adding a 2 grams proof mass near the tip of the cantilever. The experimental voltage FRF value is 7.6 V/g at 75.1 Hz and is improved to 13.8 V/g at 62.2 Hz when a stainless steel proof mass of 2 grams is added. The presented CPC-FEM model results agree reasonably well with the experimental results. Despite the fact that the electro-mechanical coupling coefficient of electro-active paper is lower than other available piezoelectric materials, it is biocompatible, cheap and naturally occurring polymeric material. It is also very flexible and posses similar piezoelectric characteristics such a PVDF which inspire to use EAPap in energy harvesting applications.

Abas, Zafar; Kim, Heung Soo; Zhai, Lindong; Kim, Jaehwan

2014-04-01

332

Experimental investigation of galloping piezoelectric energy harvesters with square bluff bodies  

NASA Astrophysics Data System (ADS)

In this paper, both a baseline galloping piezoelectric energy harvester (GPEH) with a square bluff body and an improved GPEH with an impact bump stop are tested in a wind tunnel in order to determine the system damping, electrical response and limit cycle oscillation (LCO) amplitude. In the baseline GPEH, harvested voltage, LCO amplitude and damping ratio vary with wind velocity and electrical load. They all increase with increasing wind velocity under the same electrical load. Under each wind velocity, the damping ratio increases from the short circuit load, reaches a peak value at the electrical load resulting in a maximum voltage, and reduces the value at the open circuit load. The LCO amplitude shows the opposite trend compared to the damping case. It decreases as the electrical resistance load increases and reaches the minimum value when the damping ratio is highest. A resistance load of 100 kΩ yields a maximum peak power output. The impact stop is introduced to reduce bending stresses and improve the fatigue life of the baseline GPEH. The performance of the improved GPEH depends on the stop design parameters such as gap size, stop location and contact area. Comprehensive tests were conducted to investigate the effect of each parameter on the performance of the improved GPEH and an optimal bump stop configuration was determined. Compared to the expected proportional reduction in both electrical and structural responses, a maximum 70% reduction in LCO amplitude and only a maximum 20% reduction in harvested voltage are achieved in our optimal improved GPEH. The time variable and motion dependent aerodynamic forces acting on the bluff body could contribute to this. In summary, comprehensive experimental evaluations were conducted to characterize the performance of both baseline GPEHs and improved GPEHs. The baseline GPEH service life can be significantly improved by incorporating an impact bump stop. The improved GPEH design provides a practical solution to harvest electricity from wind-induced vibration.

Ewere, Felix; Wang, Gang; Cain, Brian

2014-10-01

333

Vibrational energy redistribution in glyoxal following internal conversion  

E-print Network

pumped excitation/ detection vacuum chamber is attached. Inside the cross is the beam source, whichVibrational energy redistribution in glyoxal following internal conversion R. Naaman,a) D. M 4 June 1979; accepted 10 August 1979) The vibrational redistribution of energy following internal

Zare, Richard N.

334

Modelling excitonic-energy transfer in light-harvesting complexes  

E-print Network

The theoretical and experimental study of energy transfer in photosynthesis has revealed an interesting transport regime, which lies at the borderline between classical transport dynamics and quantum-mechanical interference effects. Dissipation is caused by the coupling of electronic degrees of freedom to vibrational modes and leads to a directional energy transfer from the antenna complex to the target reaction-center. The dissipative driving is robust and does not rely on fine-tuning of specific vibrational modes. For the parameter regime encountered in the biological systems new theoretical tools are required to directly compare theoretical results with experimental spectroscopy data. The calculations require to utilize massively parallel graphics processor units (GPUs) for efficient and exact computations.

Kramer, Tobias

2014-01-01

335

Nano-cluster-enhanced high-performance perfluoro-polymer electrets for energy harvesting  

NASA Astrophysics Data System (ADS)

Development of high-performance electret materials is required to obtain a large power output of the electrostatic vibration-driven energy harvesters. In this study, by introducing aminosilane derivatives into CYTOP-based perfluorinated polymer film, we have successfully formed nano-clusters containing the organic siloxanes in the polymer electrets. Using small-angle x-ray scattering, tapping mode AFM and SEM analysis, the existence of such nano-clusters has been directly observed in the CYTOP film. It is suggested that the observed nano-clusters serve as the charge trap site and enhance the surface charge density and the thermal stability of the trapped charges. As a polymer electret, an extremely high surface charge potential of -1.6 kV with the 15 µm thick film has been obtained under the optimum condition of corona charging.

Kashiwagi, Kimiaki; Okano, Kuniko; Miyajima, Tatsuya; Sera, Yoichi; Tanabe, Noriko; Morizawa, Yoshitomi; Suzuki, Yuji

2011-12-01

336

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

NASA Astrophysics Data System (ADS)

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

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

2011-09-01

337

Lowest of AC-DC power output for electrostrictive polymers energy harvesting systems  

NASA Astrophysics Data System (ADS)

Advances in technology led to the development of electronic circuits and sensors with extremely low electricity consumption. At the same time, structural health monitoring, technology and intelligent integrated systems created a need for wireless sensors in hard to reach places in aerospace vehicles and large civil engineering structures. Powering sensors with energy harvesters eliminates the need to replace batteries on a regular basis. Scientists have been forced to search for new power source that are able to harvested energy from their surrounding environment (sunlight, temperature gradients etc.). Electrostrictive polymer belonging to the family of electro-active polymers, offer unique properties for the electromechanical transducer technology has been of particular interest over the last few years in order to replace conventional techniques such as those based on piezoelectric or electromagnetic, these materials are highly attractive for their low-density, with large strain capability that can be as high as two orders of magnitude greater than the striction-limited, rigid and fragile electroactive ceramics. Electrostrictive polymers sensors respond to vibration with an ac output signal, one of the most important objectives of the electronic interface is to realize the required AC-DC conversion. The goal of this paper is to design an active, high efficiency power doubler converter for electrostrictive polymers exclusively uses a fraction of the harvested energy to supply its active devices. The simulation results show that it is possible to obtain a maximum efficiency of the AC-DC converter equal to 80%. Premiliminary experimental measurements were performed and the results obtained are in good agreement with simulations.

Meddad, Mounir; Eddiai, Adil; Hajjaji, Abdelowahed; Guyomar, Daniel; Belkhiat, Saad; Boughaleb, Yahia; Chérif, Aida

2013-11-01

338

Impulse excitation of piezoelectric bimorphs for energy harvesting: a dimensionless model  

NASA Astrophysics Data System (ADS)

Energy harvesting (EH) is a multidisciplinary research area, involving physics, materials science and engineering, with the objective of providing renewable sources of power sufficient to operate targeted low-power applications. Piezoelectric transducers are often used for inertial vibrational as well as direct excitation EH. However, due to the stiffness of the most common material (PZT), compact and light-weight harvesters have high resonant frequencies, making them inefficient at extracting low-frequency power from the environment. The technique of frequency up-conversion, in the form of either plucking or impulse excitation, aims to bridge this frequency gap. In this paper, the technique is modelled analytically with focus on impulse excitation via impact or shock. An analytical model is developed in a standard way starting from the Euler-Bernoulli beam equations adapted to a piezoelectric bimorph. A set of dimensionless variables and parameters is defined and a system of differential equations derived. Here the system is solved numerically for a wide range of the two group parameters present, covering piezoelectric coupling strength between PVDF and PMN-PT. One major result is that the strength of the coupling strongly affects the timescale of the process, but has only a minor effect on the total energy converted. The model can be readily adapted to different excitation profiles.

Pozzi, Michele

2014-04-01

339

Experimental Testing and Model Validation for Ocean Wave Energy Harvesting Buoys  

E-print Network

Experimental Testing and Model Validation for Ocean Wave Energy Harvesting Buoys Douglas A. Gemme1 are presented for numerical simulations and field experiments using point absorption ocean wave energy and experimental data. Index Terms ­ energy conversion, wave energy harvesting, linear generator, ocean energy

Grilli, Stéphan T.

340

Lumped model of bending electrostrictive transducers for energy harvesting  

NASA Astrophysics Data System (ADS)

Electroactive polymers, and more particular dielectric electrostrictive polymers, have been of great interest over the last decade thanks to their flexibility, easy processing, conformability, and relatively low cost. Their application as actuators, sensors, or energy harvesters suits very well to systems that require high strain. In particular, bending devices are an important application field of such materials, especially when dealing with devices subjected to air or liquid flows. Nevertheless, the design of such devices and their associated electrical interface still requires starting from the local aspects of the electrostrictive effect. In order to provide a simple yet efficient design tool, this paper exposes a simple lumped model for electrostrictive dielectric devices working under flexural solicitation. Based on the analysis of the converted energy with respect to the provided energy, it is shown that electrostrictive systems can easily be reduced to a simple spring-mass-damper system with a quadratic dependence to the applied voltage on the mechanical side and to a current source controlled by the applied voltage with a capacitive internal impedance on the electrical side. Experimental measurements carried out to evaluate the mechanical to electrical conversion effect as well as the energy harvesting abilities in such systems also validate the proposed approach.

Lallart, Mickaël; Wang, Liuqing; Richard, Claude; Petit, Lionel; Guyomar, Daniel

2014-09-01

341

Vibrational energy transfer in shocked molecular crystals.  

PubMed

We consider the process of establishing thermal equilibrium behind an ideal shock front in molecular crystals and its possible role in initiating chemical reaction at high shock pressures. A new theory of equilibration via multiphonon energy transfer is developed to treat the scattering of shock-induced phonons into internal molecular vibrations. Simple analytic forms are derived for the change in this energy transfer at different Hugoniot end states following shock compression. The total time required for thermal equilibration is found to be an order of magnitude or faster than proposed in previous work; in materials representative of explosive molecular crystals, equilibration is predicted to occur within a few picoseconds following the passage of an ideal shock wave. Recent molecular dynamics calculations are consistent with these time scales. The possibility of defect-induced temperature localization due purely to nonequilibrium phonon processes is studied by means of a simple model of the strain field around an inhomogeneity. The specific case of immobile straight dislocations is studied, and a region of enhanced energy transfer on the order of 5 nm is found. Due to the rapid establishment of thermal equilibrium, these regions are unrelated to the shock sensitivity of a material but may allow temperature localization at high shock pressures. Results also suggest that if any decomposition due to molecular collisions is occurring within the shock front itself, these collisions are not enhanced by any nonequilibrium thermal state. PMID:20078172

Hooper, Joe

2010-01-01

342

Ambient wind energy harvesting using cross-flow fluttering  

NASA Astrophysics Data System (ADS)

In this experimental study, we propose and test a bioinspired piezo-leaf architecture which converts wind energy into electrical energy by wind-induced fluttering motion. While conventional fluttering devices are arranged in parallel with the flow direction, here we explore a dangling cross-flow stalk arrangement. This architecture amplifies the vibration by an order of magnitude, making it appropriate for low-cost organic piezomaterials. We fabricated prototypes using flexible piezoelectric materials as stalks and polymer film as leaves. A series of experiments demonstrated a peak output power of approximately 600 ?W and maximum power density of approximately 2 mW/cm3 from a single leaf.

Li, Shuguang; Yuan, Jianping; Lipson, Hod

2011-01-01

343

Electrode effects of a cellulose-based electro-active paper energy harvester  

NASA Astrophysics Data System (ADS)

The possibility of cellulose-based electro-active paper (EAPap) as a vibrational energy transducer was investigated in this paper. Thin cellulose EAPap film specimens were prepared by the regenerating process. Three different metal electrodes of gold, silver and aluminum were deposited on a 50 × 50 mm2 cellulose film using a thermal evaporator. An aluminum cantilever beam was used as a vibrational bender and EAPap was attached close to the root of the cantilever beam. The voltage output of the EAPap was measured under harmonic base excitation of the cantilever beam. The EAPap with aluminum electrode provided the largest open circuit voltage output compared to those with gold or silver electrodes. The output voltages of the EAPap increased linearly with increase of the area of the electrodes. The output voltages also increased with increasing input acceleration but became saturated at a certain magnitude. From the experimental results, we conclude that EAPap with metal electrodes can be used as a flexible energy harvesting transducer by external mechanical stress, and the output voltage is related to the electrode material due to its work function.

Abas, Zafar; Kim, Heung Soo; Zhai, Lindong; Kim, Jaehwan; Kim, Joo-Hyung

2014-07-01

344

Segmentally structured disk triboelectric nanogenerator for harvesting rotational mechanical energy.  

PubMed

We introduce an innovative design of a disk triboelectric nanogenerator (TENG) with segmental structures for harvesting rotational mechanical energy. Based on a cyclic in-plane charge separation between the segments that have distinct triboelectric polarities, the disk TENG generates electricity with unique characteristics, which have been studied by conjunction of experimental results with finite element calculations. The role played by the segmentation number is studied for maximizing output. A distinct relationship between the rotation speed and the electrical output has been thoroughly investigated, which not only shows power enhancement at high speed but also illuminates its potential application as a self-powered angular speed sensor. Owing to the nonintermittent and ultrafast rotation-induced charge transfer, the disk TENG has been demonstrated as an efficient power source for instantaneously or even continuously driving electronic devices and/or charging an energy storage unit. This work presents a novel working mode of TENGs and opens up many potential applications of nanogenerators for harvesting even large-scale energy. PMID:23656350

Lin, Long; Wang, Sihong; Xie, Yannan; Jing, Qingshen; Niu, Simiao; Hu, Youfan; Wang, Zhong Lin

2013-06-12

345

Semi-flexible bimetal-based thermal energy harvesters  

NASA Astrophysics Data System (ADS)

This paper introduces a new semi-flexible device able to turn thermal gradients into electricity by using a curved bimetal coupled to an electret-based converter. In fact, a two-step conversion is carried out: (i) a curved bimetal turns the thermal gradient into a mechanical oscillation that is then (ii) converted into electricity thanks to an electrostatic converter using electrets in Teflon®. The semi-flexible and low-cost design of these new energy converters pave the way to mass production over large areas of thermal energy harvesters. Raw output powers up to 13.46 ?W per device were reached on a hot source at 60?°C with forced convection. Then, a DC-to-DC flyback converter has been sized to turn the energy harvesters’ raw output powers into a viable supply source for an electronic circuit (DC@3 V). At the end, 10 ?W of directly usable output power were reached with 3 devices, which is compatible with wireless sensor network powering applications.

Boisseau, S.; Despesse, G.; Monfray, S.; Puscasu, O.; Skotnicki, T.

2013-02-01

346

Electromechanical fatigue in IPMC under dynamic energy harvesting conditions  

NASA Astrophysics Data System (ADS)

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

Krishnaswamy, Arvind; Roy Mahapatra, D.

2011-04-01

347

An energy harvesting system surveyed for a variety of unattended electronic applications  

NASA Astrophysics Data System (ADS)

All energy-harvesting schemes require some form of "intermediate" storage - batteries or capacitors that reservoir energy harvested from the environment. There are a number of reasons for this requirement. Ambient energy fluctuates and intermediate storage smoothes out the impact of these fluctuations on the power delivered to a load. In addition, energy must be "conditioned" to be useful in a given application. It must be set to a certain voltage or made capable of delivering a desired current to load. In this article, a complete energy harvesting system including storage and conditioning electronics is described with a concentration on radio frequency (RF) harvesting. The system is capable of harvesting energy from a commercially available hand-held communication device, and exhibits an overall energy harvesting efficiency of 13.2%. Several potential applications have been investigated based on the performance of this system. Highlighted example applications include power sources for nodes in an architectural structural integrity monitor, and limb prosthesis.

Zhao, Wei; Choi, Kwangsik; Bauman, Scott; Salter, Thomas; Lowy, Daniel A.; Peckerar, Martin; Khandani, Mehdi Kalantari

2013-01-01

348

Power inversion design for ocean wave energy harvesting  

NASA Astrophysics Data System (ADS)

The needs for energy sources are increasing day by day because of several factors, such as oil depletion, and global climate change due to the higher level of CO2, so the exploration of various renewable energy sources is very promising area of study. The available ocean waves can be utilized as free source of energy as the water covers 70% of the earth surface. This thesis presents the ocean wave energy as a source of renewable energy. By addressing the problem of designing efficient power electronics system to deliver 5 KW from the induction generator to the grid with less possible losses and harmonics as possible and to control current fed to the grid to successfully harvest ocean wave energy. We design an AC-DC full bridge rectifier converter, and a DC-DC boost converter to harvest wave energy from AC to regulated DC. In order to increase the design efficiency, we need to increase the power factor from (0.5-0.6) to 1. This is accomplished by designing the boost converter with power factor correction in continues mode with RC circuit as an input to the boost converter power factor correction. This design results in a phase shift between the input current and voltage of the full bridge rectifier to generate a small reactive power. The reactive power is injected to the induction generator to maintain its functionality by generating a magnetic field in its stator. Next, we design a single-phase pulse width modulator full bridge voltage source DC-AC grid-tied mode inverter to harvest regulated DC wave energy to AC. The designed inverter is modulated by inner current loop, to control current injected to the grid with minimal filter component to maintain power quality at the grid. The simulation results show that our design successfully control the current level fed to the grid. It is noteworthy that the simulated efficiency is higher than the calculated one since we used an ideal switch in the simulated circuit.

Talebani, Anwar N.

349

Thermoelectric energy harvesting for a solid waste processing toilet  

NASA Astrophysics Data System (ADS)

Over 2.5 billion people do not have access to safe and effective sanitation. Without a sanitary sewer infrastructure, self-contained modular systems can provide solutions for these people in the developing world and remote areas. Our team is building a better toilet that processes human waste into burnable fuel and disinfects the liquid waste. The toilet employs energy harvesting to produce electricity and does not require external electrical power or consumable materials. RTI has partnered with Colorado State University, Duke University, and Roca Sanitario under a Bill and Melinda Gates Foundation Reinvent the Toilet Challenge (RTTC) grant to develop an advanced stand-alone, self-sufficient toilet to effectively process solid and liquid waste. The system operates through the following steps: 1) Solid-liquid separation, 2) Solid waste drying and sizing, 3) Solid waste combustion, and 4) Liquid waste disinfection. Thermoelectric energy harvesting is a key component to the system and provides the electric power for autonomous operation. A portion of the exhaust heat is captured through finned heat-sinks and converted to electricity by thermoelectric (TE) devices to provide power for the electrochemical treatment of the liquid waste, pumps, blowers, combustion ignition, and controls.

Stokes, C. David; Baldasaro, Nicholas G.; Bulman, Gary E.; Stoner, Brian R.

2014-06-01

350

Energy Aware Dynamic Voltage and Frequency Selection for Real-Time Systems with Energy Harvesting  

Microsoft Academic Search

In this paper, an energy aware dynamic voltage and frequency selection (EA-DVFS) algorithm is proposed. The EA-DVFS algorithm adjusts the processor's behavior depending on the summation of the stored energy and the harvested energy in a future duration. Specifically, if the system has sufficient energy, tasks are executed at full speed; otherwise, the processor slows down task execution to save

Shaobo Liu; Qinru Qiu; Qing Wu

2008-01-01

351

Modeling coherent excitation energy transfer in photosynthetic light harvesting systems  

NASA Astrophysics Data System (ADS)

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

Huo, Pengfei

352

Analysis and modeling of a piezoelectric energy harvester for powering a wireless sensor  

NASA Astrophysics Data System (ADS)

The work presented aims at modeling, designing and implementing an energy harvesting system capable of generating electricity from environmental vibrations. Subject of the analysis is a piezoelectric bimorph; this particular transducer, composed of two layers of piezoceramic material, is clamped in a cantilever configuration and is dynamically bent due to vibrations. The resulting deformation ensures enough current to power the electronic circuit of a wireless sensor. An analytical model is adopted, that describes the dynamics of the mechanical system using an electrical duality. In particular the coupling of the variables is represented by an equivalent transformer. The obtainable voltage and power are investigated, focusing on the influence of the electric load on the performance of the conversion process. In addition, to overcome the limitations related to the analytical study, a finite element model is provided, capable of simulating the behavior of the system more accurately. Finally, both models are validated by means of experimental tests, showing the mutual influence between the mechanical and the electrical domain.

Bassetti, Marco; Braghin, Francesco; Milani, Damiano; Ripamonti, Francesco; Tomasini, Gisella

2013-04-01

353

Improvement of Pyroelectric Cells for Thermal Energy Harvesting  

PubMed Central

This study proposes trenching piezoelectric (PZT) material in a thicker PZT pyroelectric cell to improve the temperature variation rate to enhance the efficiency of thermal energy-harvesting conversion by pyroelectricity. A thicker pyroelectric cell is beneficial in generating electricity pyroelectrically, but it hinders rapid temperature variations. Therefore, the PZT sheet was fabricated to produce deeper trenches to cause lateral temperature gradients induced by the trenched electrode, enhancing the temperature variation rate under homogeneous heat irradiation. When the trenched electrode type with an electrode width of 200 ?m and a cutting depth of 150 ?m was used to fabricate a PZT pyroelectric cell with a 200 ?m thick PZT sheet, the temperature variation rate was improved by about 55%. Therefore, the trenched electrode design did indeed enhance the temperature variation rate and the efficiency of pyroelectric energy converters. PMID:22368484

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

2012-01-01

354

Flutter-driven triboelectrification for harvesting wind energy  

NASA Astrophysics Data System (ADS)

Technologies to harvest electrical energy from wind have vast potentials because wind is one of the cleanest and most sustainable energy sources that nature provides. Here we propose a flutter-driven triboelectric generator that uses contact electrification caused by the self-sustained oscillation of flags. We study the coupled interaction between a fluttering flexible flag and a rigid plate. In doing so, we find three distinct contact modes: single, double and chaotic. The flutter-driven triboelectric generator having small dimensions of 7.5 × 5?cm at wind speed of 15?ms?1 exhibits high-electrical performances: an instantaneous output voltage of 200?V and a current of 60??A with a high frequency of 158?Hz, giving an average power density of approximately 0.86?mW. The flutter-driven triboelectric generation is a promising technology to drive electric devices in the outdoor environments in a sustainable manner.

Bae, Jihyun; Lee, Jeongsu; Kim, Seongmin; Ha, Jaewook; Lee, Byoung-Sun; Park, Youngjun; Choong, Chweelin; Kim, Jin-Baek; Wang, Zhong Lin; Kim, Ho-Young; Park, Jong-Jin; Chung, U.-In

2014-09-01

355

Electrostatic vibration-to-electric energy conversion  

E-print Network

Ultra-Low-Power electronics can perform useful functions with power levels as low as 170 nW. This makes them amenable to powering from ambient sources such as vibration. In this case, they can become autonomous. Motivated ...

Mur Miranda, José Oscar, 1972-

2004-01-01

356

Vibration Isolation of a Locomotive Mounted Energy Storage Flywheel  

E-print Network

Utilizing flywheels to store and reuse energy from regenerative braking on locomotives is a new technology being developed in the Vibration Control and Electromechanics Lab at Texas A&M. This thesis focuses on the motion analysis of a locomotive...

Zhang, Xiaohua

2011-02-22

357

Three-dimensional magnetic energy harvester applied for locomotive devices  

NASA Astrophysics Data System (ADS)

An innovative tri-axes micro-power receiver is proposed and studied for wireless magnetic energy transmission. The tri-axes micro-power receiver mainly consists of two sets of 3D micro-solenoids and one set of planar micro-coils in which individually iron core is all embedded. The three sets of micro-coils/micro-solenoids are designed to be orthogonal to each other. Therefore, no matter which direction the input magnetic flux is present along, the supplied magnetic energy can be harvested and transformed into electric power by the proposed micro-power receiver in wireless sense. Not only dead zone of receiving power is greatly reduced, but also transformation efficiency of magnetic energy into electric power can be much enhanced. By Biot-Savart law and Faraday's law, the mathematical description upon power transmission from transmitter to receiver is developed. By employing commercial software, Ansoft Maxwell, based on finite element method, the estimation error on power transmission by mathematical description is revealed. Besides, the preliminary simulation results by Ansoft Maxwell show that the proposed micro-power receiver can efficiently harvest the energy supplied by magnetic power source. The design parameters of tri-axes micro-receiver are hence examined and verified for follow-up fabrication. At last, for the MEMS process, the isotropic etching technique is employed to micro-machine the inverse-trapezoid fillister so that the copper wire can be successfully electroplated. The adhesion between micro-coils and fillister is hence much enhanced as well.

Tsai, N.-C.; Hsu, S.-L.

2012-01-01

358

Energy harvesting and wireless energy transmission for powering SHM sensor nodes  

SciTech Connect

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

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

2009-01-01

359

Approximate Response Time for Fixed Priority Real-Time Systems with Energy-Harvesting  

E-print Network

Approximate Response Time for Fixed Priority Real-Time Systems with Energy-Harvesting Yasmina sufficient schedulability tests for fixed-priority pre-emptive scheduling of a real-time system under energy constraints. In this problem, energy is harvested from the ambient environment and used to replenish a storage

Boyer, Edmond

360

Optimization Intensive Energy Harvesting Mahsan Rofouei, Mohammad Ali Ghodrat, Miodrag Potkonjak  

E-print Network

Optimization Intensive Energy Harvesting Mahsan Rofouei, Mohammad Ali Ghodrat, Miodrag Potkonjak of primary limiting factors of MSs is their energy sensitivity. In order to overcome this limitation, we have developed an optimization intensive approach for energy harvesting. Our goal is to size and position

Potkonjak, Miodrag

361

Adapting Task Utility in Externally Triggered Energy Harvesting Wireless Sensing Systems  

E-print Network

Adapting Task Utility in Externally Triggered Energy Harvesting Wireless Sensing Systems Jamie tajana@ucsd.edu Abstract--Energy harvesting sensor nodes eliminate the need for post-deployment physical the utility of their tasks to accommodate the energy availability. For example, on sunny days, a solar

Simunic, Tajana

362

Impact of Mobile Transmitter Sources on Radio Frequency Wireless Energy Harvesting  

E-print Network

1 Impact of Mobile Transmitter Sources on Radio Frequency Wireless Energy Harvesting Antonio Organization, Tata Consultancy Services, India. Abstract--Wireless energy harvesting sensor networks consti battery resource, but are able to re-charge themselves through directed electromagnetic energy transfer

Sanyal, Sugata

363

Adaptive Control of Duty Cycling in Energy-Harvesting Wireless Sensor Networks  

E-print Network

Adaptive Control of Duty Cycling in Energy-Harvesting Wireless Sensor Networks Christopher M wireless sensor network deployments are using harvested environmental energy to extend system lifetime. Because the temporal profiles of such energy sources exhibit great variability due to dynamic weather

Massachusetts at Amherst, University of

364

A Full-Wave Rectifier for Interfacing with Multi-Phase Piezoelectric Energy Harvesters*  

E-print Network

A Full-Wave Rectifier for Interfacing with Multi-Phase Piezoelectric Energy Harvesters* N. J: TECHNOLOGY TRENDS: Energy Sources and Energy Harvesting Abstract A full-wave rectifier has been fabricated-electrode piezoelectric transducer to be rectified with reduced output ripple. The rectifier has a measured power

Hurst, Paul J.

365

Task scheduling in an energy harvesting WSN for Structural Health Monitoring Literature Survey  

E-print Network

associated with specific rewards. The energy harvesting rate in the future K 'frames' is calculated using regression based algorithm that relates the energy consumption, execution time and data accuracyTask scheduling in an energy harvesting WSN for Structural Health Monitoring Literature Survey

Simunic, Tajana

366

Ambient-RF-Energy-Harvesting Sensor Node with Capacitor-Leakage-Aware Duty Cycle Control  

E-print Network

methods for energy harvesting are discussing solar panels, wind power, and piezoelectric devices of the operation reliability and leakage reduction. I. INTRODUCTION Energy harvesting technologies such as solar panels, piezoelectric devices, thermocouples, and RF energy scavengers are attracting a great deal

Tentzeris, Manos

367

Demo: Organic Solar Cell-equipped Energy Harvesting Active Networked Tag (EnHANT) Prototypes  

E-print Network

Demo: Organic Solar Cell-equipped Energy Harvesting Active Networked Tag (EnHANT) Prototypes GeraldHANT pro- totypes. The current EnHANT prototypes are integrated with novel custom in-house-developed energy harvesting, organic solar cells, ultra-low-power com- munications, ultra-wideband impulse radio, energy

Carloni, Luca

368

Optimal frequency for flow energy harvesting using flapping foils and its relation with wake instability  

Microsoft Academic Search

Inspired by the correlation between the propulsion efficiency of a flapping foil propeller and stability of the wake behind it (which leads to the optimal Strouhal number for propulsion), we numerically simulated a foil in energy harvesting mode, and investigated the relation between wake stability and the energy harvesting efficiency (defined as the portion of incoming flow energy extracted by

Qiang Zhu

2010-01-01

369

Nonlinear piezoelectricity in electroelastic energy harvesters: Modeling and experimental identification  

NASA Astrophysics Data System (ADS)

We propose and experimentally validate a first-principles based model for the nonlinear piezoelectric response of an electroelastic energy harvester. The analysis herein highlights the importance of modeling inherent piezoelectric nonlinearities that are not limited to higher order elastic effects but also include nonlinear coupling to a power harvesting circuit. Furthermore, a nonlinear damping mechanism is shown to accurately restrict the amplitude and bandwidth of the frequency response. The linear piezoelectric modeling framework widely accepted for theoretical investigations is demonstrated to be a weak presumption for near-resonant excitation amplitudes as low as 0.5 g in a prefabricated bimorph whose oscillation amplitudes remain geometrically linear for the full range of experimental tests performed (never exceeding 0.25% of the cantilever overhang length). Nonlinear coefficients are identified via a nonlinear least-squares optimization algorithm that utilizes an approximate analytic solution obtained by the method of harmonic balance. For lead zirconate titanate (PZT-5H), we obtained a fourth order elastic tensor component of c1111p=-3.6673×1017 N/m2 and a fourth order electroelastic tensor value of e3111=1.7212×108 m/V.

Stanton, Samuel C.; Erturk, Alper; Mann, Brian P.; Inman, Daniel J.

2010-10-01

370

Energy-based comparison of various controllers for vibration suppression using piezoceramics  

NASA Astrophysics Data System (ADS)

The large-scale and light-weight design trend in aircraft and spacecraft results in extremely flexible structures with lowfrequency vibration modes. Suppression of undesired vibrations in such flexible structures with limited energy is becoming an important design problem to develop energy-autonomous controllers powered using the harvested ambient energy. The objective of this paper is to compare different control laws to suppress low-frequency vibrations using the minimum actuation energy for the same system and under the same design constraint (identical settling time for free vibrations). The vibration suppression performance of four active control systems as well as their hybrid versions employing a switching technique are presented and compared. The control systems compared here are a Positive Position Feedback (PPF) controller, a Proportional Integral Derivative (PID) controller, a nonlinear controller (with a second-order nonlinear term multiplying the position and velocity feedback to create variable damping), a Linear Quadratic Regulator (LQR) controller and their hybrid versions integrating a bang-bang control law (on-off control) with each of these controllers. Experimental results are presented for a thin cantilevered beam with a piezoceramic transducer controlled by these eight controllers with a focus on the fundamental vibration mode under transverse free vibrations and the control energy requirements are compared. Experiments results reveal that all the controllers reduce the vibration settling time to 0.85s as a design constraint (which is 92.3% of the open-loop settling time: 10.9s). The average actuation power input provided to the piezoceramic transducer in each case is obtained for the time current and voltage measurements until the settling time. Comparisons show that the switching technology reduces significant actuation power requirement, so that all the hybrid control systems require much less power than their conventional versions. Especially, the hybrid bang-bang-nonlinear controller requires 67% less power than the conventional nonlinear controller. In order to verify this statement, the actuation current is theoretically calculated through piezo-capacitance using voltage measurements to check out the average power estimation. The theoretical checking out provides the same results with slightly error, which can be explained by measurement errors.

Wang, Ya; Inman, Daniel J.

2011-03-01

371

Analysis of thermal energy harvesting using ferromagnetic materials  

NASA Astrophysics Data System (ADS)

This Letter aims at giving a preliminary investigation of the thermal energy harvesting capabilities of a technique using the temperature-dependent permeability of ferromagnetic materials. The principles lie in the modification of the magnetic field caused by the variation of the permeability due to the temperature change, hence generating a voltage across a coil surrounding the circuit. The technique can be made truly passive by the use of magnets for applying bias magnetic field. Theoretical results, validated by experimental measurements, show a voltage output of 1.2 mV at optimal load of 2 ? under 60 K temperature variation in 5 s (with a maximum slope of 25 K s-1). Further improvements, such as the use of low resistivity coil and magnet with high remnant magnetic field, indicate that it is possible to convert up to 7.35 ?J cm-3 K-2 cycle-1.

Lallart, Mickaël; Wang, Liuqing; Sebald, Gaël; Petit, Lionel; Guyomar, Daniel

2014-09-01

372

Nondestructive methods of integrating energy harvesting systems for highway bridges  

NASA Astrophysics Data System (ADS)

Designing an attachment structure that is both novel and meets the system requirements can be a difficult task especially for inexperienced designers. This paper presents a design methodology for concept generation of a "parent/child" attachment system. The "child" is broadly defined as any device, part, or subsystem that will attach to any existing system, part, or device called the "parent." An inductive research process was used to study a variety of products, patents, and biological examples that exemplified the parent/child system. Common traits among these products were found and categorized as attachment principles in three different domains: mechanical, material, and field. The attachment principles within the mechanical domain and accompanying examples are the focus of this paper. As an example of the method, a case study of generating concepts for a bridge mounted wind energy harvester using the mechanical attachment principles derived from the methodology and TRIZ principles derived from Altshuller's matrix of contradictions is presented.

Inamdar, Sumedh; Zimowski, Krystian; Crawford, Richard; Wood, Kristin; Jensen, Dan

2012-04-01

373

Nondestructive methods of integrating energy harvesting systems with structures  

NASA Astrophysics Data System (ADS)

Designing an attachment structure that is both novel and meets the system requirements can be a difficult task especially for inexperienced designers. This paper presents a design methodology for concept generation of a "parent/child" attachment system. The "child" is broadly defined as any device, part, or subsystem that will attach to any existing system, part, or device called the "parent." An inductive research process was used to study a variety of products, patents, and biological examples that exemplified the parent/child system. Common traits among these products were found and categorized as attachment principles in three different domains: mechanical, material, and field. The attachment principles within the mechanical domain and accompanying examples are the focus of this paper. As an example of the method, a case study of generating concepts for a bridge mounted wind energy harvester using the mechanical attachment principles derived from the methodology and TRIZ principles derived from Altshuller's matrix of contradictions is presented.

Inamdar, Sumedh; Zimowski, Krystian; Crawford, Richard; Wood, Kristin; Jensen, Dan

2012-04-01

374

Energy Consumption Profile for Energy  

E-print Network

an important aspect. Energy that is harvested from sources, such as solar panels, vibration: Beyond the Solar Harvester--Is It a Viable Option?.321 12.4 Storing Harvested Energy] as well as custom motes running on solar energy. To accurately measure the energy consumption, we have

Langendoen, Koen

375

A self-powered sensor module using vibration-based energy generation for ubiquitous systems  

Microsoft Academic Search

A new architecture for ubiquitous sensor modules using vibration-based energy generation is proposed and the CMOS implementation of the proposed architecture is presented. The sensor module only scavenges vibration-based energy as energy source by using piezoelectric element to realize no batteries operation. The sensor module is used to supervise the vibration of machines and transfer the vibration signal discontinuously. Based

Jun Pan; Baocheng Xue; Y. Inoue

2005-01-01

376

Title: Adapting Performance in Energy Harvesting Wireless Sensor Networks for Structural Health Monitoring Applications  

E-print Network

Title: Adapting Performance in Energy Harvesting Wireless Sensor Networks for Structural Health health monitoring (SHM). While reducing the need for post-deployment physical human interaction, the plat-sensing platform, combines wireless communication with solar energy harvesting to provide long-lasting structural

Simunic, Tajana

377

Kinetic Energy Harvesting Using Piezoelectric and Electromagnetic Technologies—State of the Art  

Microsoft Academic Search

This paper presents the latest progress in kinetic energy harvesting for wide applications ranging from implanted devices and wearable electronic devices to mobile electronics and self-powered wireless network nodes. The advances in energy harvesters adopting piezoelectric and electromagnetic transduction mechanisms are presented. Piezoelectric generators convert mechanical strain on the active material to electric charge while electromagnetic generators make use of

Alireza Khaligh; Peng Zeng; Cong Zheng

2010-01-01

378

Modeling of dielectric elastomers: Design of actuators and energy harvesting devices  

E-print Network

Modeling of dielectric elastomers: Design of actuators and energy harvesting devices David L Keywords: Dielectric elastomers Large deformations Actuators Energy harvesting devices Finite-element method a b s t r a c t Dielectric elastomers undergo large deformations in response to an electric field

379

Energy Harvesting from Anti-Corrosion Power Sources Dept. of Biomed. Engineering  

E-print Network

, a boost converter is used to convert the low voltage levels of galvanic corrosion to that needed General Terms Design, Performance measurement Keywords Energy harvesting, galvanic corrosion, cathodicEnergy Harvesting from Anti-Corrosion Power Sources Sehwan Kim Dept. of Biomed. Engineering Dankook

Shinozuka, Masanobu

380

Industrial Solid-State Energy Harvesting: Mechanisms and Examples Matthew Kocoloski, Carnegie Mellon University  

E-print Network

Industrial Solid-State Energy Harvesting: Mechanisms and Examples Matthew Kocoloski, Carnegie, University of Dayton, Department of Mechanical and Aerospace Engineering ABSTRACT This paper explores the potential for solid-state energy harvesting in industrial applications. In contrast to traditional heat

Kissock, Kelly

381

Toward Large-Scale Energy Harvesting by a Nanoparticle-Enhanced Triboelectric Nanogenerator  

E-print Network

to harvest large-scale mechanical energy, such as footsteps, rolling wheels, wind power, and ocean waves. KEYWORDS: Triboelectric nanogenerator, large-scale, nanoparticle, wind power, ocean wave We are surrounded flow, and ocean waves, just to name a few. Research on mechanical energy harvesting falls into three

Wang, Zhong L.

382

Spectroscopic probes of vibrationally excited molecules at chemically significant energies  

SciTech Connect

This project involves the application of multiple-resonance spectroscopic techniques for investigating energy transfer and dissociation dynamics of highly vibrationally excited molecules. Two major goals of this work are: (1) to provide information on potential energy surfaces of combustion related molecules at chemically significant energies, and (2) to test theoretical modes of unimolecular dissociation rates critically via quantum-state resolved measurements.

Rizzo, T.R. [Univ. of Rochester, NY (United States)

1993-12-01

383

Review of pyroelectric thermal energy harvesting and new MEMs-based resonant energy conversion techniques  

NASA Astrophysics Data System (ADS)

Harvesting electrical energy from thermal energy sources using pyroelectric conversion techniques has been under investigation for over 50 years, but it has not received the attention that thermoelectric energy harvesting techniques have during this time period. This lack of interest stems from early studies which found that the energy conversion efficiencies achievable using pyroelectric materials were several times less than those potentially achievable with thermoelectrics. More recent modeling and experimental studies have shown that pyroelectric techniques can be cost competitive with thermoelectrics and, using new temperature cycling techniques, has the potential to be several times as efficient as thermoelectrics under comparable operating conditions. This paper will review the recent history in this field and describe the techniques that are being developed to increase the opportunities for pyroelectric energy harvesting. The development of a new thermal energy harvester concept, based on temperature cycled pyroelectric thermal-to-electrical energy conversion, are also outlined. The approach uses a resonantly driven, pyroelectric capacitive bimorph cantilever structure that can be used to rapidly cycle the temperature in the energy harvester. The device has been modeled using a finite element multi-physics based method, where the effect of the structure material properties and system parameters on the frequency and magnitude of temperature cycling, and the efficiency of energy recycling using the proposed structure, have been modeled. Results show that thermal contact conductance and heat source temperature differences play key roles in dominating the cantilever resonant frequency and efficiency of the energy conversion technique. This paper outlines the modeling, fabrication and testing of cantilever and pyroelectric structures and single element devices that demonstrate the potential of this technology for the development of high efficiency thermal-toelectrical energy conversion devices.

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

2012-06-01

384

Chemical reaction versus vibrational quenching in low energy collisions of vibrationally excited OH with O  

NASA Astrophysics Data System (ADS)

Quantum scattering calculations are reported for state-to-state vibrational relaxation and reactive scattering in O + OH(v = 2 - 3, j = 0) collisions on the electronically adiabatic ground state 2A'' potential energy surface of the HO2 molecule. The time-independent Schrödinger equation in hyperspherical coordinates is solved to determine energy dependent probabilities and cross sections over collision energies ranging from ultracold to 0.35 eV and for total angular momentum quantum number J = 0. A J-shifting approximation is then used to compute initial state selected reactive rate coefficients in the temperature range T = 1 - 400 K. Results are found to be in reasonable agreement with available quasiclassical trajectory calculations. Results indicate that rate coefficients for O2 formation increase with increasing the OH vibrational level except at low and ultralow temperatures where OH(v = 0) exhibits a slightly different trend. It is found that vibrational relaxation of OH in v = 2 and v = 3 vibrational levels is dominated by a multi-quantum process.

Pradhan, G. B.; Juanes-Marcos, J. C.; Balakrishnan, N.; Kendrick, Brian K.

2013-11-01

385

Energy transfer of highly vibrationally excited naphthalene. I. Translational collision energy dependence  

Microsoft Academic Search

Energy transfer between highly vibrationally excited naphthalene and Kr atom in a series of translational collision energies (108–847 cm?1) was studied separately using a crossed-beam apparatus along with time-sliced velocity map ion imaging techniques. Highly vibrationally excited naphthalene in the triplet state (vibrational energy: 16 194 cm?1; electronic energy: 21 400 cm?1) was formed via the rapid intersystem crossing of

Chen-Lin Liu; Hsu Chen Hsu; Yuan Chin Hsu; Chi-Kung Ni

2007-01-01

386

Energy transfer of highly vibrationally excited naphthalene. I. Translational collision energy dependence  

Microsoft Academic Search

Energy transfer between highly vibrationally excited naphthalene and Kr atom in a series of translational collision energies (108-847 cm-1) was studied separately using a crossed-beam apparatus along with time-sliced velocity map ion imaging techniques. Highly vibrationally excited naphthalene in the triplet state (vibrational energy: 16 194 cm-1 electronic energy: 21 400 cm-1) was formed via the rapid intersystem crossing of

Chen-Lin Liu; Hsu Chen Hsu; Yuan Chin Hsu; Chi-Kung Ni

2007-01-01

387

Coupled electro-mechanical response of an electroactive polymer cantilever structure and its application in energy harvesting  

NASA Astrophysics Data System (ADS)

Ionic polymer-metal composites (IPMC), piezoelectric polymer composites and nematic elastomer composites are materials, which exhibit characteristics of both sensors and actuators. Large deformation and curvature are observed in these systems when electric potential is applied. Effects of geometric non-linearity due to the chargeinduced motion in these materials are poorly understood. In this paper, a coupled model for understanding the behavior of an ionic polymer beam undergoing large deformation and large curvature is presented. Maxwell's equations and charge transport equations are considered which couple the distribution of the ion concentration and the pressure gradient along length of a cantilever beam with interdigital electrodes. A nonlinear constitutive model is derived accounting for the visco-elasto-plastic behavior of these polymers and based on the hypothesis that the presence of electrical charge stretches/contracts bonds, which give rise to electrical field dependent softening/hardening. Polymer chain orientation in statistical sense plays a role on such softening or hardening. Elementary beam kinematics with large curvature is considered. A model for understanding the deformation due to electrostatic repulsion between asymmetrical charge distributions across the cross-sections is presented. Experimental evidence that Silver(Ag) nanoparticle coated IPMCs can be used for energy harvesting is reported. An IPMC strip is vibrated in different environments and the electric power against a resistive load is measured. The electrical power generated was observed to vary with the environment with maximum power being generated when the strip is in wet state. IPMC based energy harvesting systems have potential applications in tidal wave energy harvesting, residual environmental energy harvesting to power MEMS and NEMS devices.

Ahish, B.; Anand, S. V.; Bharath, P.; Arvind, K.; Chakraborty, N.; Mahapatra, D. Roy

2009-03-01

388

Quantum control of energy flow in light harvesting.  

PubMed

Coherent light sources have been widely used in control schemes that exploit quantum interference effects to direct the outcome of photochemical processes. The adaptive shaping of laser pulses is a particularly powerful tool in this context: experimental output as feedback in an iterative learning loop refines the applied laser field to render it best suited to constraints set by the experimenter. This approach has been experimentally implemented to control a variety of processes, but the extent to which coherent excitation can also be used to direct the dynamics of complex molecular systems in a condensed-phase environment remains unclear. Here we report feedback-optimized coherent control over the energy-flow pathways in the light-harvesting antenna complex LH2 from Rhodopseudomonas acidophila, a photosynthetic purple bacterium. We show that phases imprinted by the light field mediate the branching ratio of energy transfer between intra- and intermolecular channels in the complex's donor acceptor system. This result illustrates that molecular complexity need not prevent coherent control, which can thus be extended to probe and affect biological functions. PMID:12037563

Herek, Jennifer L; Wohlleben, Wendel; Cogdell, Richard J; Zeidler, Dirk; Motzkus, Marcus

2002-05-30

389

From boots to buoys: promises and challenges of dielectric elastomer energy harvesting  

NASA Astrophysics Data System (ADS)

Dielectric elastomers offer the promise of energy harvesting with few moving parts. Power can be produced simply by stretching and contracting a relatively low-cost rubbery material. This simplicity, combined with demonstrated high energy density and high efficiency, suggests that dielectric elastomers are promising for a wide range of energy harvesting applications. Indeed, dielectric elastomers have been demonstrated to harvest energy from human walking, ocean waves, flowing water, blowing wind, and pushing buttons. While the technology is promising, there are challenges that must be addressed if dielectric elastomers are to be a successful and economically viable energy harvesting technology. These challenges include developing materials and packaging that sustains long lifetime over a range of environmental conditions, design of the devices that stretch the elastomer material, as well as system issues such as practical and efficient energy harvesting circuits. Progress has been made in many of these areas. We have demonstrated energy harvesting transducers that have operated over 5 million cycles. We have also shown the ability of dielectric elastomer material to survive for months underwater while undergoing voltage cycling. We have shown circuits capable of 78% energy harvesting efficiency. While the possibility of long lifetime has been demonstrated at the watt level, reliably scaling up to the power levels required for providing renewable energy to the power grid or for local use will likely require further development from the material through to the systems level.

Kornbluh, Roy D.; Pelrine, Ron; Prahlad, Harsha; Wong-Foy, Annjoe; McCoy, Brian; Kim, Susan; Eckerle, Joseph; Low, Tom

2011-04-01

390

Optimal Power Control for Energy Harvesting Transmitters in an Interference Channel  

E-print Network

harvesting wireless net- works are fundamentally different than their traditional coun- terparts due neutrality [1] was utilized in queueing-theoretic work [2], [3] to stabilize energy queues of energy

Yener, Aylin

391

A batteryless thermoelectric energy-harvesting interface circuit with 35mV startup voltage  

E-print Network

A batteryless thermoelectric energy-harvesting interface circuit to extract electrical energy from human body heat is implemented in a 0.35 ?m [mu m] CMOS process. A mechanically assisted startup circuit enables operation ...

Ramadass, Yogesh Kumar

392

Case-encapsulated triboelectric nanogenerator for harvesting energy from reciprocating sliding motion.  

PubMed

Reciprocating motion is a widely existing form of mechanical motion in natural environment. In this work we reported a case-encapsulated triboelectric nanogenerator (cTENG) based on sliding electrification to convert reciprocating motion into electric energy. Patterned with multiple sets of grating electrodes and lubricated with polytetrafluoroethylene (PTFE) nanoparticles, the cTENG exported an average effective output power of 12.2 mW over 140 k? external load at a sliding velocity of 1 m/s, in corresponding to a power density of 1.36 W/m(2). The sliding motion can be induced by direct-applied forces as well as inertia forces, enabling the applicability of the cTENG in addressing ambient vibration motions that feature large amplitude and low frequency. The cTENG was demonstrated to effectively harvest energy from human body motions and wavy water surface, indicating promising prospects of the cTENG in applications such as portable and stand-alone self-powered electronics. PMID:24601567

Jing, Qingshen; Zhu, Guang; Bai, Peng; Xie, Yannan; Chen, Jun; Han, Ray P S; Wang, Zhong Lin

2014-04-22

393

Nanotechnologies for efficient solar and wind energy harvesting and storage  

NASA Astrophysics Data System (ADS)

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 of nanoscale p-n junction networks creates n-type networks that act as preferential electron pathways, and p-type networks that act as preferential hole pathways, allowing positive and negative charges to travel to the contacts in physically separated paths, reducing charge recombination. We also describe PV nanotechnologies used to enhance light trapping, photon absorption, charge generation, charge transport, and current collection. Furthermore, we describe nanotechnologies used to improve the efficiency of power-generating wind turbines. These technologies include nanoparticle-containing lubricants that reduce the friction generated from the rotation of the turbines, nanocoatings for de-icing and self-cleaning technologies, and advanced nanocomposites that provide lighter and stronger wind blades. Finally, we describe nanotechnologies used in advanced secondary batteries and ultracapacitors. Nanostructured powder-based and carbon-nanotube-based cathodes and anodes with ultra-high surface areas boost the energy and power densities in secondary batteries, including lithium-ion and sodium-sulfur batteries. Nanostructured carbon materials are also controlled on a molecular level to offer large surface areas for the electrodes of ultracapacitors, allowing to store and supply large bursts of energy needed in some applications.

Eldada, Louay A.

2010-08-01

394

Low Head, Vortex Induced Vibrations River Energy Converter  

SciTech Connect

Vortex Induced Vibrations Aquatic Clean Energy (VIVACE) is a novel, demonstrated approach to extracting energy from water currents. This invention is based on a phenomenon called Vortex Induced Vibrations (VIV), which was first observed by Leonardo da Vinci in 1504AD. He called it ‘Aeolian Tones.’ For decades, engineers have attempted to prevent this type of vibration from damaging structures, such as offshore platforms, nuclear fuel rods, cables, buildings, and bridges. The underlying concept of the VIVACE Converter is the following: Strengthen rather than spoil vortex shedding; enhance rather than suppress VIV; harness rather than mitigate VIV energy. By maximizing and utilizing this unique phenomenon, VIVACE takes this “problem” and successfully transforms it into a valuable resource for mankind.

Bernitsas, Michael B.; Dritz, Tad

2006-06-30

395

Underwater energy harvesting from a turbine hosting ionic polymer metal composites  

NASA Astrophysics Data System (ADS)

In this study, we explore the possibility of energy harvesting from fluid flow through a turbine hosting ionic polymer metal composites (IPMCs). Specifically, IPMC harvesters are embedded in the blades of a small-scale vertical axis water turbine to convert flow kinetics into electrical power via low-frequency flow-induced IPMC deformations. An in-house fabricated Savonius-Darrieus hybrid active turbine with three IPMCs is tested in a laboratory water tunnel to estimate the energy harvesting capabilities of the device as a function of the shunting electrical load. The turbine is shown to harvest a few nanowatt from a mean flow of 0.43\\;m\\;{{s}^{-1}} for shunting resistances in the range 100-1000\\;\\Omega . To establish a first understanding of the energy harvesting device, we propose a quasi-static hydroelastic model for the bending of the IPMCs and we utilize a black-box model to study their electromechanical response.

Cellini, Filippo; Pounds, Jason; Peterson, Sean D.; Porfiri, Maurizio

2014-08-01

396

Energy transfer in nanowire solar cells with photon-harvesting shells C. H. Peters,a  

E-print Network

, to date, groups that have produced arrays of vertically ori- ented radial SiNW solar cells have achievedEnergy transfer in nanowire solar cells with photon-harvesting shells C. H. Peters,a A. R. Guichard; published online 23 June 2009 The concept of a nanowire solar cell with photon-harvesting shells

McGehee, Michael

397

Remote area wind energy harvesting for low-power autonomous sensors Abstract--A growing demand for deployment of autonomous  

E-print Network

Remote area wind energy harvesting for low-power autonomous sensors Abstract--A growing demand wind energy harvesting is presented, with a focus on an anemometer-based solution. By utilizing for localized, independent energy harvesting capabilities for each node. In this paper, a method of remote area

398

Improving Pyroelectric Energy Harvesting Using a Sandblast Etching Technique  

PubMed Central

Large amounts of low-grade heat are emitted by various industries and exhausted into the environment. This heat energy can be used as a free source for pyroelectric power generation. A three-dimensional pattern helps to improve the temperature variation rates in pyroelectric elements by means of lateral temperature gradients induced on the sidewalls of the responsive elements. A novel method using sandblast etching is successfully applied in fabricating the complex pattern of a vortex-like electrode. Both experiment and simulation show that the proposed design of the vortex-like electrode improved the electrical output of the pyroelectric cells and enhanced the efficiency of pyroelectric harvesting converters. A three-dimensional finite element model is generated by commercial software for solving the transient temperature fields and exploring the temperature variation rate in the PZT pyroelectric cells with various designs. The vortex-like type has a larger temperature variation rate than the fully covered type, by about 53.9%.The measured electrical output of the vortex-like electrode exhibits an obvious increase in the generated charge and the measured current, as compared to the fully covered electrode, by of about 47.1% and 53.1%, respectively. PMID:24025557

Hsiao, Chun-Ching; Siao, An-Shen

2013-01-01

399

Innovative microbial fuel cell for energy harvesting and corrosion protection  

NASA Astrophysics Data System (ADS)

Microbial Fuel cells (MFCs) are batteries driven by bacteria. MFCs have the potential of powering small sensors in remote areas and disposing organic waste safely by harvesting the energy stored in the waste products. From previous research in this field, a few important factors for MFC performance have been identified. These include the internal resistance of MFC, the surface area of anode with catalyst for the biofilm development, the type and number of bacteria, and the abundance of nutritional supplies to the bacteria. This paper describes the design of a novel single chamber MFC (SMFC) with carbon electrodes. Experiments were conducted to establish the relationship between each parameter and the power production. It is shown here that this SCMFC can generate electrical current without the use of PEM membranes or additives; the maximum voltage of around 411 mV can be achieved at the room temperature. These results also measured a various parameters such as pH, dissolved oxygen and solution conductivity during the operation of SMFC. Finally, experiment was conducted to evaluate an innovative concept of using MFC for corrosion protection.

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

2011-06-01

400

Energy Harvesting Characteristics from Water Flow by Piezoelectric Energy Harvester Device Using Cr/Nb Doped Pb(Zr,Ti)O3 Bimorph Cantilever  

NASA Astrophysics Data System (ADS)

A water flow energy harvester, which can convert water flow energy to electric energy, was fabricated for its application to rivers. This harvester can generate power from the bending and releasing motion of piezoelectric bimorph cantilevers. A Pb(Zr0.54Ti0.46)O3 + 0.2 wt % Cr2O3 + 1.0 wt % Nb2O5 (PZT-CN) thick film and a 250-µm-thick stainless steel were used as a bimorph cantilever. The electrical impedance matching was achieved across a resistive load of 1 k?. Four bimorph cantilevers can generate power from 5 to 105 rpm. The output powers were steadily increased by increasing the rpm. The maximum output power was 68 mW by 105 rpm. It was found that the water flow energy harvester can generate 58 mW by a flow velocity of (2 m/s) from the stream with the four bimorph cantilevers.

Kim, Kyoung-Bum; Kim, Chang Il; Jeong, Young Hun; Cho, Jeong-Ho; Paik, Jong-Hoo; Nahm, Sahn; Lim, Jong Bong; Seong, Tae-Hyeon

2013-10-01

401

Accurate Modeling and Prediction of Energy Availability in Energy Harvesting Real-Time Embedded Systems  

E-print Network

management problems of low power design for real-time embedded systems are usually solved at the system level, most real-time embedded systems are mobile and powered by batteries. Therefore, low power research harvesting is a promising technology for overcoming the energy limitations of battery-powered systems and has

Qiu, Qinru

402

Optimal Power Policy for Energy Harvesting Transmitters with Inefficient Energy Storage  

E-print Network

efficiency goes to unity. Based on the optimal offline policy, an online policy based on constant charging and discharging thresholds is proposed. The performance of the optimal offline and proposed online algorithms with energy harvesting nodes has been the focus of green communication research in the past few years

Yener, Aylin

403

Energy harvesting from self-sustained aeroelastic limit cycle oscillations of rectangular wings  

NASA Astrophysics Data System (ADS)

Three different aspect-ratio rectangular wings are designed and experimentally tested to produce self-sustained aeroelastic oscillations for energy harvesting via implementing a piezoelectric generator. Sensitivity measurements are conducted first to determine the critical conditions producing such oscillations with a dominant frequency of 1 Hz. Furthermore, the energy harvesting performance is maximized as the piezoelectric generator is implemented in parallel with oncoming flow streamline. Approximately 55 mW electricity is produced from a wing with a surface area of 0.025 m2. Unlike conventional wind turbine technology, the present work opens up another possible way to harvest energy via nonlinear aeroelastic oscillations.

Zhao, Dan; Ega, Evan

2014-09-01

404

Optimal transmission policies over vector Gaussian broadcast channels with energy harvesting transmitters  

Microsoft Academic Search

We consider an energy harvesting transmitter sending messages to two users over a vector broadcast channel. Energy required for communication arrives (is harvested) at the transmitter and a finite-capacity battery stores it before being consumed for transmission. Under off-line knowledge of energy arrivals, we obtain the trade-off between the performances of the users by characterizing the maximum departure region in

Omur Ozel; Jing Yang; Sennur Ulukus

2011-01-01

405

Combining dissimilar materials at nanometer scale for energy harvesting  

NASA Astrophysics Data System (ADS)

The development of next-generation energy resources that are reliable and economically/environmentally acceptable is a key to harnessing and providing the resources essential for the life of mankind. Our research focuses on the development of novel semiconductor platforms that would significantly benefit energy harvesting, in particular, from light and heat. In these critical applications, traditional semiconductor solid-state devices, such as photovoltaic (PV) and thermoelectric (TE) devices based on a stack of single-crystal semiconductor thin films or single-crystal bulk semiconductor have several drawbacks, for instance; scalability-limits arise when ultra-large-scale implementation is envisioned for PV devices and performance-limits arise for TE devices in which the interplay of both electronic and phonon systems is important. In our research, various types of nanometer-scale semiconductor structures (e.g., nanowires and nanoparticles) coupled to or embedded within a micrometer-scale semiconductor structure (i.e., semiconductor nanomicrometer hybrid platforms) are explored to build a variety of non-conventional PV and TE devices. Two core projects are to develop semiconductor nano-micrometer hybrid platforms based on (1) an ensemble of single-crystal semiconductor nanowires connected to non-single-crystal semiconductor surfaces and (2) semimetallic nanoparticles embedded within a single-crystal semiconductor. The semiconductor nano-micrometer hybrid platforms are studied within the context of their basic electronic, optical, and thermal properties, which will be further assessed and validated by comparison with theoretical approaches to draw comprehensive pictures of physicochemical properties of these semiconductor platforms.

Kobayashi, Nobuhiko P.

2010-04-01

406

Fluoroethylenepropylene ferroelectret films with cross-tunnel structure for piezoelectric transducers and micro energy harvesters  

NASA Astrophysics Data System (ADS)

Layered fluoroethylenepropylene (FEP) ferroelectret films with cross-tunnel structure were fabricated from sheets of FEP films by template-patterning followed by a fusion-bonding process and contact charging. The typical piezoelectric d33 coefficients, measured by a quasi-static method of samples not annealed, are in the range of 1000-3700 pC/N. The resonance behavior of the samples is analyzed by dielectric spectroscopy which also yields Young's modulus. Microphones built with such films exhibit a somewhat decreasing frequency response up to 1 kHz, an increase of the responses due to diffraction effects at higher frequencies, and eventually a peak probably due to a thickness resonance at about 40 kHz. Annealing at 125 °C indicates that the sensitivity stabilizes at about 40% of the original value. From this data, stable dynamic d33 coefficients of up to 300 pC/N can be calculated. A micro energy harvesting generator utilizing these films and based on the excitation of thickness vibrations is also described. With an active area of 4.3 cm2 and a seismic mass of 69.5 g, power up to 0.5 ?W referred to an acceleration of 1 g can be generated at a frequency of 120 Hz.

Zhang, Xiaoqing; Sessler, Gerhard M.; Wang, Yujie

2014-08-01

407

Increased piezoelectric energy harvesting from human footstep motion by using an amplification mechanism  

NASA Astrophysics Data System (ADS)

In this paper, we propose a piezoelectric energy harvester to scavenge the impact energy from human footsteps at low input frequencies. The device consists of an amplification mechanism and piezoelectric bimorphs. When a human foot strikes the proposed harvester, the amplification mechanism deforms the piezoelectric bimorphs in the 31-mode to produce a large mechanical strain, meaning that the output power can be generated with high efficiency. A maximum output power of 27.5 mW was generated by the proposed harvester at an input frequency of 1.5 Hz (representing fast walking), while 18.6 mW was generated at 1.0 Hz (representing slow walking). Comparison experiments also showed that the proposed harvester can produce much a higher output power than that the same harvester operating in the 33-mode under the same working conditions.

Xie, Longhan; Cai, Mingjing

2014-10-01

408

Minimization of the vibration energy of thin-plate structures and the application to the reduction of gearbox vibration  

NASA Technical Reports Server (NTRS)

While the vibration analysis of gear systems has been developed, a systematic approach to the reduction of gearbox vibration has been lacking. The technique of reducing vibration by shifting natural frequencies is proposed here for gearboxes and other thin-plate structures using the theories of finite elements, modal analysis, and optimization. A triangular shell element with 18 degrees of freedom is developed for structural and dynamic analysis. To optimize, the overall vibration energy is adopted as the objective function to be minimized at the excitation frequency by varying the design variable (element thickness) under the constraint of overall constant weight. Modal analysis is used to determine the sensitivity of the vibration energy as a function of the eigenvalues and eigenvectors. The optimum design is found by the gradient projection method and a unidimensional search procedure. By applying the computer code to design problems for beams and plates, it was verified that the proposed method is effective in reducing vibration energy. The computer code is also applied to redesign the NASA Lewis gear noise rig test gearbox housing. As one example, only the shape of the top plate is varied, and the vibration energy levels of all the surfaces are reduced, yielding an overall reduction of 1/5 compared to the initial design. As a second example, the shapes of the top and two side plates are varied to yield an overall reduction in vibration energy of 1/30.

Inoue, Katsumi; Krantz, Timothy L.

1995-01-01

409

Minimization of the Vibration Energy of Thin-Plate Structures and the Application to the Reduction of Gearbox Vibration  

NASA Technical Reports Server (NTRS)

While the vibration analysis of gear systems has been developed, a systematic approach to the reduction of gearbox vibration has been lacking. The technique of reducing vibration by shifting natural frequencies is proposed here for gearboxes and other thin-plate structures using the theories of finite elements, modal analysis, and optimization. A triangular shell element with 18 degrees of freedom is developed for structural and dynamic analysis. To optimize, the overall vibration energy is adopted as the objective function to be minimized at the excitation frequency by varying the design variable (element thickness) under the constraint of overall constant weight. Modal analysis is used to determine the sensitivity of the vibration energy as a function of the eigenvalues and eigenvectors. The optimum design is found by the gradient projection method and a unidimensional search procedure. By applying the computer code to design problems for beams and plates, it was verified that the proposed method is effective in reducing vibration energy. The computer code is also applied to redesign the NASA Lewis gear noise rig test gearbox housing. As one example, only the shape of the top plate is varied, and the vibration energy levels of all the surfaces are reduced, yielding an overall reduction of 1/5 compared to the initial design. As a second example, the shapes of the top and two side plates are varied to yield an overall reduction in vibration energy of 1/30.

Inoue, Katsumi; Krantz, Timothy L.

1995-01-01

410

Comparison of vibrational conductivity and radiative energy transfer methods  

E-print Network

of the wideband response of built-up stuctures subjected to high frequency vibrational excitation. The first], plates [7, 8] and built-up structures [9]. In the field of acoustics, the so-called radiosity method [10 of the repartition of energy in built-up structures. Both methods are also based on analogies with some equations

Paris-Sud XI, Université de

411

Experimental Vibrational Zero-Point Energies: Diatomic Molecules  

Microsoft Academic Search

Vibrational zero-point energies (ZPEs), as determined from published spectroscopic constants, are derived for 85 diatomic molecules. Standard uncertainties are also provided, including estimated contributions from bias as well as the statistical uncertainties propagated from those reported in the spectroscopy literature. This compilation will be helpful for validating theoretical procedures for predicting ZPEs, which is a necessary step in the ab

Karl K. Irikura

2007-01-01

412

Excitonic energy transfer in light-harvesting complexes in purple bacteria  

E-print Network

Two distinct approaches, the Frenkel-Dirac time-dependent variation and the Haken-Strobl model, are adopted to study energy transfer dynamics in single-ring and double-ring light-harvesting (LH) systems in purple bacteria. ...

Ye, Jun

413

A multi-cell piezoelectric device for tunable resonance actuation and energy harvesting  

E-print Network

Variable stiffness actuation and energy harvesting have been important yet separate challenges in robotics. Both functions are needed, however, for mobile robots on extended missions when actuators and generators must be ...

Secord, Thomas W.

414

Power and efficiency analysis of a flapping wing wind energy harvester  

NASA Astrophysics Data System (ADS)

Energy harvesting from flowing fluids using flapping wings and fluttering aeroelastic structures has recently gained significant research attention as a possible alternative to traditional rotary turbines, especially at and below the centimeter scale. One promising approach uses an aeroelastic flutter instability to drive limit cycle oscillations of a flexible piezoelectric energy harvesting structure. Such a system is well suited to miniaturization and could be used to create self-powered wireless sensors wherever ambient flows are available. In this paper, we examine modeling of the aerodynamic forces, power extraction, and efficiency of such a flapping wing energy harvester at a low Reynolds number on the order of 1000. Two modeling approaches are considered, a quasi-steady method generalized from existing models of insect flight and a modified model that includes terms to account to the effects of dynamic stall. The modified model is shown to provide better agreement with CFD simulations of a flapping energy harvester.

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

2012-04-01

415

DEVELOPMENT OF A PIEZOELECTRIC BASED ENERGY HARVESTING SYSTEM FOR AUTONOMOUS WIRELESS SENSOR NODES  

E-print Network

DEVELOPMENT OF A PIEZOELECTRIC BASED ENERGY HARVESTING SYSTEM FOR AUTONOMOUS WIRELESS SENSOR NODES, autonomous systems, Structural Health Monitoring. INTRODUCTION The development of Smart Wireless Sensors and miniaturization of the entire system. This miniaturization makes the integrated topologies a suitable option

Paris-Sud XI, Université de

416

IRON-INDUCED CHANGES IN LIGHT HARVESTING AND PHOTOCHEMICAL ENERGY CONVERSION IN EUKARYOTIC MARINE ALGAE  

EPA Science Inventory

The role of iron in regulating light harvesting and photochemical energy conversion process was examined in the marine unicellular chlorophyte Dunaliella tertiolecta and the marine diatom Phaeodactylum tricornutum. In both species, iron limitation led to a reduction in cellular c...

417

Asynchronous phase shifted electromagnetic energy harvester Jinkyoo Parka, Soonduck Kwonb and Kincho H. Lawa  

E-print Network

. Unlike conventional, large-scale renewable energy generating systems such as wind turbines, thermal harvester, the need for regularly changing batteries can be eliminated, which in turn can reduce maintenance

Stanford University

418

Piezoelectric Artificial Kelp: Experimentally Validated Parameter Optimization of a Quasi-Static, Flow-Driven Energy Harvester  

E-print Network

application with defined input and design constraints must first be chosen. The following thesis established a concept design of a hydrokinetic energy harvesting system, the piezoelectric artificial kelp (PAK), which uses piezoelectric materials to harvest...

Pankonien, Alexander Morgan

2011-10-21

419

Skyrmion vibrational energies with a generalized mass term  

E-print Network

We study various properties of a one parameter mass term for the Skyrme model, originating from the works of Kopeliovich, Piette and Zakrzewski, through the use of axially symmetric solutions obtained numerically by simulated-annealing. These solutions allow us to observe asymptotic behaviors of the B=2 binding energies that differ to those previously obtained. We also decipher the characteristics of three distinct vibrational modes that appear as eigenstates of the vibrational Hamiltonian. This analysis further examine the assertion that the one parameter mass term offers a better account of baryonic matter than the traditional mass term.

Merlin C. Davies; Luc Marleau

2009-04-21

420