toward small-scale wind energy harvesting: design,...

Review ArticleToward Small-Scale Wind Energy Harvesting DesignEnhancement Performance Comparison and Applicability

Liya Zhao and Yaowen Yang

Nanyang Technological University 50 Nanyang Avenue Singapore 639798

Correspondence should be addressed to Yaowen Yang cywyangntuedusg

Received 8 September 2016 Accepted 15 December 2016 Published 21 March 2017

Academic Editor Mickael Lallart

Copyright copy 2017 Liya Zhao and Yaowen YangThis is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

The concept of harvesting ambient energy as an alternative power supply for electronic systems like remote sensors to avoidreplacement of depleted batteries has been enthusiastically investigated over the past few years Wind energy is a potential powersource which is ubiquitous in both indoor and outdoor environments The increasing research interests have resulted in numeroustechniques on small-scale wind energy harvesting and a rigorous and quantitative comparison is necessary to provide the academiccommunity a guidelineThis paper reviews the recent advances on various wind power harvesting techniques ranging between cm-scaled wind turbines and windmills harvesters based on aeroelasticities and those based on turbulence and other types of workingprinciples mainly from a quantitative perspectiveThemerits weaknesses and applicability of different prototypes are discussed indetail Also efficiency enhancing methods are summarized from two aspects that is structural modification aspect and interfacecircuit improvement aspect Studies on integrating wind energy harvesters with wireless sensors for potential practical uses are alsoreviewed The purpose of this paper is to provide useful guidance to researchers from various disciplines interested in small-scalewind energy harvesting and help them build a quantitative understanding of this technique

1 Introduction

Studies on harvesting power from ambient energy sourceshave flourished in the past few years with an ultimateobjective to remove the reliance of low-power electronicdevices on electrochemical batteries as well as the associ-ated requirement of periodic replacement and maintenanceVarious energy sources are available surrounding the elec-tronic system like solar wind thermal energy mechanicalvibration and human activities Among them wind energyis ubiquitous and exists almost everywhere in our dailylife such as the flow in indoor heating and ventilation airconditioning systems and natural wind in outdoor spaces Itcan serve as an alternative power supply to implement self-powered electronic systems like self-powered wireless sensornetworks (WSNs) When a specific structure is subjected towind flows limit cycle oscillations will occur due to the fluid-structure interactionThe vibration strain energy can be ben-eficially transferred into electricity using various conversionmechanisms such as electrostatic [1 2] electromagnetic [3]

and piezoelectric conversions Piezoelectric conversion hasattracted rapidly growing interests due to the high powerdensity and ease of integration with microsystems [1 4ndash13]

Recently the field of small-scale wind energy harvestinghas experienced dramatic growth [14ndash21] Researchers havereported studies on harnessing wind power using minia-turized windmills (eg [22]) or making use of aeroelasticinstabilities such as vortex-induced vibration (VIV) (eg[23]) galloping (eg [24 25]) aeroelastic flutter (eg [26])andwake galloping (eg [27]) Turbulence-induced vibrationhas also been utilized for wind power extraction (eg [28])Numerous techniques have emerged due to the growingresearch enthusiasm therefore a rigorous and quantitativecomparison and review are necessary to provide the academiccommunity a guideline This paper focuses on a com-prehensive comparison of various small-scale wind energyharvesting techniques including cm-scaled wind turbinesand windmills and harvesters based on aeroelasticities andturbulences as well as other types of working principles Incontrast to prior surveys [20 21 29ndash31] the emphasis of

HindawiShock and VibrationVolume 2017 Article ID 3585972 31 pageshttpsdoiorg10115520173585972

2 Shock and Vibration

this paper is laid on the quantitative comparison betweenthe various fabricated prototypes in the literature regardingtheir dimensions cut-in wind speeds cut-out wind speedspeak power values as well as power densities and so forthbased on which merits weaknesses and applicability ofdifferent designs are discussed in detail The main findingsare summarized in Tables 1-2 and 4ndash8 Moreover besidesthe technique comparison enhancing methods of powerextraction efficiency are reviewed and discussed from twoaspects that is structural modification aspect and interfacecircuit improvement aspect In addition review is conductedon studies about integrating wind energy harvesters withwireless sensors for practical engineering applications Thispaper aims to help researchers from various disciplinesgain quantitative understanding of small-scale wind energyharvesting techniques and provide useful guidance to thosewho want to develop and improve the efficiency of a windenergy harvester

2 Designs of Aeroelastic PiezoelectricEnergy Harvesters

Many designs of small-scale wind energy harvesters havebeen reported in the literature including those in the formof small-scale windmills and turbines and those based onthe aeroelastic instabilities like VIV galloping flutter wake-induced oscillation and TIV In this section performances ofthe recent small-scale wind energy harvester designs will bereviewed and compared

21 Small-Scale Windmill and Wind Turbine Rancourt etal [35] investigated the performance of power generationof a centimeter-scale windmill Power was generated usingelectromagnetic transduction mechanism Three prototypesof propellers were tested in the wind tunnel which wereall 42 cm in diameter with four blades of different pitchangels The experimental results showed that the ldquoSchmitztheoryrdquo which was developed for large scale wind turbine todetermine the optimal tip speed ratio for maximum turbineefficiency (ie kinetic power extracted from thewind over theavailable kinetic flow energy for the area covered by the diskof the propeller) was also valid for small-scale wind turbinesHowever the power generation efficiency (electrical poweroutput over the available kinetic flow energy for the area cov-ered by the disk of the propeller) at low wind speed decreasedsharply due to the friction in the generator and the internalelectric resistance At a high wind speed of 118ms a largepower of 130mW was achieved corresponding to a powergeneration efficiency of 95 while a lower power of 24mWwas obtained at 55ms with a decreased efficiency of 185

Bansal et al [77] and Howey et al [36] tested a miniatureelectromagnetic wind turbine in cm-scale claimed to be thesmallest turbine-based energy harvester reported to datewith a rotor diameter of 2 cm and outer diameter of 32 cmThe turbine [36] consisted of two rotating magnetic ringsmounted on the rim of the rotor and fixed stator coil sand-wiched between themagnetic ringsWind tunnel experimentfound that the cut-in wind speed was 3ms below whichthe turbine could not operate The test was run up to 10ms

and a power of 80 120583W to 43mW was achieved Comparedto the device of Rancourt et al [35] at a low wind speedof 55ms similar power generation efficiency was obtainedthat is 135 for 5ms and 152 for 6ms It was noted thatat wind speeds lower than 7ms the generated power waslimited by bearing loss while at wind speeds higher than7ms power output was limited by resistive generator lossFuture designs of miniature turbines aimed to harvest energyfrom low speed flows should pay attention to these two issues

Both studies of Rancourt et al [35] and Howey et al [36]show that the major challenge of miniature electromagneticwindmill lies in the greatly decreased power generationefficiency in slow flows Of course if a more sophisticatedsmall-scale wind turbine can be established incorporatingoptimized shape of airfoil and proper design of diffuser theoutput power can be significantly increased [78 79] It wasreported by Kishore et al [79] that a properly designed small-scale wind energy portable turbine (SWEPT) with a diameterof 394 cm can generate a power-up to 830mW at a windspeed of 5ms Yet this size of the turbine is much larger thanthose of the small-scale harvesters mentioned above whichare mainly smaller than or in the order of 10 cm

Recently small-scale windmills using piezoelectric trans-duction have shown great potential in efficiently harvestinglow speed flow energy The rotation of the windmill shaftunder wind flows is transferred to oscillatory motion of thepiezoelectric transducer The mechanical transfer is some-times achieved by direct impact between the piezoelectriccantilever and the cam or blade with a working principlesimilar to that of amechanical stopper [80] some other timesit is achieved throughmagnetic interfactionwhere no contactimpact is required

Priya et al [22] proposed a piezoelectric windmill toharvest energy from low speed wind flows Twelve piezo-electric bimorphs were arranged in a circular array aroundthe circumference of the center shaft of the windmill Twelverubber stoppers were connected to the shaft each of whichwas in contact with one of the bimorphsThe shaft connectedvia a cam to a rotating fan was rotated via the camshaftmechanism When the shaft rotated the stoppers causedthe back and forth movements of the bimorph transducersgenerating electrical energy via direct piezoelectric effectThevoltage was measured across a 46 kΩ load at an oscillatoryfrequency of 42Hz Experimentally a standard circuit wasemployed and a power of 102mW after rectification wasobtained at 6Hz and 46 kΩ It was found that powerwas increased with the prestress level and the number ofbimorphs which yet also resulted in increased difficulty inthe fan rotation thus causing an increased cut-in wind speed

In a subsequent work Priya [37] presented a theoreticalmodel based on bending beam theory of bimorphs andequivalent circuit of capacitor to predict the output power ofthe above-mentioned piezoelectric windmill Ten bimorphswere used in the experiment A cut-in wind speed of 47mphand a cut-out wind speed of 12mph (above which damageof structure will occur) were measured A maximum powerof 75mW was obtained after rectification at 10mph across aload of 67 kΩ A linear relationship was given between thesaturated frequency (final constant operating frequency at a

Shock and Vibration 3

Table1Summaryof

vario

ussm

all-scalewindm

illsa

ndwindturbines

Author

Transductio

nMechanical

transfe

rCu

t-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perswept

area

(mWcm2)

Advantagesdisa

dvantages

Rancou

rtetal

[35]

Electro

magnetic

mdashmdash

mdash130

118

42c

min

dia

938

(i)Highpo

wer

generatio

neffi

ciency

athigh

windspeed

(ii)A

tlow

windspeedeffi

ciency

decreased

sharplydu

etothefric

tionin

theg

enerator

andtheinternalelectric

resistance

How

eyetal[36]

Electro

magnetic

mdash3

mdash43

1032c

min

dia

0535

(i)Be

aringlossandresistiv

egenerator

loss

limits

them

iniaturiz

ationof

theturbine

Priyae

tal[22]

Piezoelectric

Con

tactvia

mechanical

stopp

ermdash

mdash102

mdash12

bimorph

sinac

ircular

arrayeach

of6times2times

005

cm3

00902

(i)Proves

thefeasib

ilityof

efficiently

harvestin

glowspeedwindenergy

using

piezoelectric

materials

(ii)B

imorph

sare

notvibratin

gin

phases

otheo

utpu

thas

tobe

individu

allyprocessed

Priya[

37]

Piezoelectric

Con

tactvia

mechanical

stopp

er21

54

7545

10bimorph

sinac

ircular

arrayeach

of6times2times

006

cm3

006

63

Chen

etal[38]

Piezoelectric

Con

tactvia

mechanical

stopp

er21

62

1254

508times116times76

2cm3

00134

(i)Ea

syto

fabricate

(ii)S

pace

efficientw

ithar

ectang

ular-array

arrang

emento

ftransdu

cers

(iii)Com

binedcircuitcan

beused

because

allthe

bimorph

sare

vibratingin

phase

(iv)P

ower

was

muchlower

comparedto

thec

ircular

windm

ill

Myersetal[39]

Piezoelectric

Con

tactvia

mechanical

stopp

er24

mdash5

45

762times1016times1270c

m3

00388

(i)Ca

ptured

windenergy

isincreasedby

employingthreefan

blades

Bressersetal

[40]

Piezoelectric

Con

tact-le

ssvia

magnetic

interaction

09

mdash12

40

1651times

1651times

2286c

m3

318times10minus3

(i)Minim

izingthefric

tionallossb

yavoiding

directmechanicalcon

tact

(ii)P

rolong

ingthefatigue

lifeo

fpiezoelectric

elements

(iii)Lo

weringdo

wnthec

ut-in

windspeed

Karamietal[41]

Piezoelectric

Con

tact-le

ssvia

magnetic

interaction

2mdash

410

8times8times175c

m3

00286

(i)Intro

ducing

nonlinearityinto

the

harvester

(ii)U

tilizingbo

thno

nlinearp

aram

etric

excitatio

nandordinary

excitatio

nand

helpingto

achievelow

cut-inwindspeed

high

output

powerand

largeo

peratio

nal

rang

eofw

indspeed


Table2Summaryof

vario

usVIV

energy

harvesterd

evices1

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(lock-in

)(m

s)

Dim

ensio

nsPo

wer

density

per

volume(mWcm3)lowast1

Advantagesdisa

dvantagesa

ndother

inform

ation

AllenandSm

its[42]

(inwater)

Piezoelectric

Plate

005

(water

speed)

08(w

ater

speed)

mdashmdash

Bluff

bodyfrontal

dimensio

n505

cmamp

381cm

Eelm

embraneleng

th

457cm

amp76

cm

(i)Investigatedandconfi

rmed

the

feasibilityof

harvestin

gflu

idenergy

via

VIV

(ii)D

etermines

thatop

timalperfo

rmance

occursatresonancec

onditio

nTaylor

etal[43](in

water)

Piezoelectric

Plate

mdashmdash

3V(peak

voltage)

05(w

ater

speed)

PVDFeel24

cmtimes

76cmtimes150120583

m110(V

cm3)

Robb

inse

tal[44]

Piezoelectric

Cylin

der

mdashmdash

7867

Flapping

PVDF

mem

brane254cmtimes

1778

cmtimes4572120583m

0378

(i)Th

euse

ofwindw

ardbluff

body

and

masso

nthefreee

ndof

thefl

apping

piezoelementcan

enhancee

nergy

conversio

n(ii)E

xperim

entally

proves

theu

seof

quasi-reson

antrectifi

ercanincrease

the

efficiency

byafactoro

f23comparedto

asta

ndardfull-waver

ectifi

er

(iii)Th

eoreticallyconfi

rmsthe

useo

fAFC

MFC

canincrease

thee

fficiency

bya

factor

of25

comparedto

PVDF

Poberin

gand

Schw

esinger[45]

Piezoelectric

Polygon

45

450108

45

Bluff

body

frontal

dimensio

n10

35cm

Th

reeidentical

cantilevers14times118times

0035c

m3

00817

(i)Th

euse

ofpiezoelectric

bimorph

cantilevere

nsures

onlythefi

rstm

ode

deform

ationto

guaranteen

ocharge

cancellatio

non

thes

urface

(ii)Th

eoretic

allyprop

oses

theo

ptim

algeom

etry

of119871119863=2125

(iii)Ad

jacent

cantileversarrang

ement

enhances

output

power

Poberin

getal[46

]Piezoelectric

D-shape

15mdash

140

Bluff

body

frontal

dimensio

n10

35cm

Nineidentical

cantilevers(Series1)22

times118times0035c

m3

0164

(i)Ex

perim

entally

valid

ates

theo

ptim

algeom

etry

of119871119863=2125

(ii)U

seof

stapled

piezoelectric

layers

enhanceo

utpu

tpow

er

(iii)Ad

jacent

cantileversarrang

ementcan

furtherlow

erthec

ut-in

windspeeddo

wn

to8m

s

Akaydin

etal[47]

Akaydın

etal[48]

Piezoelectric

Cylin

der

mdashmdash

000

472

3

Bluff

body

3cm

india

12m

inleng

th

Cantilever3times16times

002

cm3

472times10minus6

(i)Th

edriv

ingmechanism

oftheb

eamrsquos

oscillatio

nwas

discovered

viaC

FDas

the

combinedeffecto

fthe

overpressure

resulting

from

thes

tagn

ationregion

and

thes

uctio

nof

thec

oreo

fano

ther

vortex

ontheo

pposite

side

(ii)Th

eoptim

alpo

sitionof

theu

pstre

amtip

ofthec

antilever

was

foun

dto

alon

gthe

centerlin

eand

atad

istance

of119909119863=2

(iii)Non

attachmento

fbluffbo

dyand

cantileverresultsin

very

lowou

tput

power


Table2Con

tinued

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(lock-in

)(m

s)

Dim

ensio

nsPo

wer

density

per


Advantagesdisa

dvantagesa

ndother

inform

ation

Akaydin

etal[23]

Piezoelectric

Cylin

der

mdashmdash

01

1192

Bluff

body

198c

min

dia

203cm

inleng

th


00635

cm3

147times10minus3

(i)Attachmento

fthe

cylin

dero

nthe

cantilevertip

anduseo

fPZT

inste

adof

PVDFgreatly

enhanced

theo

utpu

tpow

er

(ii)A

ttachmento

fthe

cylin

dero

nthe

cantilevertip

redu

cesthe

resonancew

ind

speedform

axim

umpo

wer

Weinstein

etal[49]

Piezoelectric

Cylin

der

25(55)

555

Bluff

body

25cm

india

11cm

inleng

th


025

cm3

Who

leplanes

ize225times

11cm2

00918

(i)Operatio

nalw

indspeedrang

eis

broadenedbecausethe

harvesters

resonancefrequ

ency

andits

resonance

windspeedcanbe

tunedby

adjusting

the

positionof

thea

dded

weight

(ii)T

uningmechanism

isno

tautom

atic

Gao

etal[50]

Piezoelectric

Cylin

der

31

mdash003

5(tu

rbulent

flowspeed)

Bluff

body

291cm

india

36c

min

leng

th

Cantilever31times

10times

00202

cm3

125times10minus3

(i)Tu

rbulentfl

owresults

inhigh

erou

tput

power

ofharvesterthanlaminar

flow

(ii)T

urbu

lencee

xcitatio

niscla

imed

tobe

thed

ominantd

rivingmechanism

ofthe

harvestervortex

shedding

excitatio

nin

the

lock-in

region

givesa

dd-oncontrib

ution

(iii)Ca

ntilevera

ndcylin

dera

rein

parallel

WangandKo

[51]

Piezoelectric

NA

mdashmdash

2times10minus4

mdashPV

DFfilm25times13times

00205

cm3

300times10minus3

(i)Ca

nbe

easilydeployed

inthep

ipelines

tirec

avitiesorm

achinery

byinsta

lling

adiaphragm

onthew

all

(ii)O

utpu

tpow

erisrelativ

elylow

comparedto

otherd

evices

(iii)Metho

dsof

enhancingpo

wer

are

prop

osedfor

exam

pleop

timizingthe

blockage

ratio

adjustin

gthed

iaph

ragm

position

andusingmaterialw

ithhigh

piezoelectric

constants

Wangetal[52]

Electro

magnetic

Trapezoidal

mdashmdash

177times10minus3

138(w

ater

speed)

Bluff

body

425m

mamp

1mm

inbases16

3mm

inheight

Magnet08times08times

1cm3

Coil2c

min

dia

02c

min

thickn

ess

133times10minus3

Tam

Nguyenetal

[53]

Piezoelectric

Triang

lemdash

mdash59times10minus7

207

Twoidentic

albluff

bodies0425

cmin

base

leng

th0218cm

inaltitud

ePV


00205

cm3

370times10minus6

1Ifmorethanon

esized

prototypes

wereinvestig

ated

inther

eferencethe

inform

ationof

dimensio

nandcriticalw

indspeeds

listedin

thetablecorrespo

ndstotheo

negiving

maxim

umou

tput

power

lowast1Th

edevicev

olum

eisa

pproximated

with

outcon

sideringthep

iezoelectricelem

entvolum

ethus

thep

ower

density

calculated

isthec

onservativee

stimates

show

ingtheu

pper

boun

d


constant wind speed) of the windmill and the wind speed asf (Hz) = minus093 + 129U which well captured the experimentalobservation that the frequency linearly increased with thewind speed Also it was found that the generated poweralmost linearly increased with the frequency It was suggestedthat the piezoelectric windmill could be a feasible powersupply for wireless sensors

Chen et al [38] investigated the performance of windenergy harvester with similar working principle to that ofthe above piezoelectric windmills but with a rectangulararrangement of piezoelectric transducers Twelve bimorphtransducers were arranged in six rows and two columnswith a gap of 6mm between each other A cylindrical rodin between the two columns was connected via a camshaftmechanism to a rotating fan which caused the up and downmovement of the rod Subsequently the six hooks on the rodinduced back and forth oscillations of the transducers fromwhich electrical energy could be generated The variationof power with wind speed from experiment was similar tothat of Priya [37] With a load of 17 kΩ a cut-in windspeed of 47mph and a cut-out wind speed of 14mph weremeasured with a maximum power of 12mW obtained at12mph Compared to the windmill this prototype is easyto fabricate and is space efficient with a rectangular-arrayarrangement of transducers also since all the bimorphs arevibrating in phase combined circuit can be used eliminatingthe trouble of using individual processing circuit required inthe circular windmill as summarized by Myers et al [39]Yet the power was much lower compared to the circularwindmill To solve this issue Myers et al [39] proposedan optimized rectangular piezoelectric windmill to enhancepower output by employing three fan blades to enlarge thecovered flow surface and to increase the captured windenergy The number of piezoelectric transducers was alsoincreased with two rows containing nine transducers in eachrow It was measured that with a small sized prototype of 3 times4 times 5 inch3 (762 times 1016 times 1270 cm3) an enhanced power ofthe order of 5mWwas obtained at 10mph It should be notedthat for all the above-mentioned piezoelectric windmills thesame piezoelectric transducers were used that is APC 855with dimensions of a single piece of 60 times 20 times 06mm3

For the above-mentioned impact-driven windmills achallenging issue exists that the frequent impacts not only dis-sipate some kinetic energy but also cause fatigue problems ofthe piezoelectric cantilevers and inducemechanical damagesIn order to overcome this shortcoming some researchershave proposed windmills that do not require direct impactsbut induce oscillations of the transducers through magneticinteractions

Bressers et al [40] proposed a design of piezoelectricwind turbine where the piezoelectric elements were ldquocontact-lessrdquo actuated through magnetic interaction A vertical axiswind turbine was connected to a disk to which a seriesof alternating polarity magnets were attached The magnetswere also attached at the tips of the cantilevered transducerswhich underwent harmonic oscillations through alternatingattractiverepulsive magnetic force when the blades wererotating in wind flow Measurement showed that with a two-blade and four-magnet rotor the cut-in wind speed was

lowered down to 2mph and a maximum power of around12mW was obtained at 9mph

Karami et al [41] proposed a nonlinear piezoelectric windturbine A vertical axis turbine was placed on top of fourvertical cantilevered piezoelectric transducers Two arrange-ments of tangential configuration (80 times 80 times 175mm3) andradial configuration (75 times 75 times 165mm3) were considered Inboth configurations four tip magnets were embedded at thetips of the transducers while five magnets were attached tothe bottom of the rotating disk that was fixed to the bladesDifferent from the device of Bressers et al [40] nonlinearitywas introduced to the transducers The rotation of the bladesinduced the distance between the disk and tip magnetsto continuously alter making the transducer alternatelyundergo bistable and monostable dynamics Therefore thetransducer was both directly and parametrically excited Forthe tangential configuration with a magnetic gap of 25mmand a load of 247 kΩ the cut-in wind speed was measuredto be 2ms and a maximum power of 4mW at 10mswas obtained while for the radial configuration the outputpower was one order of magnitude less than that from thetangential design It was explained that the direct excitationin the radial configuration was not as significant as that in thetangential configuration It was concluded that the nonlinearparametric excitation and ordinary excitation mechanismscan result in several advantages including the low cut-inwind speed high output power and large operational rangeof wind speed

Miniaturized windmills or wind turbines can generatea significant amount of power Yet the biggest concern isthat the rotary components are not desired for long-termuse of such small sized devices A summary of the variouswindmills and miniaturized turbines reviewed is presentedin Table 1 Their merits or limitations and other informationthat the authors feel useful are also given in the table Forthe present table and the following ones (Tables 2 and 4ndash8)power density per swept areavolume is calculated by dividingthe maximum output power by the frontal area normal to theflowdevice volume Because the volume of some accessorycomponents (eg the joints) and elements taking very smallproportions of the whole volume (eg a short piezoelectricsheet attached to a long substrate cantilever) are ignoredthe power density values should be considered the estimatedupper bound for comparison purpose only

22 Energy Harvesters Based on Vortex-Induced VibrationsThe concept of using VIV to harvest energy was first inves-tigated in flowing water instead of wind Allen and Smits[42] proposed an ldquoenergy harvesting eelrdquo to harvest flowingwater energy The unit consisted of a fixed flat plate as abluff body with a piezoelectric membrane placed in the wakeThe membrane was set free in the downstream Alternatingvortices were shedded on either side of the bluff bodyresulting in pressure differential thus forcing the membraneto oscillate with a movement similar to that of a natural eelswimming Particle image velocimetry (PIV) experiment wasconducted to investigate the vorticity pattern formed behindthe bluff body Four prototypes were tested in a recirculatingwater channel with different types ofmaterial and dimensions


of the membrane and various Reynolds number It was foundthat lock-in phenomenon occurred to the membranes whenthey oscillated at the same frequency as the undisturbedwake behind the bluff body The frequency responses of themembrane were found to be independent of the length of themembrane but significantly sensitive to the bluff body sizeElectrical response (ie voltage or power) was not measuredin this study

Taylor et al [43] proposed a similar ldquoeelrdquo harvester toharvest energy from flowing water like in the estuary or evenin the open ocean A prototype of 9510158401015840 length 310158401015840 widthand 150 120583m thickness was fabricated with the commercialpiezoelectric polymer PVDF totally consisting of 8 segmentsThe prototype was tested in a flow tank and data on eachsegment were acquired separately A peak voltage around 3Vwas measured for the segment near the head bluff body at aflow speed of 05ms Measurements also showed that fromhead to tail distortion in the voltage output increased whilevoltage magnitude decreased The maximum power wasachieved when the flapping frequency matched the vortexshedding frequency It was pointed out that an optimumcentral layer and active layer thickness deserve further designefforts to obtain the optimum bending stiffness and thus themaximum strain

Robbins et al [44] proposed several methods to improvethe power extraction efficiency of an energy harvester withflexible piezoelectric material It was shown experimentallythat the efficiency could be enhanced by using windwardbluff body and adding mass to the free end of the flap-ping piezoelement Analytically it was shown that the useof stronger-coupling flexible piezoelectric materials suchas AFCs (active fiber composites) and MFCs (macrofibercomposite) could improve the efficiency by a factor of 25Moreover both experiment and analysis showed that usingthe quasi-resonant rectifier to extract electrical energy frompiezoelement instead of standard full-wave rectifier couldincrease the efficiency by a factor of 23

Pobering and Schwesinger [45] implemented a VIVenergy harvester similar to the energy harvesting eel inboth the air and water flow It was roughly determined thatavailable energy densities in flowing media are in the rangeof 256Wm2 in air at a wind speed of 10ms and 1600 kWm2in water at a flow speed of 2ms respectively Behind thefixed bluff body a piezoelectric bimorph cantilever wasattached instead of flexible membrane or polymer in sucha way that the cantilever would only deform in the firstvibration mode unlike in the case of the membrane orpolymer where undulating waves were generated along thelength With a simple analytical model the optimal ratio ofthe cantilever length L over the frontal dimension D of thewindward bluff body was calculated to be 119871119863 = 2125Three identical prototypes were fabricated and tested in a rowwith a cantilever length of 14mmwidth of 118mm thicknessof 035mm and bluff body frontal dimension of 1035mmThe wind speed giving the peak power varied for the threeprototypes depending on their positions A highest deflectionof 51120583mwas obtained at awind speed of 40ms on the secondcantilever A peak voltage of 08 V with a load resistance of1MΩ and a peak power of 0108mW with a matched load

resistance of 12 kΩ were measured at 45ms Measurementsin the water were not reported but it was predicted that lowerwater flow speed would lead to comparable high power sincethe energy density in water was around 1000 times higherthan that in air It was concluded that adjacent cantilevershad strong influences on each other which enhanced thedeflection and output power

In a subsequent study Pobering et al [46] conductedmore tests in both air and water Comparison of the windtunnel experimental results between two series confirmed theanalytical prediction of the optimal geometrical relationship119871119863 = 2125 It was also found that the cantilevers in arow were able to synchronously oscillate in flowing mediawith high density like water With a peak power of 0055mWobtained from a single piezoelectric layer at 40ms a totalpower output of around 1mW can be approximated for aseries of 9 cantilevers It was concluded that the power of theproposed harvesting system was sufficient to power sensorslogical circuits and wireless data transmission circuits

However among the above studies on VIV based energyharvesters no one has investigated the effect of electrome-chanical coupling on the electrical output or its backwardcoupling effect on the aeroelastic response Akaydin et al [47]were among the very first to consider the three-way couplingeffects that is the mutual coupling behaviors between theaerodynamics structural vibration and electrical responseIn their study a new type of energy harvester was pro-posed to harness flow energy based on the vortex sheddingphenomenon A piezoelectric cantilever was put behind awindward cylinder which was fixed as a bluff body Thedownstream end of the cantilever was fixed The cantileveroscillated in the fully turbulent vortex street formed at highReynolds number of 14842 Although the harvester wasclaimed to be designed for harnessing energy from highlyunsteady fluid flows if we consider the windward cylinder asa part of the energy harvester the flow in front of the cylinderwas smooth and steady as they were placed together in asmooth-flow-generating wind tunnel Therefore we reviewthis design in the section of ldquoenergy harvesters based onvortex-induced vibrationsrdquo In this study performance of thepiezoelectric cantilever inside a turbulent boundary layerwas also reported which we will introduce in the sectionof ldquoenergy harvesters based on turbulent induced vibrationrdquoExperimentally with a 30mm times 16mm times 02mm cantileverwith a piezoelectric layer of PVDF attached on the top surfaceand with a cylinder of 30mm in diameter and 12m inlength fixed in the windward direction a peak power of4 120583W was measured with a load of 100 kΩ at a wind speedof 723ms which produced a vortex shedding frequencyclose to the beamrsquos resonance frequency around 485HzSimulations based on CFD were conducted to solve the two-dimensional N-S (Navier-Stokes) equations to obtain theaerodynamic pressure which was substituted into a 1DOFelectromechanical model to calculate the voltage output Theelectromechanical coupling was assumed to be weak and thebackward coupling effect of the voltage generation on themechanical displacement response was reasonably ignoredAn explanation of the driving mechanism of the beamrsquososcillation was tried to be deduced from the simulation


results The induced flow ahead of the vortex impinges onthe beam and the overpressure resulting from the stagnationregion bends the beam at the same time on the oppositeside the core of another vortex applies suction driving thebeam in the same direction The mechanism was furtherconfirmed in a subsequent study with more simulations [48]It was found experimentally that the face-on configurationwhere the beam was parallel to the upstream flow is the bestorientation for the beam

In a subsequent study Akaydin et al [23] proposed anew self-excited VIV energy harvester to improve the outputpower The cylinder was different from the previous casesattached to the free end of an aluminum cantilever with PZTcovering the end area Periodic oscillations occurred in thedirection normal to the wind flow due to the vortex sheddingA peak power of around 01mW of nonrectified power wasobtained at a much lower wind speed of 1192ms with amatched load of 246MΩ Compared to the previous designthe aeroelastic efficiency (ie efficiency of converting the flowenergy into mechanical energy) was increased from 0032to 28 and the electromechanical efficiency (ie efficiencyof converting the mechanical energy into electrical energy)was increased from 11 to 26 It was concluded that themodified configuration of the attachment of the cylinder onthe cantilever tip and the employment of PZT instead ofPVDF greatly enhanced the power generation

In order to overcome the narrow operating range of VIV-based harvesters Weinstein et al [49] proposed an energyharvester with resonance tuning capabilities The piezoelec-tric cantilever was placed behind a cylinder bluff body andattached with an aerodynamic fin at the tip Small weightswere placed along the fin Manually adjustment of theweights positions could tune the resonant frequencies of theharvester making it able to operate at resonance for windvelocities from 2 to 5ms A peak power of nearly 5mWwas obtained at a wind speed of around 55ms But thelimitation is that this tuning mechanism is not automaticthus the wind velocity needs to be always stable and the exactwind velocity should be known before the installation of thisharvester

Different from the aforementioned studies which investi-gated the performance of the fabricatedVIV energy harvesterprototypes based on experiments or numerical simulationsBarrero-Gil et al [81] attempted to theoretically evaluate theeffects of the governing parameters on the power extractionefficiency The effects of the mass ratio 119898lowast (ie the ratioof the mean density of a cylinder bluff body to the den-sity of the surrounding fluid) the mechanical damping 120577and the Reynolds number were investigated with a 1DOFmodel where fluid forces were introduced from previouslypublished experimental data from forced vibration testsThere was no specific energy harvester design proposed Itwas shown that the efficiency was greatly influenced by themass-damping parameter 119898lowast120577 and there existed an optimal119898lowast120577 for peak efficiency at a specific Reynolds number Therange of reduced wind speeds with significant efficiency wasfound to be mainly governed by 119898lowast Also it was foundthat high efficiency could be achieved for high Reynoldsnumbers

Abdelkefi and his coworkers [82 83] theoretically ana-lyzed the influences of several parameters on the mechan-ical and electrical responses of a VIV harvester A flexiblysupported rigid cylinder was considered with a piezoelectrictransducer attached to the transverse degree of freedomThevortex shedding lift force was expressed by a van der Polequation Based on the lumped parameter model Abdelkefiet al [82] found that increasing the load resistance shifted theonset of synchronization to higher wind speeds A hardeningbehavior and hysteresis were observed in the displacementvoltage and power responses due to the cubic nonlinearityin the lift coefficient In a subsequent study of Mehmoodet al [83] the aerodynamic loads due to vortex sheddingwere obtained using CFD simulations and were subsequentlycoupled with the electromechanical model to predict theelectrical output It was found that the region of windspeeds at synchronizationwas slightlywidenedwhen the loadresistance increased An optimum value of load resistance formaximumpower outputwas determined to correspond to theload value with minimum displacement of the cylinder

Gao et al [50] proposed another configuration of har-vester consisting of a piezoelectric cantilever with a cross-flow cylinder attached to its free end of which the long axeswere arranged in parallel Prototypes were constructed andtested in both laminar flows generated by a wind tunnel andturbulent flows generated by an electric fan Experimentallyit was found that the power output increased with the windspeed and cylinder diameter Higher voltage and power weregenerated in the turbulent flow than in the laminar flow Itwas concluded that turbulence excitation was the dominantdriving mechanism of the harvester with additional contri-bution from vortex shedding excitation in the lock-in regionWith a piezoelectric cantilever of 31 times 10 times 0202mm3 and acylinder with a length of 36mm and a diameter of 291mm apeak power of 30 120583Wwas measured at a wind speed of 5msin the fan-generated turbulent flow

Instead of directly using the impinges of shedded vor-tices on the piezoelectric membrane or cantilever to inducemechanical oscillations Wang and his coworkers [51ndash53 84]developed energy harvesters in the form of a flow channelwith a flexible diaphragm The diaphragm was driven intovibration by vortex shedding from a bluff body placed in thechannel Piezoelectric film or magnet and coil are connectedto the diaphragm for energy transduction Experimentalresults showed that an instantaneous output power of 02 120583Wwas generated for the piezoelectric harvester under a pressureamplitude of 1196 kPa and a pressure frequency of 26Hz[51] and 177 120583W for the electromagnetic harvester under03 kPa and 62Hz [52] Subsequently Tam Nguyen et al[53] further investigated the effects of different bluff bodyconfigurations Two bluff bodies were placed in the flowchannel in a tandem arrangement to enhance the pressurefluctuation behind them A prototype was assembled withan embedded 02mm thick polydimethylsiloxane (PDMS)diaphragm on top surface of the flow channel two triangularbluff bodies with a base length of 425mm and an altitudeof 218mm inserted inside a PVDF film of 25mm times 13mm times0205mm glued to the acrylic bulge on top of the diaphragm


An open-circuit voltage of 14mV and an average power of059 nWweremeasured with the prototype at a wind speed of207ms The power is relatively low as compared with otherharvesters that have been reviewed It was suggested that thepower can be enhanced by optimizing the blockage ratioadjusting the position of the flexible diaphragm and usinga piezoelectric material with higher piezoelectric constantsThis harvester design was recommended to be deployedin the pipelines tire cavities or machinery by installing adiaphragm on the wall

Current studies on energy harvesting from VIV alsoinclude the investigation of the interaction of a single andmultiple vortices with a cantilever conducted by Goushchaet al [85] as an extension of the work by Akaydin et al[47 48] Particle image velocimetry was used to measurethe flow field induced by each controllable vortex andquantify the pressure force on the beam to give a betterunderstanding of the fluid-structure interactions The twodriving mechanisms of upstream flow impingement on oneside of beam and suction of the vortex core on the oppositeside [47 48] and the importance ofmatching the frequency ofappearance of vortices with the beamrsquos resonance frequencywere demonstrated clearly via the flow visualization

The necessity of achieving the synchronization regionfor energy harvesting from VIV was also demonstrated byWang et al [86] through modeling with computational fluiddynamics Recently VIV has been employed for large-scalewind energy harvesting with the so-called Vortex BladelessWind Generator [87] which is capable of generating highoutput power in the order of kW or even MW The size ofthis type of generator is tremendously increased as comparedto other devices investigated here for example it can bea few tens of meters high Table 2 compares the reportedfabricated prototypes based on vortex-induced vibrationswith regard to the transduction mechanism shape of bluffbody cut-in and cut-wind speed peak power and powerdensity dimension and their advantage disadvantage andapplicability

23 Energy Harvesters Based on Galloping It is not untilrecently that the aeroelastic instability phenomenon of trans-verse galloping is employed to obtain structural vibrations forenergy harvesting purpose Due to the self-excited and self-limiting characteristics of galloping it is a prospective energysource for energy harvestingMoreover compared to theVIVgalloping owns its advantages of large oscillation amplitudeand the ability of oscillating in infinite range of wind speedswhich are preferable for energy harvesting

Barrero-Gil et al [88] theoretically analyzed the potentialuse of galloping to harvest energy using a 1DOF modelThe harvesting system was modeled as a simple mass-spring-damper system No specific energy harvester designwas proposed The aerodynamic force was formulated usinga cubic polynomial based on the quasi-steady hypothesisTheoretically it was found that in order to achieve a highefficiency the bluff body should have a high aerodynamiccoefficient A1 and a low absolute value of A3 (generally1198601 gt0 1198602 = 0 and 1198603 lt 0) For the mechanical damping it wasdetermined that a low value of the mass-damper parameter

Table 3 Different cross-sections of bluff body in comparative studyof Yang et al [32]

Section shape

Dimensionℎ times 119889 (mm) 40 times 40 40 times 60 40 times 267 40 (side) 40 (dia)

119898lowast120577 should be used where m is the distributed mass of thebluff body Sorribes-Palmer and Sanz-Andres [89] continuethe study by obtaining the aerodynamic coefficient curve119862119911(120572) directly from the experimental data instead of usinga polynomial fitting It was found that directly obtaining119862119911(120572) from experiment can avoid problems associated withpolynomial fitting like wrong dynamic responses induced byinaccurate polynomials

A galloping energy harvester consisting of two cantileverbeams of 161 times 38 times 0635mm3 and a prism with equilateraltriangular cross-section of 40mm in each side and 251mmin length attached to the free ends was proposed by Sirohiand Mahadik [54] A coupled electromechanical model wasestablished based on the Rayleigh-Ritz method and the aero-dynamic model was based on the quasi-steady hypothesisDue to the large size and high coupling coefficient of thepiezoceramic sheets a high peak power was achieved asmorethan 50mWat a wind velocity of 116mph (around 52ms) inthe laminar flow condition But an abrupt decrease in outputpower occurred at 136mph which was not in consistencewith the galloping mechanism The authors attributed thisdecrease to the large-scale turbulence in the wind tunnel

Another galloping energy harvester using a tip bodywith D-shaped cross-section connected in parallel with apiezoelectric composite cantilever was developed by Sirohiand Mahadik [55] with a dimension of 30mm in diameterand 235mm in length for the tip body and 90 times 38 times0635mm3 for the cantilever The wind flow was generatedby an axial fan which was associated with a highly turbulentprofile The measured voltage generated by the piezoelectricsheets showed that a stable limit cycle oscillation could beobtained for the steady state response Also the frequencyof oscillation was found to be equal to the natural frequencyof the cantilever The power output was observed to con-tinuously increase with the wind speed A maximum powerof 114mW was obtained at a wind speed of 105mph Thewide operational wind speed range is a great benefit of energyharvesters based on galloping

A comparative study of different bluff body cross-sectionsfor small-scale wind energy harvesting based on gallopingwas conducted by Zhao et al [56] and Yang et al [32] Windtunnel experiment was carried out with a prototype deviceconsisting of a piezoelectric cantilever and a bluff body withvarious cross-section profiles Square rectangle triangle andD-shape were considered as shown in Table 3 Figure 1 showsan example of the schematic and fabricated prototype ofthe galloping energy harvester with a square bluff bodyResponses of power versus load resistance showed that thereexisted an optimal load value for maximum output powerMoreover it was experimentally determined for the first time


Table4Summaryof

vario

usgallo

ping

energy

harvesterd

evices

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

per

volume(mWcm3)

Advantagesdisa

dvantagesa

ndother

inform

ation

Sirohi

and

Mahadik[54]

Piezoelectric

Triang

le36

61

5052

Bluff

body

4c

min

side251cm

inleng

th

cantilever161times38times

00635

cm3

0281

(i)Highpeak

power

isachievedw

ithhigh

electromechanicalcou

pling

(ii)V

alidates

thefeasib

ilityof

predictin

ggallo

ping

energy

harvesterrsquos

respon

sewith

quasi-steadyhypo

thesis

(iii)Ab

rupt

decrease

inou

tput

power

at61m

sisun

desired

Sirohi

and

Mahadik[55]

Piezoelectric

D-shape

25

mdash114

47

Bluff

body

3cm

india

235cm

inleng

th

cantilever

9times38times00635

cm3

00134

(i)Outpu

tpow

ercontinuo

uslyincreases

with

windspeedwith

nocut-o

utwind

speed

(ii)W

ideo

peratio

nalw

indspeedrang

e(iii)Re

quiring

turbulentfl

owto

functio

nwellfore

xampleflo

wfro

mar

otatingfan

becauseD

-shape

cann

otself-oscillatein

laminar

flow

(iv)C

antilever

andbluff

body

prism

arein

parallel

Zhao

etal[56]

Yang

etal[32]

Piezoelectric

Square

25

mdash84

80

Bluff

body

4times4times

15cm3

cantilever

15times3times006

cm3

00346

(i)Ex

perim

entally

determ

iningforthe

first

timethatthe

square

sectionisop

timalfor

gallo

ping

energy

harvestin

gcomparedto

othershapesgiving

thelargestpo

wer

and

thelow

estcut-in

windspeed

(ii)H

ighpeak

power

isachievedw

ithhigh


pling

(iii)Wideo

peratio

nalw

indspeedrang

e

Zhao

etal[57]

Piezoelectric

Square

10mdash

450

Bluff

body

4times4times

15cm3

cut-o

utcantileverinner

beam

57times3times

003

cm3

outerb

eam172times66times

006

cm3with

cuto

utat

theinn

erbeam

locatio

n

00162

(i)2D

OFcut-o

utstr

ucture

with

magnetic

interaction

(ii)R

educingthec

ut-in

speed

(iii)En

hancingou

tput

power

inthelow

windspeedrang

e(iv

)Havingstiffn

essn

onlin

earityindu

ced

bymagnetic

interaction

(v)O

utpu

tpow

erislim

itedin

high

wind

speeds

Zhao

andYang

[24]

Piezoelectric

Square

20

mdash12

80

Bluff

body

4times4times

15cm3


006

cm3

beam

stiffener8times45times

05c

m3

00455

(i)Em

ployed

beam

stiffenera

sele

ctromechanicalcou

plingmagnifier

(ii)E

ffectivefor

allthree

typeso

fharvestersbasedon

gallo

ping

vortex-in

ducedvibrationandflu

tterwith

greatly

enhanced

output

power

(iii)Disp

lacementisn

otincreasedthus

notaggravatin

gfatig

ueprob

lem

(iv)E

asyto

implem

ent

(v)C

ut-in

windspeedisun

desir

ably

increased


Table4Con

tinued

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

per

volume(mWcm3)

Advantagesdisa

dvantagesa

ndother

inform

ation

Zhao

etal[3358]

Piezoelectric

Square

35

mdash114

50

Bluff

body

2times2times

10cm3


006

cm3

00274

(i)Em

ployed

synchron

ousc

harge

extractio

n(SCE

)elim

inates

the

requ

iremento

fimpedancem

atchingand

ensuresthe

flexibilityof

adjusting

the

harvesterfor

practic

alapplications

(ii)S

aving75

ofpiezoelectric

materials

bytheS

CEcomparedto

thes

tand

ard

circuit

(iii)Ac

hievingsm

allertransverse

displacementand

alleviatingfatig

ueprob

lem

with

SCE

Zhao

etal[5960]

Piezoelectric

Square

30

mdash325

70

Bluff

body

2times2times

10cm3


006

cm3

00782

(i)Synchron

ized

switching

harvestin

gon

indu

ctor

(SSH

I)enhances

output

powe

rcomparedto

stand

ardcircuit

(ii)S

SHIsho

wsm

ores

ignificantb

enefits

inweak-coup

lingsyste

msyetloses

benefitsinstr

ong-coup

lingcond

ition

s(iii)Ac

hieving143

power

increase

at7m

s

Bibo

etal[61]

Piezoelectric

Square

asymp22

mdash0348lowast1

45

Bluff

body

508times508times

1016

cm3


003

cm3

00013

(i)Con

currentfl

owandbase

excitatio

nsenhances

energy

harvestin

g(ii)B

asee

xcitatio

nim

proves

electrical

output

inresonancer

egion

(iii)Electricalou

tput

drop

sifb

ase

excitatio

nfre

quency

isclo

seto

buto

utsid

eof

resonancer

egion

Ewerea

ndWang

[62]

Piezoelectric

Square

2mdash

138

Bluff

body

5times5times

10cm3


004

cm3

bumpsto

pgapsiz

e05c

mcon

tactarea127

times4c

m2location

13cm

alon

gcantilever

00512

(i)Incorporatingan

impactbu

mpsto

psuccessfu

llyrelievesthe

fatig

ueprob

lem

(ii)A

chieving

substantial70

redu

ctionin

displacementamplitu

dewith

only20

voltage

redu

ction

lowast1Ca

lculated

by(59V)210

0kΩfro

mtheinformationgivenin

Table1

andFigure12of

ther

eference


Table5Summaryof

vario

usflu

ttere

nergyharvesterd

evices

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Bryant

and

Garcia[

63]

Bryant

and

Garcia[

26]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoilprofi

leNAC

A0012

186

mdash22

79

Airfoilsemicho

rd297

cmspan136cm

Ca

ntilever254times254times

00381cm3

717times10minus3

(i)Semiempiric

almod

elof

then

onlin

ear

electromechanicaland

aerodynamicsyste

maccuratelypredictedele

ctric

alandmechanical

respon

se

(ii)S

uccessfully

predictsthefl

utterb

ound

arywith

oneo

fthe

realpartso

fthe

firsttwoeigenvalues

turningpo

sitivea

ndthetwoim

aginaryparts

coalescing

(iii)Wideo

peratio

nalw

indspeedrang

e(iv

)Sub

criticalH

opfb

ifurcation

alarge

initial

distu

rbance

isfund

amentalfor

syste

msta

rtup

Bryant

etal[64

]Piezoelectric

Mod

alconvergence

flutte

rFlatplate

Stiff

hoststr

ucture

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

Stiff

host

structure

(i)Com

paredto

astiff

hoststr

ucturea

compliant

hoststr

ucture

redu

cesthe

cut-inwindspeed

cut-infre

quency

andoscillatio

nfre

quency

(ii)Th

epeakpo

wer

isshifted

towardthelow

erwindspeeds

with

thec

ompliant

hoststr

ucture

173

2943

26200

Com

pliant

hoststr

ucture

Com

pliant

hoststr

ucture

152

2935

25163

Bryant

etal[65]

Piezoelectric

Mod

alconvergence

flutte

rFlatplate

173

2943

26

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

200

(i)Con

firmsthe

feasibilityof

usingam

bientfl

owenergy

harvestin

gto

power

aerodynamiccontrol

surfa

ces

Erturk

etal[66

]Piezoelectric

Mod

alconvergence

flutte

rAirfoil

930

mdash107

930

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

227times10minus3

(i)Eff

ecto

felectromechanicalcou

plingon

flutte

renergy

harvestin

gisanalyzed

(ii)F

ound

thattheo

ptim

alload

gave

the

maxim

umflu

tterspeed

duetothea

ssociated

maxim

umshun

tdam

ping

effectd

uringpo

wer

extractio

n

Sousae

tal[67]

Piezoelectric

Mod

alconvergence

flutte

rAirfoil

Linear

confi

guratio

n

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

Linear

confi

guratio

n255times10minus3

(i)Th

efreep

layno

nlinearityredu

cesthe

cut-in

windspeedandincreasedtheo

utpu

tpow

er

(ii)Th

eoreticallydeterm

iningthattheh

ardening

stiffn

essb

rings

ther

espo

nsea

mplitu

deto

acceptablelevelsandbroadens

theo

peratio

nal

windspeedrang

e

121

mdash12

121

With

freep

layno

nlinearity

With

freep

lay

nonlinearity

100

mdash27

100

573times10minus3

Bibo

andDaqaq

[68]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoil

profi

leNAC

A0012

23

mdash0138lowast1

3(W

ithbase

acceleratio

n015ms2)

Airfoilsemicho

rd42c

mspan52c

m

Cantilevermdash

838times10minus4

(i)Con

currentfl

owandbase

excitatio

nsenhances

power

generatio

nperfo

rmance

(ii)C

oncurrentexcitatio

nsincreaseso

utpu

tpo

wer

by25tim

esbelowthefl

utterspeedand

over

3tim

esabovethe

flutte

rspeed

(iii)Ab

ovethe

flutte

rspeedrequirin

gcareful

adjustm

entb

ecause

power

issensitive

tobase

acceleratio

nfre

quency

Kwon

[69]

Piezoelectric

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

40

15

Flatplatetip60times

30c

m2


002

cm3

256

(i)SimpleT

-shape

structureeasyto

fabricate

(ii)N

orotatin

gcompo

nents

(iii)Wideo

peratio

nalw

indspeedrang

e


Table5Con

tinued

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Park

etal[70]

Electro

magnetic

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

118

Flatplatetip30times

20c

m2


001016c

m3

582

(i)Determiningthattheo

nsetof

theh

arveste

rrequ

iresthe

load

resistancetosurpassthe

flutte

ron

setresistance

Lietal[71]

Piezoelectric

cross-flo

wflu

tter

mdash4

mdash0615

8adhereddo

uble-la

yer

stalk72times16times

004

1cm3

130

(i)Cr

oss-flo

wconfi

guratio

ngeneratedon

eorder

ofmagnitude

morep

ower

than

thep

arallel

confi

guratio

n(ii)H

avinghigh

power

density

perw

eightand

per

volume

(iii)Be

ingrobu

stsim

pleandminiature

sized

(iv)B

eing

easy

toblendin

urbanandnatural

environm

entsdu

etoits

ldquoleafrdquoa

ppearance

Deivasig

amaniet

al[72]

Piezoelectric

cross-flo

wflu

tter

Triang

lemdash

mdash00883

8

Isoscelestria

ngletip

8c

min

base8

cmin

height035

mm

inthickn

ess

Stalk72times16times

00205

cm3

00651

(i)Determiningthatverticalsta

lkconfi

guratio

nis

superio

rtotheh

orizon

talstalkwith

fivetim

esmoreo

utpu

tpow

er

Hum

ding

erElectro

magnetic

cross-flo

wflu

tter

mdashmdash

mdashasymp9lowast2

10lowast3

Mem

brane12times07c

m2

Casin

g13times3times25c

m3

0923

(i)Successfu

llypo

wersw

irelesssensor

nodes

(ii)B

eing

compactandrobu

st(iii)Lo

wcut-inwindspeedandwideo

peratio

nal

windspeedrang

e

Hob

ecketal[73]

Piezoelectric

Dual

cantilever

flutte

rmdash

asymp3

mdash0796

asymp13

Twoidentic

alcantilevers146times254times

00254

cm3

0422

(i)Ve

rywideo

peratio

nalw

indspeedrang

ewith

efficientp

ower

generatio

n(ii)G

eneratingas

ignificantamou

ntof

power

from

3msto

15mswhengapissm

all

lowast1Ca

lculated

by18mwgtimes(015

ms298ms2)2

from

theinformationgivenby

thea

utho

rsof

ther

eference

lowast2lowast3Obtainedfro

mthefi

gure

inthed

atasheetof120583icroWindb

elt(http

wwwhu

mdingerwindcompdfm

icroBe

lt_briefp

df)


Table6Summaryof

vario

uswakeg

alloping

energy

harvesterd

evices

Author

Transductio

nPrism

shape

Cut-in

wind

speed

(ms)

Cut-o

utwind

speed

(ms)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Jung

andLee

[27]

Electro

magnetic

Circular

cylin

der

asymp12

mdash3704

45

Twoidentic

alcylin

ders5

cmin

dia

85cm

inleng

th

Spacingdistance

5times119863=25

cm

0111

(i)Determiningthep

roper

dista

nceb

etweenthep

arallel

cylin

dersforw

akeg

alloping

energy

harvestin

gas

4-5tim

esthec

ylinderd

iameterthatis

119871119863

=4sim

5(ii)H

ighou

tput

power

(iii)Wideo

peratio

nalw

ind

speedrange

(iv)D

evicev

olum

eistoo

big

Abdelkefi

etal[74]

Piezoelectric

Windw

ard

circular

cylin

der

Leew

ard

square

cylin

der

04

mdash004sim005

305

Circular

cylin

der

125c

min

dia

2715

cmin

leng

th

Square

cylin

der

128times12

8times

2667c

m3

Spacingdistance

24cm

Piezoelectric

two

identic

alcantilevers1524times

18times00305

cm3

572times10minus4

(i)Po

wer

from

agalloping

square

cylin

derw

asgreatly

enhanced

bywakee

ffectso

fanup

stream

circular

cylin

der

(ii)O

peratio

nalw

indspeed

rangew

aswidened

bywake

gallo

ping

(iii)Diameter

oftheu

pstre

amcylin

dera

ndthes

pacing

distance

betweentwocylin

dersrequ

irecarefuladjustm

ent


Table7Summaryof

vario

usTIVenergy

harvesterd

evices

Author

Transductio

nCu

t-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Akaydin

etal

[47]

Piezoelectric

asymp5lowast1


11

Bluff

body

3cm

india

12m

inleng

th

Cantilever3times16

times002

cm3

Distance

from

the

wall4c

m

648times10minus8

(i)Perfo

rmance

ofharvesterin

turbulentb

ound

arylayer

depend

sonthed

istance

from

the

walldo

minanto

scillation

frequ

ency

was

close

totheb

eam

resonancefrequ

ency

Hob

eckand

Inman

[28]

Piezoelectric

9sim10lowast2

mdash40

115

Bluff

body

445times

445times1092c

m3

Four

identic

alcantileversin

anarray1016

0mmtimes

2540m

mtimes

1016

0120583m

steel

substratea

ttached

with

4597m

mtimes

2057m

mtimes

15240120583m

PZT

00184

(i)Th

efirstT

IVenergy

harvestin

gmod

elwith

experim

entalvalidation

(ii)B

eing

robu

standsurvivable

duetoits

inherent

redu

ndancy

with

minor

redu

ctionin

total

power

caused

byon

edam

aged

elem

ent

(iii)Suitablefor

high

lyturbulent

fluid

flowenvironm

entslik

estr

eamso

rventilationsyste

ms

lowast1Obtainedfro

mtheinformationof

Figure11of

ther

eference

lowast2Obtainedfro

mtheinformationof

Figure7(b)o

fthe

reference


Table 8 Summary of other types of energy harvester devices

Author Transduction

Cut-inwindspeed(ms)

Cut-outwindspeed(ms)

Maximumpower(mW)

Windspeed at

max power(ms)

Dimensions

Powerdensity pervolume

(mWcm3)

Advantagesdisadvantagesand other information

Bibo etal [75] Piezoelectric asymp55lowast1 mdash 005 75

Cantilever 58 times1626 times 0038 cm3Chamber volume

2300 cm3217 times 10minus5

(i) Mimicking the basicphysics of music-playingharmonicas(ii) Using optimal chambervolume and decreasingaperturersquos width reduce thecut-in wind speed

OvejasandCuadras[76]

Piezoelectric mdash mdash 00002 123

Two identical bluffbodies 05 cm in

diaPiezoelectric film156 cm times 19 cm times

40120583m

125 times 10minus5

(i) Bluff body configurationoutperformed the one fixedside and two fixed sideconfigurations(ii) Rotational turbulentflow from a dryer added tovortex shedding effectsgiving higher electricaloutput than the laminarflow did

lowast1Obtained from the information of Figure 13(b) of the reference

Z

h

dX

(a)

Lp

L tip

Lb

tp tbBp Bb

(b)

Figure 1 (a) Schematic and (b) fabricated prototype of galloping energy harvester with a square bluff body [32]

that the square section generates the largest power and has thelowest cut-in wind speed among all the considered sectionsWith a 150mm times 30mm times 06mm cantilever and a 40mm times40mm times 150mm bluff body a peak output power of 84mWwas measured at a wind speed of 8ms with the optimal loadresistance which is sufficient to power a commercial wirelesssensor node A 1DOF model was used which successfullypredicted the power responseMoreover the analysis with thegalloping force represented with a seventh order polynomialpredicted a hysteresis region of output power which was notcaptured in the experiment due to the unavoidable turbulentflow component in the wind tunnel It was recommendedthat the square section should be used for small-scale windgalloping energy harvesters

Abdelkefi et al [90] theoretically investigated the conceptof using a galloping square cylinder to harvest energy Anormal form solution was provided to validate the numericalsolution of the employed 1DOF model with both solutionsconfirming that the instability of galloping is a supercriticalHopf bifurcation phenomenon Theoretically it was foundthat for low Reynolds the onset of galloping (cut-in wind

speed) and output power increased while the displacementdecreased with the load resistance while for high Reynoldsthere existed an optimal load with which maximum outputpower maximum onset of galloping and minimum dis-placement were achieved simultaneously Abdelkefi et al [91]considered more shapes of bluff body including square twoisosceles triangles (120575 = 30∘ for one and 120575 = 53∘ for the otherwith 120575 being the base angle) and D-section Theoreticallythe isosceles triangle with 120575 = 30∘ was recommended forsmall wind speeds while the D-section was recommended forhigh wind speeds It should be noted that the aerodynamiccoefficients used to calculate the galloping force are muchsensitive to the flow condition (laminar or turbulent) whichhas great influences on the galloping behavior of differentcross-sections For example turbulence in the flow can sta-bilize the square section while it destabilizes the D-sectionThat is why the D-section cannot oscillate in the wind tunnelas shown by Zhao et al [56] but it can gallop when placed infront of an axial fan [55]

In order to better understand the electroaeroelasticbehaviors and provide a guideline to optimize the galloping


piezoelectric energy harvester Zhao et al [92] conducted acomparison of different modeling methods to weigh theirvalidity advantages and disadvantages The 1DOF modelsingle mode Euler-Bernoulli distributed parameter modelandmultimode Euler-Bernoulli distributed parameter modelwere compared and validated with wind tunnel experimenton a prototype with a square sectioned bluff body It wasfound that all these models can successfully predict thevariation of the average power with the load resistance andthe wind speed Higher modes especially were found notnecessary in modeling since minor difference was observedbetween the single mode and multimode Euler-Bernoullidistributed parameter models It was concluded that thedistributed parameter model has a more rational represen-tation of the aerodynamic force while the 1DOF modelgives a better prediction of the cut-in wind speed and ownsits merit for conveniently obtaining the electromechanicalcoupling coefficient for a fabricated prototype via directmeasurement The parametric study showed that increasingthe wind exposure area and decreasing the mass of the bluffbody can increase the output power and reduce the cut-in wind speed Moreover in order to obtain the maximumpower density (ie power per piezoelectric volume) it wassuggested that a medium-long piezoelectric patch be usedwith careful sweep calculation

A big issue of small-scale wind energy harvesting isthat most piezoelectric aeroelastic energy harvesters operateeffectively only at high wind speeds or within a narrow speedrange To overcome this issue that is to reduce the cut-in wind speed and enhance output power in the low windspeed range (eg lower than 5ms) which is typical forheating ventilation and air conditioning (HVAC) systemsrsquoflow condition Zhao et al [57] proposed a 2DOF piezo-electric galloping energy harvester with a cut-out cantileverand two magnets which induces stiffness nonlinearity of thewhole system as shown in Figure 2Wind tunnel experimentconfirmed its effectiveness obtaining a reduced cut-in speedof 1ms and nearly four-time increase in power at 25mswith a magnet gap of 8mm as compared to the conventional1DOF harvester The total output power was found to beenhanced in the low wind speed range up to 45ms Itwas concluded that the proposed 2DOF galloping harvesteris suitable for powering wireless sensing nodes for indoormonitoring applications and highly urbanized areas withonly low speed wind flows available Subsequently Zhaoand her coworkers [24 25 33 58ndash60] further enhancedthe energy harvesting efficiency from both mechanical andcircuit aspects by amplifying the electromechanical couplingwith a beam stiffener and using nonlinear power extractioncircuit which will be reviewed withmore details in Section 3

Bibo and Daqaq [93 94] established a universal rela-tionship between the dimensionless output power and thedimensionless wind speed for galloping energy harvesterswhich was shown to be only sensitive to the aerodynamicproperties of the bluff body but independent of the mechan-ical or electrical design parameters of the harvester Thisrelationship significantly facilitates the optimization analysisand comparison of performances of different bluff bodies Itwas found that when all harvesters are optimally designed

Wind

Bluff body

Inner beam

Outer beam

Magnets

Piezoelectricpatches

Fixed end

Figure 2 Schematic of 2DOF piezoelectric galloping energy har-vester for power enhancement at low wind speeds

a squared-section bluff body always outperformed the D-shaped and triangular sectioned bluff bodies which agreeswith the findings of Yang et al [32] and Zhao et al [56]A 53∘ isosceles-triangular section harvester was found tooutperform the D-shaped one at high wind speeds butunderperform the D-shaped one at low wind speeds

Daqaq [95] subsequently incorporated the actual windstatistics in the responses of galloping energy harvesters byfitting wind data using Weibull Probability Density Function(PDF) It was concluded that the wind speed statistics areessential for accurate load optimization An exponentiallycorrelated PDF was found to generate higher power than aRayleigh distribution which in turn produces higher powerthan a known wind speed located at the distribution average

Ewere and Wang [62] employed the Krylov-Bogoliubovmethod to obtain analytical approximate solutions for gal-loping energy harvesters and found that the harvester witha square sectioned bluff body can outperform the rectangularsectioned one for all cases of load resistance and wind speedIn a subsequent study of Ewere et al [96] a bump stopwas introduced to relieve the fatigue problem of a gallopingenergy harvester Using an optimal bump stop design with agap size of 5mm at the location of 130mm along the beam oflength 228mm and a contact surface area of 127 times 40mm2a maximum 20 voltage reduction with substantial 70reduction in limit cycle oscillation amplitude was observedfrom the wind tunnel experiment It was concluded thatthe service life of a galloping harvester can be significantlyimproved by incorporating an impact bump stop

Continuing the feasibility study of harvesting energyfrom transverse galloping conducted by Barrero-Gil et al[88] Vicente-Ludlam et al [97] carried out a theoreticalstudy of a galloping electromagnetic energy harvester by


h

U

kh

휃

k휃

Figure 3 Schematic of an airfoil undergoing modal convergenceflutter

introducing the electromagnetic transduction mechanisminto the 1DOF galloping system It was found that withthe load resistance tuned to the optimal value for eachwind speed the power extraction efficiency can remainhigh over a larger range of wind speeds as compared to afixed value of the load resistance In a subsequent studyVicente-Ludlam et al [98] proposed a dual mass gallopingelectromagnetic energy harvesting system to enhance theenergy extraction It was shown theoretically that when themechanical properties were properly adjusted putting theelectromagnetic generator between the secondary mass anda fixed wall or between the main and the secondary massescan improve the energy extraction efficiency and broadenthe effective range of the wind speeds for energy harvestingTable 4 presents a summary and quantitative comparison ofthe discussed harvesters based on galloping

24 Energy Harvesters Based on Flutter Numerous designsof energy harvesters based on flutter instabilities have beenreported under axial flow conditions [99ndash105] or cross-flowconditions [71 106] with flapping airfoil designs [63 66 107]or tree-inspired [71] and infrastructure-inspired designs [69]Examples of flutter based harvesters include the wind belt[108] and flutter mill [109] The main types of flutter basedenergy harvesters include those based onmodal convergenceflutter and those based on cross-flow flutter which arereviewed in detail in the following sections Moreover a newtype of flutter energy harvester named dual cantilever flutter[73] is also discussed

241 Energy Harvesters Based on Modal Convergence FlutterAmong the explosive studies on small-scale wind energyharvesting based on aeroelastic flutter flapping airfoil orflapping wing based designs have been the most enthusias-tically pursued Schematic of an airfoil undergoing modalconvergence flutter with coupled pitch-plunge motions isshown in Figure 3 Energy harvesting based on airfoil flutterhas been reported a few decades ago by Bade [110] andMcKinney and DeLaurier [111] using electromagnetic trans-duction mechanism A patent has been filed by Schmidt [112]using two oscillating blades with piezoelectric transductionmechanism The so-called ldquooscillating blade generatorrdquo wastested in a later study [113] and it was concluded that apower density of order 100 watts per cm3 of piezoelectricmaterial is theoretically possible to be achieved In therecent years along with the explosive research on energyharvesting with piezoelectric materials piezoelectric wind

energy harvesting via airfoil flutter has become a hot researcharea with numerous studies reported

Bryant and Garcia [26 63] and coauthors [64 65 114ndash116] are among the very first to investigate the feasibility ofpiezoelectric energy harvesting with airfoil flutter An airfoilflutter based energy harvester was first reported by Bryantand Garcia [63] with both wind tunnel experimental resultsand theoretical predictions and further studied with a moredetailed theoretical modeling process [26] A piezoelectricbimorph was connected to a rigid airfoil (NACA0012 airfoilprofile) at the tip with a revolute joint permitting bothtransverse and rotary displacement of the airfoil Theoreticalanalyses were carried out to predict behaviors of the harvesterat the flutter boundary with linear models and during limitcycle oscillations above the flutter boundary with nonlinearmodels The linear mechanical model incorporating elec-tromechanical coupling was established using the energymethod based on the Hamiltonrsquos principle while the linearaerodynamic model was established based on the finite-state unsteady thin-airfoil theory of Peters et al [117] Smallangle and attached flow assumptions were taken in thelinear models For the nonlinear models large flap deflectionangles and flow separation effects were taken into accountWind tunnel experimental results of a fabricated harvesterprototype agreed well with the analytical predictions Theprototype consisted of a 254 times 254 times 0381mm substratecantilever attachedwith twoPZTpatches of dimension 460times206 times 0254mm and an airfoil with a semichord of 297 cmand a span of 135 cm A cut-in wind speed of 186ms wasobtained Amaximumoutput power of 22mWwas deliveredto an optimal load of 277 kΩ at a wind speed of 79ms Itwas concluded that collating and superposing the bender andsystem resonances can maximize the output power

In a subsequent work of Bryant et al [114] a parameterstudy was performed both experimentally and analytically toinvestigate the influence of several system design parameterson the cut-in wind speed It was found that the cut-inwind speed could be minimized by modifying the hingestiffness and the flap mass distribution yet its variation wasless sensitive to the hinge stiffness when large damping wasintroduced Later Bryant et al [115] compared the quasi-steady aerodynamic model with the semiempirical modelconsidering dynamic stall effects It was concluded that thequasi-steady model was applicable only for low flappingfrequencies while the dynamic stall model can be used topredict trustworthy results at high frequencies Bryant etal [64] also investigated the influence of the complianceof the host structure on the behavior of the airfoil flutterbased energy harvester Experimentally it was found that acompliant host structure reduced the cut-in wind speed cut-in frequency and oscillation frequency during the limit cycleoscillation and shifted the peak power toward the lower windspeeds as compared to a stiff host structure Bryant et al[116] presented an experimental study on energy harvestingefficiency and found that the peak power density and powerextraction efficiency of the flutter energy harvester occurredat the lowest wind tested due to the small swept area ofthe device At that wind speed which was near the flutterboundary the limit cycle oscillation frequency matched the


first natural frequency of the piezoelectric structure Whenthe wind speed increased the output power the swept areaof the device and available power in the flow also increasedbut power density and power extraction efficiency decreasedPreliminary study of implementing synchronized switchingapproaches like the synchronized switching and dischargingto a storage capacitor through an inductor (SSDCI) techniquein an aeroelastic flutter energy harvester was conducted witha separate microcontroller working as the peak detectorHowever the efficiency increasing capability of the SSDCIin flutter energy harvesting was not thoroughly studiedSubsequently Bryant et al [65] experimentally demonstratedthe concept of using ambient flow energy harvesting topower aerodynamic control surfaces With a prototype thatproduced a power of 43mW at a wind speed of 26ms itwas shown that the system produced more than 55∘ of tabdeflection over approximately 07 seconds after the storagecapacitor was charged for 235 seconds at 322ms It wasfound that the harvester was still able to produce power whenthe host control surface was rotated to a large angle of attackover 50∘ confirming the feasibility of the alternative design ofplacing the harvester on the control surface itself

Erturk and coauthors [66 67 118ndash121] are also amongthe first to study harnessing flow energy via the aeroelasticflutter of airfoils The concept of energy harvesting frommacrofiber composites with curved airfoil section was firstproposed by Erturk et al [118] Later Erturk et al [66]presented an experimentally validated lumped-parameteraeroelastic model for the flutter boundary condition Thelinear lift and moment at flutter boundary were modeledwith the Theodorsenrsquos unsteady thin airfoil theory Usinga flexibly supported airfoil prototype with a semichord of0125m and a span length of 05m a power of 107mWwas measured at the linear flutter speed of 930ms withan optimal load of 100 kΩ It was found both theoreticallyand experimentally that the optimal load gave the maximumflutter speed due to the associated maximum shunt dampingeffect during power extraction It was recommended thata nonlinear stiffness component andor a free play can beincorporated to induce stable limit cycle oscillations aboveand below (in the case of subcritical Hopf bifurcation) theflutter boundary for useful power generation In order toobtain stable limit cycle oscillations above or below the flutterboundary nonlinearity has to be introduced into the systemwhich can be either structural nonlinearity or aerodynamicnonlinearityThe structural nonlinearity suggested by Erturket al [66] and the aerodynamic nonlinearity modeled inBryant and Garcia [26] can both ensure the acquisition ofstable and large-amplitude limit cycle oscillations beyond thelinear flutter speed and harvest energy in a wide wind speedrange

In a subsequent study Sousa et al [67] theoreticallyand experimentally investigated the advantages of exploitingstructural nonlinearities in the piezoaeroelastic energy har-vesting system Piezoelectric coupling was introduced to theplunge DOF while structural nonlinearities were introducedto the pitch DOF aiming to solve the problem of a linearpiezoaeroelastic energy harvester that is having persistentoscillations only at the flutter boundary thus leading to a

very limited condition for energy harvesting It was shownboth theoretically and experimentally that the free playnonlinearity reduced the cut-in wind speed by 2ms anddoubled the output powerTheoretically it was found that thehardening stiffness helped to broaden the operational windspeed range It was concluded that the combined structuralnonlinearities can be introduced to enhance the performanceof aeroelastic energy harvesters based on piezoelectric andother transduction mechanisms

De Marqui and Erturk [119] theoretically analyzed theperformance of two airfoil-based aeroelastic energy har-vesters with piezoelectric and electromagnetic couplingsinserted to the plunge DOF separately It was found that opti-mal values of load resistance giving the largest flutter speed aswell as the maximum output power for the considered rangeof dimensionless equivalent capacitance and dimensionlesselectromechanical coupling in the piezoelectric configurationexisted For the electromagnetic configuration increasingthe load resistance reduced the flutter speed for any dimen-sionless inductance or electromechanical coupling and theoptimum load resistancematched the internal coil resistancewhich agreed with the maximum power transfer theorem

Subsequently Dias et al [120] theoretically analyzed theperformance of a hybrid airfoil-based aeroelastic energy har-vester using simultaneous piezoelectric and electromagneticinduction It was shown that in the electromagnetic induc-tion the internal coil resistance affected the flutter speed anddeteriorated the performance of the system The parameterstudy showed that the combination of low dimensionlessradius of gyration low pitch-to-plunge frequency ratio andlarge dimensionless chord-wise offset of the elastic axis fromthe centroid enhanced the performance by increasing theoutput power as well as decreasing the cut-in wind speed

Later Dias et al [121] continued the study of the hybridaeroelastic energy harvester with combined piezoelectric andinductive couplings based on a 3DOF airfoil A controlsurface was introduced bringing in a third displacement thatis the control surface displacement Theoretical parametricstudy showed that increasing the dimensionless radius ofgyration dimensionless chord-wise offset of the elastic axisfrom the centroid and control surface pitch-to-plunge fre-quency ratio and decreasing the pitch-to-plunge frequencyratio increased the power output and reduced the cut-in speed It was concluded that the 3DOF configurationenhanced the performance of the harvester by offering abroader design space and set of parameters for systemoptimization

Earliest studies of airfoil-based aeroelastic energy har-vesters also include the work of Abdelkefi et al [107 122]Abdelkefi et al [122] theoretically investigated the perfor-mance of an airfoil-based piezoaeroelastic energy harvesterwith the method of normal form which was validated bythe numerical integrations It was found that the systemrsquosinstability to the subcritical type depended significantly onthe cubic nonlinearity of the torsional spring In a subsequentstudy Abdelkefi et al [107] implemented two linear velocityfeedback controllers to reduce the flutter speed to anydesired value and hence generate energy from limit cycleoscillations at any desired low wind speed This was realized


by introducing two vibration velocity dependent terms intothe system governing equations It was found theoreticallythat the aerodynamic nonlinearity produced a supercriticalbifurcation while the cubic stiffness nonlinearity producedsupercritical or subcritical bifurcation depending on whetherthe stiffness nonlinearity was hard or soft

Instead of harvesting energy only from flowing windBibo and Daqaq [123] theoretically investigated the perfor-mance of an airfoil-based piezoaeroelastic energy harvesterwhich concurrently harvested energy from ambient vibra-tions and wind by introducing harmonic base excitation inthe plunge direction The nonlinear aerodynamic lift andmoment were modeled with the quasi-steady approximationCubic nonlinearities were introduced for the plunge andpitch Complex motions were predicted under the combinedexcitations by analytical solutions based on the normal formmethod which were validated by numerical integrations Ina subsequent study Bibo and Daqaq [68] performed exper-iment to demonstrate these complex motions by attachingthe harvester prototype to a seismic shaker which providedthe harmonic base excitation and putting the whole systemin a wind tunnel which provided the aerodynamic loadsBelow the flutter speed it was found that the flow serves toamplify the output power from base excitations Beyond theflutter speed the power was enhanced when the excitationfrequency was right above resonance while it dropped whenthe excitation frequency was slightly below resonance It wasconcluded that the harvester under combined excitationswas superior to that under one type of excitation Theoutput power was improved by over three times compared tothat from an aeroelastic harvester and a vibration harvestertogether

Bae and Inman [124] analyzed the performance of anairfoil-based piezoaeroelastic energy harvester with the root-locus method and time-integration method It was foundthat energy can be harvested from stable LCOs when thefrequency ratio was larger than 10 in a wide range of windspeeds below the flutter speed for free play nonlinearity andover the flutter speed for cubic hardening nonlinearity

Wu and his coworkers [125] (Xiang et al 2015) the-oretically investigated the performance of an airfoil-basedpiezoaeroelastic energy harvester with free play nonlinearityand showed that the amplitudes of pitch and plunge motionsas well as output power increased with the free play gapwith the power and the gap having an approximate linearrelationship in particularMoreover it was found that discretegusts in the incoming flows influenced the phase of thedynamic and electrical responses yet they had no influenceon the electrical output amplitude For other studies of windenergy harvesting from flapping foils readers are referred tothe excellent review work of Young et al [30] and Xiao andZhu [20] in which the authors inspected flapping foil powerextraction from amathematical aeroelastic perspective with adifferent literature coverage from that of this paper They arerecommended to readers as complementary materials withthe reviews in this section

Different from the utilization of airfoils attached tocantilever tips Kwon [69] experimentally investigated theperformance of a T-shaped piezoelectric cantilevered energy

harvester The T-shape resembled a half H-sectional shapeof the Tacoma Narrow Bridge which collapsed in 1940 dueto large amplitude aeroelastic flutter The T-shape cantileverunderwent coupled bending and torsional motions in windflows Using a prototype with 119871 times 119861 times119867 = 100 times 60 times 30mma 02mm thick aluminum substrate and six attached PZTpatches of 28 times 14mm for each a flutter speed of 4ms and amaximum power of 40mW at a wind speed of 15ms weremeasured with a load of 4MΩ Annual output energy of43Wh was calculated at an assumed mean wind speed of5ms It was concluded that it had the potential to power amobile electronic apparatus cost-effectively with a series ofthe proposed harvesters

Subsequently Park et al [70] continued the study of T-shaped cantilever where electromagnetic transduction wasemployed It was found experimentally that the onset of theharvester occurred only when the load resistance surpasseda certain value that is the flutter onset resistance CFDsimulations were performed to estimate the aerodynamicdamping and thus predict the flutter onset resistance whichagreed well with experiment Using a prototype of 42 times30 times 20mm with a 01016mm thick cantilever substrate amaximum power of around 11mW was delivered to a 1 kΩload at a wind speed of 8ms

Modal convergence flutter based energy harvester designsalso include the work of Boragno et al [126] In their designa wing was attached to a support by two elastomers withone for each side which provided bending and torsionalstiffness at the same time Influences of parameters includingthe elastomer elastic constant wing mass position of masscenter and elastic attachment point on oscillation responseswere investigated The self-sustained oscillations with prop-erly adjusted parameters were concluded to be suitable forenergy harvesting purpose though no specific transductionmechanism was proposed A similar device called flutter millhas been demonstrated by Sharp [109] with electromagnetictransduction

242 Energy Harvesters Based on Cross-Flow Flutter Inspi-red by the natural flapping leaves in the tree subject to ambi-ent flows Li and Lipson [127] proposed a device consisting ofa PVDF stalk a plastic hinge and a triangular polymerplasticldquoleafrdquo Two configurations were investigated with differentdirection arrangements of the stalk that is the horizontal-stalk leaf and the vertical-stalk leaf The horizontal-stalkunderwent bending motion while the leaf underwent cou-pled bending and torsional motions around the hinge thatis modal convergence flutter similar to the airfoil-basedpiezoaeroelastic energy harvester The vertical-stalk wherethe long axes of the stalk were perpendicular to the incomingflow underwent cross-flow flutter which was demonstratedmore clearly in a subsequent study of Li et al [71] with moreexperiments performed It was found that compared to theparallel configuration the cross-flow configuration increasedthe power by one order of magnitude Performances ofdifferent leaf rsquos shapes different leaf rsquos area different stalkscales (short long and narrow-short) and different PVDFlayer configurations (single-layer adhered double-layer andair-spaced double-layer) were measured and compared It


was found that the circle square and equilateral triangleshapes of leaf had similar and the best performance and thecut-in wind speed and peak power increased with leaf rsquos areaStalk scale and PVDF layer configuration affected the powerwith a nonmonotonous complex behavior A peak power of615 120583W was obtained with an adhered double-layer stalk of72 times 16 times 041mm at 8ms on a 5MΩ load and the maximumpower density of 2036120583Wm3 was obtained with a unimorphnarrow-short stalk of 41 times 8 times 0205mm at 7ms on a 30MΩload It was concluded that although the proposed device hadlow-power density compared to commercial wind turbinesit owned advantages of being robust simple miniature sizedand able to blend in urban and natural environments

Analyses of flapping-leaf energy harvesters were also per-formed by McCarthy et al [128 129] with smoke-flow visu-alization and tandem harvester arrangements and coauthorsDeivasigamani et al [72] with a parallel-flow asymmetricconfiguration where the offset of the leaf axes from thestalk axes induced torsional motions of stalk around axis xIt is actually a modal convergence flutter based harvesteryet due to the similar constructions to those by Li andLipson [127] we put its reviews in this section of cross-flowflutter The PVDF partly operated in the d32 mode whichhad a low piezoelectric conversion coefficient therefore itwas concluded that power from torsion (d32) in parallelflow configuration acted only as a low-value peripheralsupplement to that from bending The output was similar tothat of a parallel flowflapping-leaf harvestermuch lower thanthat of a cross-flow counterpart harvester

Studies on energy harvesting from cross-flow flutter werealso conducted by De Marqui Jr et al [106 130] aiming atharvesting energy with the wings of unmanned air vehicles(UAVs) Using an electromechanically coupled finite element(FE)model a preliminary studywas performedbyDeMarquiJr et al [131] on a plate with embedded piezoceramics underbase excitations with no air flows Subsequently aerodynamicloads were introduced to the plate to simulate the conditionduring flight by De Marqui Jr et al [130] using coupledFE model and unsteady vortex-lattice model to predict theelectric outputs In a later study of De Marqui Jr et al[106] segmented electrodes were used to avoid cancelationof electrical output during typical coupled bending-torsionaeroelastic modes It was found that the peak power from thesegmented electrodewas larger than that from the continuouselectrode for all considered load resistance at a flutter speedof 40ms Torsional motions of the coupled modes werefound to become relatively significant for segmented elec-trodes associated with improved broadband performanceand increased flutter speed

Cross-flow flutter based energy harvesters also includethe patented windbelt that was produced by HumdingerWind Energy LLC [108] which extracts wind energy usingelectromagnetic transduction with a properly tensioned flex-ible belt undergoing flutter motions when subjected to flows

243 Energy Harvesters Based on Dual Cantilever FlutterFinally a novel type of flutter termed ldquodual cantilever flutterrdquodifferent from the above-mentioned cases was reported andanalyzed for energy harvesting purpose by Hobeck et al [73]

Two identical cantilevers were found to undergo largeamplitude and persistent vibrations when subject to windflows which can be utilized for energy harvesting purposeTwo identical cantilevers of 146 times 254 times 00254 cm3 wereemployed in the wind tunnel experiment setup The gapdistance was found to affect the power output significantlyFor small gap distances between 025 cm and 10 cm the can-tilevers produced a significant amount of power over a verylarge range of wind speeds from 3ms to 15ms A maximumpower of 0796mw was achieved at 13ms It was concludedthat dual cantilever flutter phenomenon is an attractive androbust energy harvesting method for highly unsteady flowsA comparison of the reported flutter harvesters is presentedin Table 5 with regard to their quantitative performance aswell as the merits demerits and applicability

25 Energy Harvesters Based on Wake Galloping Windenergy extraction exploiting wake galloping phenomenonwas studied by Jung and Lee [27] They developed a deviceconsisting of two paralleled cylinders to extract power fromthe leeward cylinder which oscillated due to the wakes fromthe windward cylinder Electromagnetic transduction wasemployed It was found that with proper distance (4-5 timesthe cylinder diameter) between the parallel cylinders theleeward cylinder could oscillate with considerable magni-tude With two cylinders of 5 cm in diameter and 085m inlength with a space of 25 cm in between an average outputpower of 50ndash370mW was measured under a wind speedof 25ndash45ms with different coil and spring configurationsPiezoelectric energy harvesting could also utilize the wakegallopingwith proper arrangement of parallel cylinders basedon these results

Abdelkefi et al [74] enhanced the performance of agalloping energy harvester with the wake galloping phe-nomenon by placing a circular cylinder in the windwarddirection of a square galloping cylinder It was found exper-imentally that the range of wind speeds for effective energyharvesting can bewidened by thewake effects of the upstreamcylinder With an upstream cylinder 2715 cm in length and125 cm in diameter the power from the square cylinderwas greatly enhanced when the spacing was larger than16 cm especially from 258ms to 351ms where the singlesquare cylinder generated no power without the introducedwake galloping effects With a spacing distance of 24 cm apeak power of 40sim50 120583W was measure at 305ms It wasconcluded that enhanced galloping energy harvesters can bedesigned by utilizing wake galloping effects with properlydesigned dimension spacing distance and load resistanceTable 6 summarizes the reported harvesters based on wakegalloping

26 Energy Harvesters Based on Turbulence-Induced Vibra-tion A big problem of the above-mentioned harvesters isthat most of them oscillate and generate energy only inlaminar flow conditions which are usually not the case innatural environment where turbulence exists thus stabilizingthe harvesters Also they require a cut-in speed as theminimum limit of wind speed below which no power canbe generated Yet turbulence-induced vibrations (TIVs) never


vanish even with very small average wind speed which couldbe utilized by energy harvesters based on TIVs [28 132]

Akaydin et al [47] experimentally investigated the per-formance of a cantilevered harvester placed in turbulentboundary layer flow near the bottom wall of a wind tunnelIt was found that electrical output monotonically increasedwith the wind speed With a boundary layer thickness of 120575 =115mm the global and localmaxima of powerwere observedindependent of wind speed at ℎ = 40mmand 75mm respec-tively which were far away from the maximum turbulentkinetic energy location of around 8mmTime domain signalsof voltage showed that the dominant frequency of 46Hzwas close to the resonance frequency of the beam while thesecondary dominant frequency was around 317Hz near theturbulence frequency of 275Hz leading to the conclusionthat higher frequency excitations due to turbulence existedin TIVs

Hobeck and Inman [28] proposed the concept of harvest-ing energy from highly turbulent flows with ldquopiezoelectricgrassrdquo consisting of an array of generating elements inthe highly turbulent wake of a bluff body or in entirelyturbulent fluid flows A combination technique of electrome-chanical modeling for the structure and statistical modelingfor the turbulent induced forces was proposed which wasthe first documented experimentally validated TIV energyharvesting model Experimentally a peak power output of10mWper cantileverwasmeasured for the four-element har-vester array fabricated with PZT (10160mm times 2540mm times10160 120583msteel substrate attachedwith 4597mm times 2057mmtimes 15240120583m PZT) at a mean wind speed of 115ms and aload of 492 kΩ A peak power of 12 120583W per cantilever wasmeasured at 7ms on a 470MΩ load for the six-elementarray with PVDF (7260mm times 1620mm times 17800 120583m Mylarsubstrate attached with 6200mm times 1200mm times 3000 120583mPiezo film) The main advantage was concluded to be in itsrobustness and survivability due to its inherent redundancysince only minor reduction in total power happened if oneelement was damaged Table 7 presents a comparison of thediscussed harvesters based on turbulence-induced vibration

27 Other Small-Scale Wind Energy Harvester Designs Withdesigns different from the above-mentioned cases recentprogress on energy harvesting from wind flows also includesa damped cantilever pipe carrying flowing fluid [133] aharmonica-type aeroelastic micropower generator [75] atensioned piezoelectric film facing laminar andor turbulentincoming flows [76] a hinged-hinged piezoelectric beamfacing turbulent airflows [134] and a micromachined piezo-electric airflow energy harvester inside aHelmholtz resonator[135]

Bibo et al [75] proposed a harmonica-type micropowergenerator consisting of a cantilever embeddedwithin a cavityPressure from the incoming flow caused deflection of thecantilever generating a small gap which in turn reducedthe flow pressure The periodic fluctuations in the pressureinduced the beam to undergo self-sustained oscillations Itwas found that using optimal chamber volume and decreasedaperturersquos width reduced the cut-in wind speed The optimalload for maximum power did not vary considerably with

the inflow rate With a 58 times 1626 times 038mm piezoelectriccantilever an average power of 55120583W was obtained at anaverage wind speed of 75ms

Ovejas and Cuadras [76] investigated the energy har-vesting performances of a PVDF film generator with threedifferent setup configurations In the bluff body configurationof setup (a) two cylindrical bluff bodies of 05 cm diameterare attached to the PVDF film in the windward directionwith the wind flowing parallel with the surface film while inthe other two configurations with one or two ends fixed thatis setup (b) and (c) the wind flows perpendicularly to thesurface film Experiment showed that the turbulent flow froma hairdryer gave a higher voltage than the laminar flow from awind tunnel did It was explained that the rotational turbulentflow was added to the vortex shedding from the two bluffbodies thus enhancing power generationWith performancecomparison setup (a) outperformed the other two and wasrecommended for energy harvesting A maximum power of02 120583W was measured with a setup (a) film that was 156 cmin length 19 cm in width 40 120583m in thickness and 99 nFin capacitance The power is relatively low compared toother studies To improve the performance future studieswere recommended to optimize the oscillation and resonantfrequency coupling Table 8 presents a comparison of thediscussed other types of small-scale wind energy harvesters

3 Enhancement Techniques Involvedin Small-Scale Wind Energy HarvestingSystems

31 Enhancement with Modified Structural ConfigurationsIn the literature various methods have been proposed toimprove the efficiency of power output for the vibration-based piezoelectric energy harvesters The beam configura-tion can greatly influence the strain distribution throughoutthe harvester resulting in significant difference in powergeneration For example a trapezoidal cantilever harvestercan generate more than twice power than the rectangular one[136]The multimodal techniques can enlarge the bandwidthof operating frequencies of the vibration-based energy har-vesters for example the piezoelectric energy harvester witha dynamic magnifier [137] and the 2DOF energy harvesterwith closed first and second mode frequencies [138 139]With frequency upconversion techniques the low-frequencyambient vibration can be transferred to high frequencyvibrations providing a frequency-robust energy harvestingsolution for the low frequency oscillations [140]

In the area of wind energy harvesting some techniqueshave also been proposed to enhance the power extractionperformance from the mechanical aspects with modifiedstructural designs For example utilizing the frequencyupconversion mechanism Zhao et al [57] used a 2DOF cut-out structurewithmagnetic interaction to enhance the outputpower of a galloping harvester in the low wind speed range

Recently researchers have been employing the base vibra-tory excitation as a supplementary energy source to enhanceenergy harvesting from aerodynamic forces The efforts havebeen devoted to energy harvesting from airfoil aeroelastic


flutter [68 123] VIV [141 142] and galloping [143] Thework of Bibo and Daqaq [68 123] has been reviewedin Section 241 Dai et al [142] numerically investigatedthe responses of a cantilevered VIV harvester under com-bined VIV and base vibrations Using a single piezoelectricenergy harvester under combined excitations was reported toimprove the power compared to using two separate harvesterswhen the wind speed was in the synchronization regionResponses of a fluid-conveying riser under concurrent exci-tations were also studied [141] Numerically it was found thatthe response changed from aperiodic to periodic motionswhen thewind speed approached the synchronization regionIt was stated that increased base acceleration induces a widersynchronization region Energy harvesting from concurrentgalloping and base excitations was numerically investigatedby Yan et al [143] Widened synchronization region was alsofound to occur with increased base acceleration

Stiffness nonlinearity (monostable bistable or tristable)has been frequently introduced to vibration-based energyharvesters in order to broaden the operating bandwidth thusto adapt to environments with broadband or frequency-variant vibrations [144ndash147] (Tang and Yang 2012) Inwind energy harvesting stiffness nonlinearity has also beenemployed instead of broadening bandwidth to reduce thecut-in wind speed and enhance power output Free play orcubic stiffness nonlinearities have been employed by Sousa etal [67] Bae and Inman [124] and Wu et al [125] to enhanceenergy harvesting from airfoil flutterMoreover the influenceof monostable and bistable nonlinearity on galloping energyharvesting has been investigated by Bibo et al [148] It wasshown that the bistable harvester outperforms the monos-table harvester when interwell oscillations are excited

Zhao and Yang [24] reported an easy but quite effectiveway to increase the power extraction efficiency of aeroelasticenergy harvesters by adding a beam stiffener to amplifythe electromechanical coupling as shown in Figure 4 It wastheoretically explained that the beam stiffener increases theslope of the beamrsquos fundamental mode shape and thus worksas an electromechanical coupling magnifier and enhancesthe output power Theoretical analysis showed that thismethod is effective for all three types of harvesters based ongalloping vortex-induced vibration and flutter Comparedto the conventional designs without the beam stiffener theenhanced designs gave dozens of times increase in poweralmost 100 increase in the power extraction efficiencyand comparable or even smaller transverse displacementExperimentally a maximum output power of around 12mWwas measured at 8ms from a galloping harvester prototypewith the beam stiffener much larger than that of around2mW from the conventional counterpart The shortcomingis that the cut-in wind speed was undesirably increased withthe beam stiffener

Other efforts on structural modifications include attach-ing the cylindrical bluff body to the beam instead of sep-arating them to enhance the effects of vortex shedding[23] and adding a movable mass to adjust the resonancefrequency thus broadening the functional wind speed rangeof a harvester based on vortex-induced vibrations [49] whichhave been mentioned in Section 22

Piezoelectrictransducer

Beam stiffenerBluff body


Beam stiffeneryyyyyyy

Wind flows

Substrate

Gallopingenergy

y

L1 L2 L3

x1

x2

x3

harvester

(a)

VIVenergy harvester

Beam stiffenerPiezoelectrictransducer

Cylindrical bluff body

(b)


NACA 0012 airfoil

Flutter energy harvester

Revolute joint

(c)

Figure 4 Configurations of enhanced energy harvesters with thebeam stiffer based on from (a) to (c) galloping VIV and airfoilflutter [24]

32 Enhancement with Sophisticated Interface Circuits In thefield of VPEH many power conditioning circuit techniqueshave been developed to regulate and enhance power transferfrom the piezoelectric materials to the terminal load or stor-age components including the impedance adaptation [149150] synchronized switch harvesting on inductor (SSHI)[151ndash157] synchronous charge extraction (SCE) [155 158ndash160] and energy storage circuits [161 162] However verylimited researches have been reported on the integrationof advanced interfaces with aeroelastic energy harvesters toenhance their power output

Enhancing power generation performance of windenergy harvesters with modified interface circuits has beenconsidered by Taylor et al [43]They implemented a switchedresonant-power converter which was similar to a series SSHIyet without the full wave rectifier in an oscillating piezoelec-tric eel Robbins et al [44] implemented a quasi-resonant rec-tifier in a flappingPVDF (similar to eel) andBryant et al [116]employed an SSDCI circuit with a separate microcontrollerbased peak detection system in an airfoil-based piezoelectricflutter energy harvester De Marqui Jr et al [106] used aresistive-inductive circuit to extract energy from a flutteringbimorph plate under cross-flow condition and showed thatthe power output was enhanced to about 20 times larger thanthe case with a pure resister in the circuit at the short circuitflutter speed and short circuit flutter frequency

Zhao et al [33 58] investigated the feasibility of employ-ing a self-powered SCE interface to enhance the performance


ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL

Differentialvoltage probe

OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n

minus01733904 lowast (23 lowast (0083333333 lowast I(iin) + 0334271228 lowast V(ina inb)) ndash 18 lowast (0083333333 lowast I(iin) + 0334271228 lowast V(ina inb))3)

Vc1

Figure 5 Schematic of self-powered SCE circuit integrated with a galloping piezoelectric energy harvester [33]

of a galloping-based piezoelectric energy harvester as shownin Figure 5 depicting the equivalent circuit model (ECM) ofharvester and the SCE diagram Experimental and theoreticalcomparison of the performance of SCE with a standardcircuit revealed three main advantages of SCE in galloping-based harvesters Firstly SCE eliminates the requirement ofimpedance matching and ensures the flexibility of adjustingthe harvester for practical applications since the outputpower from SCE is independent of electrical load Secondly75 of piezoelectric materials can be saved by the SCEcompared to the standard circuit Thirdly the SCE helpsto alleviate the fatigue problem with a smaller transversedisplacement during harvester operation

Zhao and Yang [25] further proposed the analyticalsolutions of responses of a galloping-based piezoelectricenergy harvester Explicit expressions of power voltage dis-placement amplitude optimal load and electromechanicalcoupling as well as cut-in wind speed for the simple AC stan-dard and SCE circuits were derived which were validatedwith wind tunnel experiments and circuit simulation It wasfound that the three circuits generated the same maximumpower but the SCE achieved it with the smallest couplingvalue Moreover the SCE was found to give the smallestdisplacement and highest cut-in wind speed while thestandard circuit was found to have the largest displacementand lowest cut-in speed It was concluded that the SCE issuitable for the cases with small coupling and relative highwind speeds while the AC and standard circuit are suitablefor large coupling cases With the AC and standard circuitssmall loads are better for cases requiring high current such ascharging batteries and large loads suit the conditions havinghigh threshold voltages Subsequently Zhao et al [59 60]investigated the capability of enhancing power output of agalloping-based piezoelectric energy harvester with the SSHIinterfaces Experimentally it was found that the SSHI circuitachieves tremendous power enhancement in aweak-couplingsystem and the enhancement is more significant at higherwind speeds A power increase of 143 was obtained with

the SSHI at 7ms for a weak-coupling harvester However theSSHI circuits lost the advantage strong-coupling conditions

4 Application of Small-Scale Wind EnergyHarvesting in Self-Powered Wireless Sensors

Many studies in vibration energy harvesting have investigatedthe feasibility of extracting energy from ambient vibrationsto implement self-powered wireless sensors Similarly a mainpurpose of small-scale wind energy harvesting is to power thewireless sensors placed in an airflow-existing environmentwith the extracted flow power

Flammini et al [163] demonstrated the viability ofharvesting small-scale wind energy to power autonomoussensors in air ducts used for heating ventilating and air-conditioning (HVAC) To demonstrate the concept a small-scale wind turbine with a commercial electromagnetic gen-erator and six fan blades of 4 cm were employed as the windenergy harvester The wind turbine was attached with theelectronic circuit consisting of the autonomous sensor andthe readout unit Signals were transmitted through electro-magnetic coupling at 125 kHz between the antenna of thetransponder (U3280M) in the airflow-powered autonomoussensor and the transceiver (U2270B) in the readout unit Itwas shown that the system was able to work at wind speedshigher than 4ms with comparable wind speed predictionsto the readings from a reference flowmeter confirming thefeasibility of powering autonomous sensors for airspeedmonitoring with airflow energy

In a subsequent study Sardini and Serpelloni [164]extended the application of the integrated harvester andsensor to monitor the air temperature A small-scale windturbine consisting of a DC servomotor (1624T1 4G9 Faul-haber) of 32 times 32 times 22mm and two blades of 65mm diameterwas attached with an autonomous sensing system consistingof a microcontroller an integrated temperature sensor and aradio-frequency transmitter The system was able to transmit


Operational amplifier

Signal for sensing

Comparator

Bridge rectifier

Signal for synchronization

Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body

Thin-filmbattery andrechargingcircuit

circuit

GND

DC-DCconvertor

connector

A

Power

LED

s

ATMega128Lmicrocontroller

Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r

Figure 6 Schematic of Trinity indoor sensing system [34]

signal at wind speeds higher than 3ms with a 433-MHzpoint-to-point communication to a receiver placed within 4sim5m distance from the sensor with a time interval of 2 s It wasconcluded that the self-powered wireless sensor harvestingambient airflow energy can be applied in environmentalhealth monitoring applications

Along with the recently increasing desire on indoormicroclimate control Li et al [34] developed the first doc-umented Trinity system that is wind energy harvestingsynchronous duty-cycling and sensing as a self-sustainingsensing system to monitor and control the wind speed atindividual outlets of a HVAC system according to real-time population density The schematic of the Trinity isshown in Figure 6 The energy generated from a galloping-based energy harvester that consisted of a bimorph anda square sectioned bluff body was delivered to the powermanagement module to power the sensor and charge thetwo thin-film batteries (if surplus energy was available) Low-power self-calibration strategy and per-link synchronizationwere implemented for synchronous duty-cycling to ensurethe receivers to wake up in time to receive data packets fromthe respective senders The low duty-cycles (lt042) weredue to the fact that the energy harvested was not sufficientto continuously activate the sensing nodes The wind speedwas inferred by sampling the voltage of the harvester based onthe measured relationship between voltage and wind speedaccomplished with an amplifier circuit consuming a lowpower more than 500 120583WThe Trinity prototype successfullypredicted agreed wind speeds with an anemometer within 3sim6ms at 16 HVAC outlets It was concluded that the Trinity isa successful demonstration of a self-powered indoor sensingsystem given a carefully designed network operation mode

5 Conclusions

This paper reviews the state-of-the-art techniques ofsmall-scale energy harvesting from a quantitative aspect

Miniaturized windmills or wind turbines can generate asignificant amount of power Yet the biggest concern is thatthe rotary components are not desired for long-term use ofsuch small sized devices Besides the windmills and turbinessummaries of various devices based onVIV galloping flutterwake galloping TIV and other types reviewed are presentedin Tables 2ndash8 Their merits limitations applicabilities andother information that the authors feel useful are also given inthe tables It should be noted that each technique investigatedis suitable for a specific condition and has weakness in otherconditions One should choose a suitable technique ordesign according to the specific wind flow conditions likewhether the flow is smooth or turbulent whether the flowspeed is stable or frequently varies and what the dominantwind speed range is and so forth As for the financialconsideration the cost of an energy harvester depends onvarious factors such as the size the transductionmechanismand the type of piezoelectric material used Typically a singlepiece of commercial ready-to-mount piezoelectric sheetcosts around $50sim80 such as the MFC sheet [165] and theDuraAct sheet [166] Prices should go down for purchases inlarge volume Also raw piezoelectric sheets cost much lessfor example the PZT sheet without soldered wires costs lessthan $1cm2 (Piezo Systems Inc) and the raw PVDF costsless than cent1cm2 [167] For designs incorporating magnets a10mm times 5mm neodymium magnet costs as low as $2 [168]yet building a sophisticated rotor for a small turbine shouldinevitably cost much more Increase in size of the harvesterwill usually cost more Considering the ever-reduced powerrequirement of the wireless sensor a harvester in cm scaleis reasonably sufficient to power a sensor unit Moreoverthere are some commercial power management devicesfor convenient integration of energy harvesting moduleand sensor module such as the LTC3330 chip [169] whichcosts $5 With the fast technology development it can beanticipated that a totally self-powered WSN can be built at areasonable cost


The authors hope to provide some useful guidance forresearchers who are interested in small-scale wind energyharvesting and help them build a quantitative understandingWith future efforts in developing integrated self-poweredelectronics like autonomous sensors incorporating windenergy harvesting and sensing techniques the concept ofwind energy harvesting will be finally led to real engineeringapplications

Conflicts of Interest

The authors declare that they have no conflicts of interestregarding the publication of this paper

References

[1] S Roundy P K Wright and J Rabaey ldquoA study of lowlevel vibrations as a power source for wireless sensor nodesrdquoComputer Communications vol 26 no 11 pp 1131ndash1144 2003

[2] P D Mitcheson P Miao B H Stark E M Yeatman A SHolmes and T C Green ldquoMEMS electrostatic micropowergenerator for low frequency operationrdquo Sensors and ActuatorsA Physical vol 115 no 2-3 pp 523ndash529 2004

[3] M El-Hami P Glynne-Jones N M White et al ldquoDesign andfabrication of a new vibration-based electromechanical powergeneratorrdquo Sensors and Actuators A Physical vol 92 no 1-3pp 335ndash342 2001

[4] S P Beeby M J Tudor and N M White ldquoEnergy harvestingvibration sources for microsystems applicationsrdquoMeasurementScience andTechnology vol 17 no 12 article R01 pp R175ndashR1952006

[5] S R Anton and H A Sodano ldquoA review of power harvestingusing piezoelectric materials (2003ndash2006)rdquo Smart Materialsand Structures vol 16 no 3 pp R1ndashR21 2007

[6] A Erturk Electromechanical modeling of piezoelectric energyharvesters [PhD thesis] Virginia Polytechnic Institute and StateUniversity 2009

[7] L Tang Y Yang and C K Soh ldquoToward broadband vibration-based energy harvestingrdquo Journal of Intelligent Material Systemsand Structures vol 21 no 18 pp 1867ndash1897 2010

[8] M A Karami Micro-scale and nonlinear vibrational energyharvesting [PhD thesis] Virginia Polytechnic Institute andState University 2012

[9] Y Wang Simultaneous energy harvesting and vibration controlvia piezoelectric materials [PhD thesis] Virginia PolytechnicInstitute and State University 2012

[10] R L Harne and K W Wang ldquoA review of the recent researchon vibration energy harvesting via bistable systemsrdquo SmartMaterials and Structures vol 22 no 2 Article ID 023001 2013

[11] H S Kim J-H Kim and J Kim ldquoA review of piezoelectricenergy harvesting based on vibrationrdquo International Journal ofPrecision Engineering andManufacturing vol 12 no 6 pp 1129ndash1141 2011

[12] S P Pellegrini N Tolou M Schenk and J L Herder ldquoBistablevibration energy harvesters a reviewrdquo Journal of IntelligentMaterial Systems and Structures vol 24 no 11 pp 1303ndash13122013

[13] M F Daqaq R Masana A Erturk and D D Quinn ldquoOn therole of nonlinearities in vibratory energy harvesting a criticalreview and discussionrdquo Applied Mechanics Reviews vol 66 no4 Article ID 040801 2014

[14] H D Akaydin Piezoelectric energy harvesting from fluid flow[PhD thesis] City University of New York 2012

[15] A Abdelkefi Global nonlinear analysis of piezoelectric energyharvesting from ambient and aeroelastic vibrations [PhD thesis]Virginia Polytechnic Institute and State University 2012

[16] M BryantAeroelastic flutter vibration energy harvesting model-ing testing and system design [PhD thesis] Cornell University2012

[17] J D Hobeck Energy harvesting with piezoelectric grass forautonomous self-sustaining sensor networks [PhD thesis] TheUniversity of Michigan 2014

[18] A Bibo Investigation of concurrent energy harvesting fromambient vibrations and wind [PhD thesis] ClemsonUniversity2014

[19] L Zhao Small-scale wind energy harvesting using piezoelectricmaterials [PhD thesis] Nanyang Technological University2015

[20] Q Xiao and Q Zhu ldquoA review on flow energy harvesters basedon flapping foilsrdquo Journal of Fluids and Structures vol 46 pp174ndash191 2014

[21] J M McCarthy S Watkins A Deivasigamani and S J JohnldquoFluttering energy harvesters in the wind a reviewrdquo Journal ofSound and Vibration vol 361 pp 355ndash377 2016

[22] S Priya C-T Chen D Fye and J Zahnd ldquoPiezoelectricWindmill a novel solution to remote sensingrdquo Japanese Journalof Applied Physics vol 44 pp L104ndashL107 2005

[23] H D Akaydin N Elvin and Y Andreopoulos ldquoThe per-formance of a self-excited fluidic energy harvesterrdquo SmartMaterials and Structures vol 21 no 2 Article ID 025007 2012

[24] L Zhao and Y Yang ldquoEnhanced aeroelastic energy harvestingwith a beam stiffenerrdquo Smart Materials and Structures vol 24no 3 Article ID 032001 2015

[25] L Zhao and Y Yang ldquoAnalytical solutions for galloping-based piezoelectric energy harvesters with various interfacingcircuitsrdquo Smart Materials and Structures vol 24 no 7 ArticleID 075023 2015

[26] M Bryant and E Garcia ldquoModeling and testing of a novelaeroelastic flutter energy harvesterrdquo Journal of Vibration andAcoustics vol 133 no 1 Article ID 011010 2011

[27] H-J Jung and S-W Lee ldquoThe experimental validation of anew energy harvesting system based on the wake gallopingphenomenonrdquo Smart Materials and Structures vol 20 no 5Article ID 055022 2011

[28] J D Hobeck and D J Inman ldquoArtificial piezoelectric grass forenergy harvesting from turbulence-induced vibrationrdquo SmartMaterials and Structures vol 21 no 10 Article ID 105024 2012

[29] A Truitt and S N Mahmoodi ldquoA review on active windenergy harvesting designsrdquo International Journal of PrecisionEngineering and Manufacturing vol 14 no 9 pp 1667ndash16752013

[30] J Young J C S Lai and M F Platzer ldquoA review of progressand challenges in flapping foil power generationrdquo Progress inAerospace Sciences vol 67 pp 2ndash28 2014

[31] A Abdelkefi ldquoAeroelastic energy harvesting a reviewrdquo Interna-tional Journal of Engineering Science vol 100 pp 112ndash135 2016

[32] Y Yang L Zhao and L Tang ldquoComparative study of tipcross-sections for efficient galloping energy harvestingrdquoAppliedPhysics Letters vol 102 no 6 Article ID 064105 2013

[33] L Zhao L Tang and Y Yang ldquoSynchronized charge extractionin galloping piezoelectric energy harvestingrdquo Journal of Intelli-gent Material Systems and Structures vol 27 no 4 pp 453ndash4682016


[34] F Li T Xiang Z Chi et al ldquoPowering indoor sensing withairflows a trinity of energy harvesting synchronous duty-cycling and sensingrdquo in Proceedings of the 11th ACMConferenceon Embedded Networked Sensor Systems (SenSys rsquo13) RomaItaly November 2013

[35] D Rancourt A Tabesh and L G Frechette ldquoEvaluation ofcentimeter-scale micro windmills aerodynamics and electro-magnetic power generationrdquo inProceedings of the PowerMEMSvol 9 pp 93ndash96 2007

[36] D A Howey A Bansal and A S Holmes ldquoDesign andperformance of a centimetre-scale shrouded wind turbine forenergy harvestingrdquo Smart Materials and Structures vol 20 no8 Article ID 085021 2011

[37] S Priya ldquoModeling of electric energy harvesting using piezo-electric windmillrdquoApplied Physics Letters vol 87 no 18 ArticleID 184101 2005

[38] C-T Chen RA Islam and S Priya ldquoElectric energy generatorrdquoIEEE Transactions on Ultrasonics Ferroelectrics and FrequencyControl vol 53 no 3 pp 656ndash661 2006

[39] R Myers M Vickers H Kim and S Priya ldquoSmall scalewindmillrdquo Applied Physics Letters vol 90 no 5 Article ID054106 2007

[40] S Bressers D Avirovik M Lallart D J Inman and S PriyaldquoContact-less wind turbine utilizing piezoelectric bimorphswith magnetic actuationrdquo in Proceedings of the 28th IMAC AConference on Structural Dynamics pp 233ndash243 February 2010

[41] M A Karami J R Farmer and D J Inman ldquoParametricallyexcited nonlinear piezoelectric compact wind turbinerdquo Renew-able Energy vol 50 pp 977ndash987 2013

[42] J J Allen and A J Smits ldquoEnergy harvesting eelrdquo Journal ofFluids and Structures vol 15 no 3-4 pp 629ndash640 2001

[43] G W Taylor J R Burns S M Kammann W B Powers andT R Welsh ldquoThe energy harvesting Eel a small subsurfaceoceanriver power generatorrdquo IEEE Journal of Oceanic Engineer-ing vol 26 no 4 pp 539ndash547 2001

[44] W P Robbins D Morris I Marusic and T O NovakldquoWind-generated electrical energy using flexible piezoelectricmateialsrdquo in Proceedings of the International Mechanical Engi-neering Congress and Exposition (ASME rsquo06) pp 581ndash590Chicago Ill USA November 2006

[45] S Pobering and N Schwesinger ldquoPower supply for wirelesssensor systemsrdquo in Proceedings of the 7th IEEE Conference onSensors pp 685ndash688 Lecce Italy October 2008

[46] S Pobering M Menacher S Ebermaier and N SchwesingerldquoPiezoelectric power conversion with self-induced oscillationrdquoin Proceedings of the PowerMEMS pp 384ndash387 2009

[47] H D Akaydin N Elvin and Y Andreopoulos ldquoEnergy har-vesting from highly unsteady fluid flows using piezoelectricmaterialsrdquo Journal of IntelligentMaterial Systems and Structuresvol 21 no 13 pp 1263ndash1278 2010

[48] H D Akaydın N Elvin and Y Andreopoulos ldquoWake of acylinder a paradigm for energy harvesting with piezoelectricmaterialsrdquo Experiments in Fluids vol 49 no 1 pp 291ndash3042010

[49] L A Weinstein M R Cacan P M So and P K WrightldquoVortex shedding induced energy harvesting from piezoelectricmaterials in heating ventilation and air conditioning flowsrdquoSmartMaterials and Structures vol 21 no 4 Article ID 0450032012

[50] X Gao W-H Shih and W Y Shih ldquoFlow energy harvestingusing piezoelectric cantilevers with cylindrical extensionrdquo IEEE

Transactions on Industrial Electronics vol 60 no 3 pp 1116ndash1118 2013

[51] D-A Wang and H-H Ko ldquoPiezoelectric energy harvestingfrom flow-induced vibrationrdquo Journal of Micromechanics andMicroengineering vol 20 no 2 Article ID 025019 2010

[52] D-A Wang C-Y Chiu and H-T Pham ldquoElectromagneticenergy harvesting from vibrations induced by Karman vortexstreetrdquoMechatronics vol 22 no 6 pp 746ndash756 2012

[53] H-D Tam Nguyen H-T Pham and D-A Wang ldquoA miniaturepneumatic energy generator using Karman vortex streetrdquo Jour-nal of Wind Engineering and Industrial Aerodynamics vol 116pp 40ndash48 2013

[54] J Sirohi and R Mahadik ldquoPiezoelectric wind energy harvesterfor low-power sensorsrdquo Journal of Intelligent Material Systemsand Structures vol 22 no 18 pp 2215ndash2228 2011

[55] J Sirohi and R Mahadik ldquoHarvesting wind energy using a gal-loping piezoelectric beamrdquo Journal of Vibration and Acousticsvol 134 no 1 Article ID 011009 2012

[56] L Zhao L Tang and Y Yang ldquoSmall wind energy harvestingfrom galloping using piezoelectric materialsrdquo in Proceedings ofASME 2012 Conference on Smart Materials Adaptive Structuresand Intelligent Systems (SMASIS rsquo12) pp 919ndash927 NanjingChina 2012

[57] L Zhao L Tang and Y Yang ldquoEnhanced piezoelectric gallop-ing energy harvesting using 2 degree-of-freedom cut-out can-tilever with magnetic interactionrdquo Japanese Journal of AppliedPhysics vol 53 no 6 Article ID 060302 2014

[58] L Zhao L Tang H Wu and Y Yang ldquoSynchronized chargeextraction for aeroelastic energy harvestingrdquo in Active andPassive Smart Structures and Integrated Systems vol 9057 ofProceedings of SPIE San Diego Calif USA March 2014

[59] L Zhao J Liang L Tang Y Yang and H Liu ldquoEnhancementof galloping-based wind energy harvesting by synchronizedswitching interface circuitsrdquo in Proceedings of the SPIE SmartStructures and Materials Nondestructive Evaluation and HealthMonitoring vol 9431 2015

[60] L Zhao L Tang J Liang and Y Yang ldquoSynergy of windenergy harvesting and synchronized switch harvesting interfacecircuitrdquo IEEEASME Transactions on Mechatronics vol PP no99 pp 1ndash1 2016

[61] A Bibo A Abdelkefi and M F Daqaq ldquoModeling and charac-terization of a piezoelectric energy harvester under CombinedAerodynamic and Base Excitationsrdquo ASME Journal of Vibrationand Acoustics vol 137 no 3 Article ID 031017 2015

[62] F Ewere and G Wang ldquoPerformance of galloping piezoelectricenergy harvestersrdquo Journal of Intelligent Material Systems andStructures vol 25 no 14 pp 1693ndash1704 2014

[63] M Bryant and E Garcia ldquoEnergy harvesting a key to wirelesssensor nodesrdquo inProceedings of the 2nd International Conferenceon Smart Materials and Nanotechnology in Engineering vol7493 of Proceedings of SPIE Weihai China July 2009

[64] M Bryant R Tse and E Garcia ldquoInvestigation of host structurecompliance in aeroelastic energy harvestingrdquo in Proceedings ofthe ASME Conference on Smart Materials Adaptive Structuresand Intelligent Systems pp 769ndash775 2012

[65] M Bryant M Pizzonia M Mehallow and E Garcia ldquoEnergyharvesting for self-powered aerostructure actuationrdquo in Pro-ceedings of theActive andPassive Smart Structures and IntegratedSystems 2014 San Diego Calif USA March 2014

[66] A ErturkWGRVieira CDeMarqui Jr andD J Inman ldquoOnthe energy harvesting potential of piezoaeroelastic systemsrdquoApplied Physics Letters vol 96 no 18 Article ID 184103 2010


[67] V Sousa M de Anicezio C De Marqui Jr and A ErturkldquoEnhanced aeroelastic energy harvesting by exploiting com-bined nonlinearities theory and experimentrdquo Smart Materialsand Structures vol 20 no 9 Article ID 094007 2011

[68] A Bibo and M F Daqaq ldquoInvestigation of concurrent energyharvesting from ambient vibrations and wind using a singlepiezoelectric generatorrdquo Applied Physics Letters vol 102 no 24Article ID 243904 2013

[69] S-D Kwon ldquoA T-shaped piezoelectric cantilever for fluidenergy harvestingrdquoApplied Physics Letters vol 97 no 16 ArticleID 164102 2010

[70] J Park G Morgenthal K Kim S-D Kwon and K HLaw ldquoPower evaluation of flutter-based electromagnetic energyharvesters using computational fluid dynamics simulationsrdquoJournal of IntelligentMaterial Systems and Structures vol 25 no14 pp 1800ndash1812 2014

[71] S Li J Yuan and H Lipson ldquoAmbient wind energy harvestingusing cross-flow flutteringrdquo Journal of Applied Physics vol 109no 2 Article ID 026104 2011

[72] A Deivasigamani J M McCarthy S John S Watkins PTrivailo and F Coman ldquoPiezoelectric energy harvesting fromwind using coupled bending-torsional vibrationsrdquo ModernApplied Science vol 8 no 4 pp 106ndash126 2014

[73] J D Hobeck D Geslain and D J Inman ldquoThe dual cantileverflutter phenomenon a novel energy harvesting methodrdquo inSensors and Smart Structures Technologies for Civil MechanicalandAerospace Systems 2014 vol 9061 ofProceedings of SPIE SanDiego Calif USA March 2014

[74] A Abdelkefi J M Scanlon E McDowell and M R HajjldquoPerformance enhancement of piezoelectric energy harvestersfrom wake gallopingrdquo Applied Physics Letters vol 103 no 3Article ID 033903 2013

[75] A Bibo G Li and M F Daqaq ldquoPerformance analysis of aharmonica-type aeroelastic micropower generatorrdquo Journal ofIntelligent Material Systems and Structures vol 23 no 13 pp1461ndash1474 2012

[76] V J Ovejas and A Cuadras ldquoMultimodal piezoelectric windenergy harvestersrdquo Smart Materials and Structures vol 20 no8 Article ID 085030 2011

[77] A Bansal D AHowey andA SHolmes ldquoCM-scale air turbineand generator for energy harvesting from low-speed flowsrdquo inProceedings of the 15th International Conference on Solid-StateSensors Actuators and Microsystems (TRANSDUCERS rsquo09) pp529ndash532 Denver Colo USA June 2009

[78] S Bressers C Vernier J Regan et al ldquoSmall-scale modularwind turbinerdquo in Active and Passive Smart Structures andIntegrated Systems 2010 vol 7643 of Proceedings of SPIE SanDiego Calif USA March 2010

[79] R A Kishore T Coudron and S Priya ldquoSmall-scale windenergy portable turbine (SWEPT)rdquo Journal ofWind Engineeringand Industrial Aerodynamics vol 116 pp 21ndash31 2013

[80] L Gu and C Livermore ldquoImpact-driven frequency up-converting coupled vibration energy harvesting device for lowfrequency operationrdquo Smart Materials and Structures vol 20no 4 Article ID 045004 2011

[81] A Barrero-Gil S Pindado and S Avila ldquoExtracting energyfrom Vortex-Induced Vibrations a parametric studyrdquo AppliedMathematical Modelling vol 36 no 7 pp 3153ndash3160 2012

[82] A Abdelkefi M R Hajj and A H Nayfeh ldquoPhenomenaand modeling of piezoelectric energy harvesting from freelyoscillating cylindersrdquo Nonlinear Dynamics vol 70 no 2 pp1377ndash1388 2012

[83] A Mehmood A Abdelkefi M R Hajj A H Nayfeh I AkhtarandA O Nuhait ldquoPiezoelectric energy harvesting from vortex-induced vibrations of circular cylinderrdquo Journal of Sound andVibration vol 332 no 19 pp 4656ndash4667 2013

[84] D-A Wang H-T Pham C-W Chao and J M Chen ldquoApiezoelectric energy harvester based on pressure fluctuations inKarman Vortex Streetrdquo in Proceedings of the World RenewableEnergy Congress Linkoping Sweden May 2011

[85] O Goushcha N Elvin and Y Andreopoulos ldquoInteractions ofvortices with a flexible beam with applications in fluidic energyharvestingrdquo Applied Physics Letters vol 104 no 2 Article ID021919 2014

[86] J Wang J Ran and Z Zhang ldquoEnergy harvester basedon the synchronization phenomenon of a circular cylinderrdquoMathematical Problems in Engineering vol 2014 Article ID567357 9 pages 2014

[87] Vortex Bladeless Wind Generator httpwwwvortexbladelesscom

[88] A Barrero-Gil G Alonso and A Sanz-Andres ldquoEnergyharvesting from transverse gallopingrdquo Journal of Sound andVibration vol 329 no 14 pp 2873ndash2883 2010

[89] F Sorribes-Palmer and A Sanz-Andres ldquoOptimization ofenergy extraction in transverse gallopingrdquo Journal of Fluids andStructures vol 43 pp 124ndash144 2013

[90] A Abdelkefi M R Hajj and A H Nayfeh ldquoPower harvest-ing from transverse galloping of square cylinderrdquo NonlinearDynamics An International Journal of Nonlinear Dynamics andChaos in Engineering Systems vol 70 no 2 pp 1355ndash1363 2012

[91] A Abdelkefi Z Yan and M R Hajj ldquoPerformance analysisof galloping-based piezoaeroelastic energy harvesters with dif-ferent cross-section geometriesrdquo Journal of Intelligent MaterialSystems and Structures vol 25 no 2 pp 246ndash256 2014

[92] L Zhao L Tang and Y Yang ldquoComparison of modelingmethods and parametric study for a piezoelectric wind energyharvesterrdquo SmartMaterials and Structures vol 22 no 12 ArticleID 125003 2013

[93] A Bibo and M F Daqaq ldquoOn the optimal performance anduniversal design curves of galloping energy harvestersrdquoAppliedPhysics Letters vol 104 no 2 Article ID 023901 2014

[94] A Bibo and M F Daqaq ldquoAn analytical framework for thedesign and comparative analysis of galloping energy harvestersunder quasi-steady aerodynamicsrdquo Smart Materials and Struc-tures vol 24 no 9 Article ID 094006 2015

[95] M F Daqaq ldquoCharacterizing the response of galloping energyharvesters using actual wind statisticsrdquo Journal of Sound andVibration vol 357 pp 365ndash376 2015

[96] F Ewere G Wang and B Cain ldquoExperimental investigationof galloping piezoelectric energy harvesters with square bluffbodiesrdquo Smart Materials and Structures vol 23 no 10 ArticleID 104012 2014

[97] D Vicente-Ludlam A Barrero-Gil andA Velazquez ldquoOptimalelectromagnetic energy extraction from transverse gallopingrdquoJournal of Fluids and Structures vol 51 pp 281ndash291 2014

[98] D Vicente-Ludlam A Barrero-Gil and A VelazquezldquoEnhanced mechanical energy extraction from transversegalloping using a dual mass systemrdquo Journal of Sound andVibration vol 339 pp 290ndash303 2015

[99] L Tang M P Paıdoussis and J Jiang ldquoCantilevered flexibleplates in axial flow energy transfer and the concept of flutter-millrdquo Journal of Sound and Vibration vol 326 no 1-2 pp 263ndash276 2009


[100] J A Dunnmon S C Stanton B P Mann and E H DowellldquoPower extraction from aeroelastic limit cycle oscillationsrdquoJournal of Fluids and Structures vol 27 no 8 pp 1182ndash1198 2011

[101] O Doare and S Michelin ldquoPiezoelectric coupling in energy-harvesting fluttering flexible plates linear stability analysis andconversion efficiencyrdquo Journal of Fluids and Structures vol 27no 8 pp 1357ndash1375 2011

[102] S Michelin and O Doare ldquoEnergy harvesting efficiency ofpiezoelectric flags in axial flowsrdquo Journal of FluidMechanics vol714 pp 489ndash504 2013

[103] X Shan R Song Z Xu andT Xie ldquoDynamic energy harvestingperformance of two Polyvinylidene Fluoride piezoelectric flagsin parallel arrangement in an axial flowrdquo in Proceedings of the15th International Conference on Electronic Packaging Technol-ogy (ICEPT rsquo14) pp 1ndash4 Chengdu China August 2014

[104] D Zhao and E Ega ldquoEnergy harvesting from self-sustainedaeroelastic limit cycle oscillations of rectangular wingsrdquoAppliedPhysics Letters vol 105 no 10 Article ID 103903 2014

[105] Y H Seo B-H Kim and D-S Choi ldquoPiezoelectric micropower harvester using flow-induced vibration for intrastructurehealth monitoring applicationsrdquoMicrosystem Technologies vol21 no 1 pp 169ndash172 2013

[106] C De Marqui Jr W G R Vieira A Erturk and D J InmanldquoModeling and analysis of piezoelectric energy harvesting fromaeroelastic vibrations using the doublet-latticemethodrdquo Journalof Vibration and Acoustics Transactions of the ASME vol 133no 1 Article ID 011003 2011

[107] A Abdelkefi A H Nayfeh and M R Hajj ldquoDesign ofpiezoaeroelastic energy harvestersrdquo Nonlinear Dynamics vol68 no 4 pp 519ndash530 2012

[108] Humdinger Wind Energy Windbelt Innovation httpwwwhumdingerwindcomdocsIDDS_humdinger_techbrief_low-respdf

[109] Flutter mill 2015 httpwwwcreative-scienceorguksharp_fl-utterhtml

[110] P Bade ldquoFlapping-vane wind machinerdquo in Proceedings ofthe International Conference of Appropriate Technologies forSemiarid Areas Wind and Solar Energy for Water Supply pp83ndash88 1976

[111] W McKinney and J DeLaurier ldquoWingmill an oscillating-wingwindmillrdquo Journal of energy vol 5 no 2 pp 109ndash115 1981

[112] V H Schmidt ldquoPiezoelectric wind generatorrdquo PatentUS4536674 A 1985

[113] V H Schmidt ldquoPiezoelectric energy conversion in windmillsrdquoin Proceedings of the IEEE Ultrasonics Symposium pp 897ndash904IEEE 1992

[114] M Bryant E Wolff and E Garcia ldquoParametric design studyof an aeroelastic flutter energy harvesterrdquo in Proceedings of theSPIE Conference on Smart Structures and Materials Active andPassive Smart Structures and Integrated Systems vol 7977 SanDiego Calif USA March 2011

[115] M Bryant M W Shafer and E Garcia ldquoPower and efficiencyanalysis of a flapping wing wind energy harvesterrdquo in Proceed-ings of the Active and Passive Smart Structures and IntegratedSystems vol 8341 of Proceedings of SPIE San Diego Calif USAMarch 2012

[116] M Bryant A D Schlichting and E Garcia ldquoToward efficientaeroelastic energy harvesting device performance comparisonsand improvements through synchronized switchingrdquo in Activeand Passive Smart Structures and Integrated Systems vol 8688of Proceedings of SPIE San Diego Calif USA March 2013

[117] D A Peters S Karunamoorthy and W-M Cao ldquoFinite stateinduced flow models part I two-dimensional thin airfoilrdquoJournal of Aircraft vol 32 no 2 pp 313ndash322 1995

[118] A Erturk O Bilgen M Fontenille and D J Inman ldquoPiezo-electric energy harvesting from macro-fiber composites withan application to morphing-wing aircraftsrdquo in Proceedings ofthe 19th International Conference on Adaptive Structures andTechnologies pp 6ndash9 Ascona Switzerland 2008

[119] C De Marqui and A Erturk ldquoElectroaeroelastic analysis ofairfoil-based wind energy harvesting using piezoelectric trans-duction and electromagnetic inductionrdquo Journal of IntelligentMaterial Systems and Structures vol 24 no 7 pp 846ndash854 2013

[120] J A C Dias C De Marqui Jr and A Erturk ldquoHybridpiezoelectric-inductive flow energy harvesting and dimension-less electroaeroelastic analysis for scalingrdquo Applied PhysicsLetters vol 102 no 4 Article ID 044101 2013

[121] J A C Dias C De Marqui Jr and A Erturk ldquoThree-degree-of-freedom hybrid piezoelectric-inductive aeroelastic energyharvester exploiting a control surfacerdquo AIAA Journal vol 53no 2 pp 394ndash404 2015

[122] A Abdelkefi A H Nayfeh andM R Hajj ldquoModeling and anal-ysis of piezoaeroelastic energy harvestersrdquoNonlinear DynamicsAn International Journal of Nonlinear Dynamics and Chaos inEngineering Systems vol 67 no 2 pp 925ndash939 2012

[123] A Bibo and M F Daqaq ldquoEnergy harvesting under combinedaerodynamic and base excitationsrdquo Journal of Sound and Vibra-tion vol 332 no 20 pp 5086ndash5102 2013

[124] J-S Bae and D J Inman ldquoAeroelastic characteristics of linearand nonlinear piezo-aeroelastic energy harvesterrdquo Journal ofIntelligent Material Systems and Structures vol 25 no 4 pp401ndash416 2014

[125] Y Wu D Li and J Xiang ldquoPerformance analysis and para-metric design of an airfoil-based piezoaeroelastic energy har-vesterrdquo in Proceedings of the 56th AIAAASCEAHSASC Struc-tures Structural Dynamics and Materials Conference 13 pagesKissimmee Fla USA January 2015

[126] C Boragno R Festa and A Mazzino ldquoElastically boundedflapping wing for energy harvestingrdquo Applied Physics Lettersvol 100 no 25 Article ID 253906 2012

[127] S Li and H Lipson ldquoVertical-stalk flapping-leaf generator forwind energy harvestingrdquo in Proceedings of the ASMEConferenceon Smart Materials Adaptive Structures and Intelligent Systems(SMASIS rsquo09) pp 611ndash619 Oxnard Calif USA September 2009

[128] J M McCarthy A Deivasigamani S J John S Watkins FComan and P Petersen ldquoDownstream flow structures of afluttering piezoelectric energy harvesterrdquoExperimentalThermaland Fluid Science vol 51 pp 279ndash290 2013

[129] J M McCarthy A Deivasigamani S Watkins S J John FComan and P Petersen ldquoOn the visualisation of flow struc-tures downstream of fluttering piezoelectric energy harvestersin a tandem configurationrdquo Experimental Thermal and FluidScience vol 57 pp 407ndash419 2014

[130] C De Marqui Jr A Erturk and D J Inman ldquoPiezoaeroelasticmodeling and analysis of a generator wing with continuous andsegmented electrodesrdquo Journal of Intelligent Material Systemsand Structures vol 21 no 10 pp 983ndash993 2010

[131] C De Marqui Jr A Erturk and D J Inman ldquoAn electrome-chanical finite element model for piezoelectric energy harvesterplatesrdquo Journal of Sound and Vibration vol 327 no 1-2 pp 9ndash25 2009

[132] J D Hobeck and D J Inman ldquoA distributed parameter elec-tromechanical and statistical model for energy harvesting from


turbulence-induced vibrationrdquo Smart Materials and Structuresvol 23 no 11 Article ID 115003 2014

[133] N G Elvin and A A Elvin ldquoThe flutter response of apiezoelectrically damped cantilever piperdquo Journal of IntelligentMaterial Systems and Structures vol 20 no 16 pp 2017ndash20262009

[134] C A K Kwuimy G Litak M Borowiec and C NatarajldquoPerformance of a piezoelectric energy harvester driven by airflowrdquo Applied Physics Letters vol 100 no 2 Article ID 0241032012

[135] S P Matova R Elfrink R J M Vullers and R Van SchaijkldquoHarvesting energy from airflowwith amichromachined piezo-electric harvester inside a Helmholtz resonatorrdquo Journal ofMicromechanics andMicroengineering vol 21 no 10 Article ID104001 2011

[136] S Roundy E S Leland J Baker et al ldquoImproving poweroutput for vibration-based energy scavengersrdquo IEEE PervasiveComputing vol 4 no 1 pp 28ndash36 2005

[137] M Arafa W Akl A Aladwani O Aldraihem and A BazldquoExperimental implementation of a cantilevered piezoelectricenergy harvester with a dynamic magnifierrdquo in Proceedings ofthe Active and Passive Smart Structures and Integrated Systemsvol 7977 of Proceedings of SPIE San Diego Calif USA March2011

[138] H Wu L Tang Y Yang and C K Soh ldquoA compact 2 degree-of-freedom energy harvester with cut-out cantilever beamrdquoJapanese Journal of Applied Physics vol 51 no 4 Article ID040211 2012

[139] J E Kim and Y Y Kim ldquoPower enhancing by reversing modesequence in tuned mass-spring unit attached vibration energyharvesterrdquo AIP Advances vol 3 no 7 Article ID 072103 2013

[140] A M Wickenheiser and E Garcia ldquoBroadband vibration-based energy harvesting improvement through frequency up-conversion by magnetic excitationrdquo Smart Materials and Struc-tures vol 19 no 6 Article ID 065020 2010

[141] H L Dai A Abdelkefi and L Wang ldquoModeling and nonlineardynamics of fluid-conveying risers under hybrid excitationsrdquoInternational Journal of Engineering Science vol 81 pp 1ndash142014

[142] H L Dai A Abdelkefi and L Wang ldquoPiezoelectric energyharvesting from concurrent vortex-induced vibrations and baseexcitationsrdquo Nonlinear Dynamics vol 77 no 3 pp 967ndash9812014

[143] Z Yan A Abdelkefi and M R Hajj ldquoPiezoelectric energy har-vesting from hybrid vibrationsrdquo SmartMaterials and Structuresvol 23 no 2 Article ID 025026 2014

[144] F Cottone H Vocca and L Gammaitoni ldquoNonlinear energyharvestingrdquo Physical Review Letters vol 102 no 8 Article ID080601 2009

[145] A Erturk and D J Inman ldquoBroadband piezoelectric powergeneration on high-energy orbits of the bistable Duffing oscil-lator with electromechanical couplingrdquo Journal of Sound andVibration vol 330 no 10 pp 2339ndash2353 2011

[146] S Zhou J Cao A Erturk and J Lin ldquoEnhanced broad-band piezoelectric energy harvesting using rotatable magnetsrdquoApplied Physics Letters vol 102 no 17 Article ID 173901 2013

[147] S Zhou J Cao D J Inman J Lin S Liu and Z Wang ldquoBroa-dband tristable energy harvester modeling and experimentverificationrdquo Applied Energy vol 133 pp 33ndash39 2014

[148] A Bibo A H Alhadidi and M F Daqaq ldquoExploiting anonlinear restoring force to improve the performance of flow

energy harvestersrdquo Journal of Applied Physics vol 117 no 4Article ID 045103 2015

[149] G K Ottman H F Hofmann A C Bhatt and G A LesieutreldquoAdaptive piezoelectric energy harvesting circuit for wirelessremote power supplyrdquo IEEE Transactions on Power Electronicsvol 17 no 5 pp 669ndash676 2002

[150] G K Ottman H F Hofmann and G A Lesieutre ldquoOptimizedpiezoelectric energy harvesting circuit using step-down con-verter in discontinuous conduction moderdquo IEEE Transactionson Power Electronics vol 18 no 2 pp 696ndash703 2003

[151] D Guyomar A Badel E Lefeuvre and C Richard ldquoTowardenergy harvesting using active materials and conversionimprovement by nonlinear processingrdquo IEEE Transactions onUltrasonics Ferroelectrics and Frequency Control vol 52 no 4pp 584ndash594 2005

[152] M Lallart andDGuyomar ldquoAn optimized self-powered switch-ing circuit for non-linear energy harvesting with low voltageoutputrdquo Smart Materials and Structures vol 17 no 3 ArticleID 035030 2008

[153] Y C Shu I C Lien and W J Wu ldquoAn improved analysis ofthe SSHI interface in piezoelectric energy harvestingrdquo SmartMaterials and Structures vol 16 no 6 pp 2253ndash2264 2007

[154] I C Lien Y C Shu W J Wu S M Shiu and H C LinldquoRevisit of series-SSHI with comparisons to other interfacingcircuits in piezoelectric energy harvestingrdquo SmartMaterials andStructures vol 19 no 12 Article ID 125009 2010

[155] E Lefeuvre A Badel C Richard L Petit and D Guyomar ldquoAcomparison between several vibration-powered piezoelectricgenerators for standalone systemsrdquo Sensors and Actuators APhysical vol 126 no 2 pp 405ndash416 2006

[156] J Liang and W-H Liao ldquoAn improved self-powered switchinginterface for piezoelectric energy harvestingrdquo in Proceedings ofthe IEEE International Conference on Information and Automa-tion (ICIA rsquo09) pp 945ndash950 Zhuhai China June 2009

[157] J Liang and W-H Liao ldquoImproved design and analysis of self-powered synchronized switch interface circuit for piezoelectricenergy harvesting systemsrdquo IEEE Transactions on IndustrialElectronics vol 59 no 4 pp 1950ndash1960 2012

[158] E Lefeuvre A Badel C Richard and D Guyomar ldquoPiezoelec-tric energy harvesting device optimization by synchronous elec-tric charge extractionrdquo Journal of Intelligent Material Systemsand Structures vol 16 no 10 pp 865ndash876 2005

[159] E Lefeuvre A Badel C Richard and D Guyomar ldquoEnergyharvesting using piezoelectric materials case of random vibra-tionsrdquo Journal of Electroceramics vol 19 no 4 pp 349ndash3552007

[160] L Tang and Y Yang ldquoAnalysis of synchronized charge extrac-tion for piezoelectric energy harvestingrdquo Smart Materials andStructures vol 20 no 8 Article ID 085022 2011

[161] A M Wickenheiser T Reissman W-J Wu and E GarcialdquoModeling the effects of electromechanical coupling on energystorage through piezoelectric energy harvestingrdquo IEEEASMETransactions on Mechatronics vol 15 no 3 pp 400ndash411 2010

[162] W J Wu A M Wickenheiser T Reissman and E Gar-cia ldquoModeling and experimental verification of synchronizeddischarging techniques for boosting power harvesting frompiezoelectric transducersrdquo Smart Materials and Structures vol18 no 5 Article ID 055012 2009


[163] A Flammini D Marioli E Sardini and M Serpelloni ldquoAnautonomous sensor with energy harvesting capability for air-flow speed measurementsrdquo in Proceedings of the Instrumenta-tion and Measurement Technology Conference (I2MTC rsquo10) pp892ndash897 IEEE Austin Tex USA May 2010

[164] E Sardini and M Serpelloni ldquoSelf-powered wireless sensorfor air temperature and velocity measurements with energyharvesting capabilityrdquo IEEE Transactions on Instrumentationand Measurement vol 60 no 5 pp 1838ndash1844 2011

[165] Smart Material Corp httpwwwsmart-materialcomMFC-product-mainhtml

[166] Physik Instrumente GmbH amp Co KG httpswwwpiceramiccomenproductspiezoceramic-actuatorspatch-transducers

[167] Professional Plastics Inc httpwwwprofessionalplasticscomPVDFFILM

[168] Eclipse Magnetics Ltd httpwwwprofessionalplasticscomPVDFFILM httpwwwnewarkcomeclipse-magneticsn813neodymium-disc-magnets-10mm-xdp74R0104

[169] Linear Technology Corp 2016 httpwwwlinearcomprod-uctLTC3330

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The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

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Chemical EngineeringInternational Journal of Antennas and

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DistributedSensor Networks



this paper is laid on the quantitative comparison betweenthe various fabricated prototypes in the literature regardingtheir dimensions cut-in wind speeds cut-out wind speedspeak power values as well as power densities and so forthbased on which merits weaknesses and applicability ofdifferent designs are discussed in detail The main findingsare summarized in Tables 1-2 and 4ndash8 Moreover besidesthe technique comparison enhancing methods of powerextraction efficiency are reviewed and discussed from twoaspects that is structural modification aspect and interfacecircuit improvement aspect In addition review is conductedon studies about integrating wind energy harvesters withwireless sensors for practical engineering applications Thispaper aims to help researchers from various disciplinesgain quantitative understanding of small-scale wind energyharvesting techniques and provide useful guidance to thosewho want to develop and improve the efficiency of a windenergy harvester

2 Designs of Aeroelastic PiezoelectricEnergy Harvesters

Many designs of small-scale wind energy harvesters havebeen reported in the literature including those in the formof small-scale windmills and turbines and those based onthe aeroelastic instabilities like VIV galloping flutter wake-induced oscillation and TIV In this section performances ofthe recent small-scale wind energy harvester designs will bereviewed and compared

21 Small-Scale Windmill and Wind Turbine Rancourt etal [35] investigated the performance of power generationof a centimeter-scale windmill Power was generated usingelectromagnetic transduction mechanism Three prototypesof propellers were tested in the wind tunnel which wereall 42 cm in diameter with four blades of different pitchangels The experimental results showed that the ldquoSchmitztheoryrdquo which was developed for large scale wind turbine todetermine the optimal tip speed ratio for maximum turbineefficiency (ie kinetic power extracted from thewind over theavailable kinetic flow energy for the area covered by the diskof the propeller) was also valid for small-scale wind turbinesHowever the power generation efficiency (electrical poweroutput over the available kinetic flow energy for the area cov-ered by the disk of the propeller) at low wind speed decreasedsharply due to the friction in the generator and the internalelectric resistance At a high wind speed of 118ms a largepower of 130mW was achieved corresponding to a powergeneration efficiency of 95 while a lower power of 24mWwas obtained at 55ms with a decreased efficiency of 185

Bansal et al [77] and Howey et al [36] tested a miniatureelectromagnetic wind turbine in cm-scale claimed to be thesmallest turbine-based energy harvester reported to datewith a rotor diameter of 2 cm and outer diameter of 32 cmThe turbine [36] consisted of two rotating magnetic ringsmounted on the rim of the rotor and fixed stator coil sand-wiched between themagnetic ringsWind tunnel experimentfound that the cut-in wind speed was 3ms below whichthe turbine could not operate The test was run up to 10ms

and a power of 80 120583W to 43mW was achieved Comparedto the device of Rancourt et al [35] at a low wind speedof 55ms similar power generation efficiency was obtainedthat is 135 for 5ms and 152 for 6ms It was noted thatat wind speeds lower than 7ms the generated power waslimited by bearing loss while at wind speeds higher than7ms power output was limited by resistive generator lossFuture designs of miniature turbines aimed to harvest energyfrom low speed flows should pay attention to these two issues

Both studies of Rancourt et al [35] and Howey et al [36]show that the major challenge of miniature electromagneticwindmill lies in the greatly decreased power generationefficiency in slow flows Of course if a more sophisticatedsmall-scale wind turbine can be established incorporatingoptimized shape of airfoil and proper design of diffuser theoutput power can be significantly increased [78 79] It wasreported by Kishore et al [79] that a properly designed small-scale wind energy portable turbine (SWEPT) with a diameterof 394 cm can generate a power-up to 830mW at a windspeed of 5ms Yet this size of the turbine is much larger thanthose of the small-scale harvesters mentioned above whichare mainly smaller than or in the order of 10 cm

Recently small-scale windmills using piezoelectric trans-duction have shown great potential in efficiently harvestinglow speed flow energy The rotation of the windmill shaftunder wind flows is transferred to oscillatory motion of thepiezoelectric transducer The mechanical transfer is some-times achieved by direct impact between the piezoelectriccantilever and the cam or blade with a working principlesimilar to that of amechanical stopper [80] some other timesit is achieved throughmagnetic interfactionwhere no contactimpact is required

Priya et al [22] proposed a piezoelectric windmill toharvest energy from low speed wind flows Twelve piezo-electric bimorphs were arranged in a circular array aroundthe circumference of the center shaft of the windmill Twelverubber stoppers were connected to the shaft each of whichwas in contact with one of the bimorphsThe shaft connectedvia a cam to a rotating fan was rotated via the camshaftmechanism When the shaft rotated the stoppers causedthe back and forth movements of the bimorph transducersgenerating electrical energy via direct piezoelectric effectThevoltage was measured across a 46 kΩ load at an oscillatoryfrequency of 42Hz Experimentally a standard circuit wasemployed and a power of 102mW after rectification wasobtained at 6Hz and 46 kΩ It was found that powerwas increased with the prestress level and the number ofbimorphs which yet also resulted in increased difficulty inthe fan rotation thus causing an increased cut-in wind speed

In a subsequent work Priya [37] presented a theoreticalmodel based on bending beam theory of bimorphs andequivalent circuit of capacitor to predict the output power ofthe above-mentioned piezoelectric windmill Ten bimorphswere used in the experiment A cut-in wind speed of 47mphand a cut-out wind speed of 12mph (above which damageof structure will occur) were measured A maximum powerof 75mW was obtained after rectification at 10mph across aload of 67 kΩ A linear relationship was given between thesaturated frequency (final constant operating frequency at a


Table1Summaryof

vario

ussm

all-scalewindm

illsa

ndwindturbines

Author

Transductio

nMechanical

transfe

rCu

t-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perswept

area

(mWcm2)

Advantagesdisa

dvantages

Rancou

rtetal

[35]

Electro

magnetic

mdashmdash

mdash130

118

42c

min

dia

938

(i)Highpo

wer

generatio

neffi

ciency

athigh

windspeed

(ii)A

tlow

windspeedeffi

ciency

decreased

sharplydu

etothefric

tionin

theg

enerator


resistance

How

eyetal[36]

Electro

magnetic

mdash3

mdash43

1032c

min

dia

0535

(i)Be


egenerator

loss

limits

them

iniaturiz

ationof

theturbine

Priyae

tal[22]

Piezoelectric

Con

tactvia

mechanical

stopp

ermdash

mdash102

mdash12

bimorph

sinac

ircular

arrayeach

of6times2times

005

cm3

00902

(i)Proves

thefeasib

ilityof

efficiently

harvestin

glowspeedwindenergy

using

piezoelectric

materials

(ii)B

imorph

sare

notvibratin

gin

phases

otheo

utpu

thas

tobe

individu

allyprocessed

Priya[

37]

Piezoelectric

Con

tactvia

mechanical

stopp

er21

54

7545

10bimorph

sinac

ircular

arrayeach

of6times2times

006

cm3

006

63

Chen

etal[38]

Piezoelectric

Con

tactvia

mechanical

stopp

er21

62

1254

508times116times76

2cm3

00134

(i)Ea

syto

fabricate

(ii)S

pace

efficientw

ithar

ectang

ular-array

arrang

emento

ftransdu

cers

(iii)Com

binedcircuitcan

beused

because

allthe

bimorph

sare

vibratingin

phase

(iv)P

ower

was

muchlower

comparedto

thec

ircular

windm

ill

Myersetal[39]

Piezoelectric

Con

tactvia

mechanical

stopp

er24

mdash5

45


m3

00388

(i)Ca

ptured

windenergy

isincreasedby

employingthreefan

blades

Bressersetal

[40]

Piezoelectric

Con

tact-le

ssvia

magnetic

interaction

09

mdash12

40

1651times

1651times

2286c

m3

318times10minus3

(i)Minim

izingthefric

tionallossb

yavoiding

directmechanicalcon

tact

(ii)P

rolong

ingthefatigue

lifeo

fpiezoelectric

elements

(iii)Lo

weringdo

wnthec

ut-in

windspeed

Karamietal[41]

Piezoelectric

Con

tact-le

ssvia

magnetic

interaction

2mdash

410

8times8times175c

m3

00286

(i)Intro

ducing

nonlinearityinto

the

harvester

(ii)U

tilizingbo

thno

nlinearp

aram

etric

excitatio

nandordinary

excitatio

nand

helpingto

achievelow

cut-inwindspeed

high

output

powerand

largeo

peratio

nal

rang

eofw

indspeed


Table2Summaryof

vario

usVIV

energy

harvesterd

evices1

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(lock-in

)(m

s)

Dim

ensio

nsPo

wer

density

per


Advantagesdisa

dvantagesa

ndother

inform

ation

AllenandSm

its[42]

(inwater)

Piezoelectric

Plate

005

(water

speed)

08(w

ater

speed)

mdashmdash

Bluff

bodyfrontal

dimensio

n505

cmamp

381cm

Eelm

embraneleng

th

457cm

amp76

cm


rmed

the

feasibilityof

harvestin

gflu

idenergy

via

VIV

(ii)D

etermines

thatop

timalperfo

rmance

occursatresonancec

onditio

nTaylor

etal[43](in

water)

Piezoelectric

Plate

mdashmdash

3V(peak

voltage)

05(w

ater

speed)

PVDFeel24

cmtimes

76cmtimes150120583

m110(V

cm3)

Robb

inse

tal[44]

Piezoelectric

Cylin

der

mdashmdash

7867

Flapping

PVDF

mem

brane254cmtimes

1778

cmtimes4572120583m

0378

(i)Th

euse

ofwindw

ardbluff

body

and

masso

nthefreee

ndof

thefl

apping

piezoelementcan

enhancee

nergy

conversio

n(ii)E

xperim

entally

proves

theu

seof

quasi-reson

antrectifi

ercanincrease

the

efficiency

byafactoro

f23comparedto

asta

ndardfull-waver

ectifi

er

(iii)Th

eoreticallyconfi

rmsthe

useo

fAFC

MFC

canincrease

thee

fficiency

bya

factor

of25

comparedto

PVDF

Poberin

gand

Schw

esinger[45]

Piezoelectric

Polygon

45

450108

45

Bluff

body

frontal

dimensio

n10

35cm

Th

reeidentical


0035c

m3

00817

(i)Th

euse

ofpiezoelectric

bimorph

cantilevere

nsures

onlythefi

rstm

ode

deform

ationto

guaranteen

ocharge

cancellatio

non

thes

urface

(ii)Th

eoretic

allyprop

oses

theo

ptim

algeom

etry

of119871119863=2125

(iii)Ad

jacent

cantileversarrang

ement

enhances

output

power

Poberin

getal[46

]Piezoelectric

D-shape

15mdash

140

Bluff

body

frontal

dimensio

n10

35cm

Nineidentical


times118times0035c

m3

0164

(i)Ex

perim

entally

valid

ates

theo

ptim

algeom

etry

of119871119863=2125

(ii)U

seof

stapled

piezoelectric

layers

enhanceo

utpu

tpow

er

(iii)Ad

jacent

cantileversarrang

ementcan

furtherlow

erthec

ut-in

windspeeddo

wn

to8m

s

Akaydin

etal[47]

Akaydın

etal[48]

Piezoelectric

Cylin

der

mdashmdash

000

472

3

Bluff

body

3cm

india

12m

inleng

th


002

cm3

472times10minus6

(i)Th

edriv

ingmechanism

oftheb

eamrsquos

oscillatio

nwas

discovered

viaC

FDas

the

combinedeffecto

fthe

overpressure

resulting

from

thes

tagn

ationregion

and

thes

uctio

nof

thec

oreo

fano

ther

vortex

ontheo

pposite

side

(ii)Th

eoptim

alpo

sitionof

theu

pstre

amtip

ofthec

antilever

was

foun

dto

alon

gthe

centerlin

eand

atad

istance

of119909119863=2

(iii)Non

attachmento

fbluffbo

dyand

cantileverresultsin

very

lowou

tput

power


Table2Con

tinued

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(lock-in

)(m

s)

Dim

ensio

nsPo

wer

density

per


Advantagesdisa

dvantagesa

ndother

inform

ation

Akaydin

etal[23]

Piezoelectric

Cylin

der

mdashmdash

01

1192

Bluff

body

198c

min

dia

203cm

inleng

th


00635

cm3

147times10minus3

(i)Attachmento

fthe

cylin

dero

nthe

cantilevertip

anduseo

fPZT

inste

adof

PVDFgreatly

enhanced

theo

utpu

tpow

er

(ii)A

ttachmento

fthe

cylin

dero

nthe

cantilevertip

redu

cesthe

resonancew

ind

speedform

axim

umpo

wer

Weinstein

etal[49]

Piezoelectric

Cylin

der

25(55)

555

Bluff

body

25cm

india

11cm

inleng

th


025

cm3

Who

leplanes

ize225times

11cm2

00918

(i)Operatio

nalw

indspeedrang

eis

broadenedbecausethe

harvesters

resonancefrequ

ency

andits

resonance

windspeedcanbe

tunedby

adjusting

the

positionof

thea

dded

weight

(ii)T

uningmechanism

isno

tautom

atic

Gao

etal[50]

Piezoelectric

Cylin

der

31

mdash003

5(tu

rbulent

flowspeed)

Bluff

body

291cm

india

36c

min

leng

th

Cantilever31times

10times

00202

cm3

125times10minus3

(i)Tu

rbulentfl

owresults

inhigh

erou

tput

power


flow

(ii)T

urbu

lencee

xcitatio

niscla

imed

tobe

thed

ominantd

rivingmechanism

ofthe

harvestervortex

shedding

excitatio

nin

the

lock-in

region

givesa

dd-oncontrib

ution

(iii)Ca

ntilevera

ndcylin

dera

rein

parallel

WangandKo

[51]

Piezoelectric

NA

mdashmdash

2times10minus4

mdashPV


00205

cm3

300times10minus3

(i)Ca

nbe

easilydeployed

inthep

ipelines

tirec

avitiesorm

achinery

byinsta

lling

adiaphragm

onthew

all

(ii)O

utpu

tpow

erisrelativ

elylow

comparedto

otherd

evices

(iii)Metho

dsof

enhancingpo

wer

are

prop

osedfor

exam

pleop

timizingthe

blockage

ratio

adjustin

gthed

iaph

ragm

position

andusingmaterialw

ithhigh

piezoelectric

constants

Wangetal[52]

Electro

magnetic

Trapezoidal

mdashmdash

177times10minus3

138(w

ater

speed)

Bluff

body

425m

mamp

1mm

inbases16

3mm

inheight


1cm3

Coil2c

min

dia

02c

min

thickn

ess

133times10minus3

Tam

Nguyenetal

[53]

Piezoelectric

Triang

lemdash


207

Twoidentic

albluff

bodies0425

cmin

base

leng

th0218cm

inaltitud

ePV


00205

cm3

370times10minus6

1Ifmorethanon

esized

prototypes

wereinvestig

ated

inther

eferencethe

inform

ationof

dimensio

nandcriticalw

indspeeds

listedin

thetablecorrespo

ndstotheo

negiving

maxim

umou

tput

power

lowast1Th

edevicev

olum

eisa

pproximated

with

outcon

sideringthep

iezoelectricelem

entvolum

ethus

thep

ower

density

calculated

isthec

onservativee

stimates

show

ingtheu

pper

boun

d

































Section shape







Table4Summaryof

vario

usgallo

ping

energy

harvesterd

evices

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

per

volume(mWcm3)

Advantagesdisa

dvantagesa

ndother

inform

ation

Sirohi

and

Mahadik[54]

Piezoelectric

Triang

le36

61

5052

Bluff

body

4c

min

side251cm

inleng

th


00635

cm3

0281

(i)Highpeak

power

isachievedw

ithhigh


pling

(ii)V

alidates

thefeasib

ilityof

predictin

ggallo

ping

energy

harvesterrsquos

respon

sewith

quasi-steadyhypo

thesis

(iii)Ab

rupt

decrease

inou

tput

power

at61m

sisun

desired

Sirohi

and

Mahadik[55]

Piezoelectric

D-shape

25

mdash114

47

Bluff

body

3cm

india

235cm

inleng

th

cantilever

9times38times00635

cm3

00134

(i)Outpu

tpow

ercontinuo

uslyincreases

with

windspeedwith

nocut-o

utwind

speed

(ii)W

ideo

peratio

nalw

indspeedrang

e(iii)Re

quiring

turbulentfl

owto

functio

nwellfore

xampleflo

wfro

mar

otatingfan

becauseD

-shape

cann

otself-oscillatein

laminar

flow

(iv)C

antilever

andbluff

body

prism

arein

parallel

Zhao

etal[56]

Yang

etal[32]

Piezoelectric

Square

25

mdash84

80

Bluff

body

4times4times

15cm3

cantilever

15times3times006

cm3

00346

(i)Ex

perim

entally

determ

iningforthe

first

timethatthe

square

sectionisop

timalfor

gallo

ping

energy

harvestin

gcomparedto

othershapesgiving

thelargestpo

wer

and

thelow

estcut-in

windspeed

(ii)H

ighpeak

power

isachievedw

ithhigh


pling

(iii)Wideo

peratio

nalw

indspeedrang

e

Zhao

etal[57]

Piezoelectric

Square

10mdash

450

Bluff

body

4times4times

15cm3

cut-o

utcantileverinner

beam

57times3times

003

cm3

outerb

eam172times66times

006

cm3with

cuto

utat

theinn

erbeam

locatio

n

00162

(i)2D

OFcut-o

utstr

ucture

with

magnetic

interaction

(ii)R

educingthec

ut-in

speed

(iii)En

hancingou

tput

power

inthelow

windspeedrang

e(iv

)Havingstiffn

essn

onlin

earityindu

ced

bymagnetic

interaction

(v)O

utpu

tpow

erislim

itedin

high

wind

speeds

Zhao

andYang

[24]

Piezoelectric

Square

20

mdash12

80

Bluff

body

4times4times

15cm3


006

cm3

beam


05c

m3

00455

(i)Em

ployed

beam

stiffenera

sele

ctromechanicalcou

plingmagnifier

(ii)E

ffectivefor

allthree

typeso

fharvestersbasedon

gallo

ping

vortex-in


tterwith

greatly

enhanced

output

power

(iii)Disp

lacementisn

otincreasedthus

notaggravatin

gfatig

ueprob

lem

(iv)E

asyto

implem

ent

(v)C

ut-in

windspeedisun

desir

ably

increased


Table4Con

tinued

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

per

volume(mWcm3)

Advantagesdisa

dvantagesa

ndother

inform

ation

Zhao

etal[3358]

Piezoelectric

Square

35

mdash114

50

Bluff

body

2times2times

10cm3


006

cm3

00274

(i)Em

ployed

synchron

ousc

harge

extractio

n(SCE

)elim

inates

the

requ

iremento

fimpedancem

atchingand

ensuresthe

flexibilityof

adjusting

the

harvesterfor

practic

alapplications

(ii)S

aving75

ofpiezoelectric

materials

bytheS

CEcomparedto

thes

tand

ard

circuit

(iii)Ac

hievingsm

allertransverse

displacementand

alleviatingfatig

ueprob

lem

with

SCE

Zhao

etal[5960]

Piezoelectric

Square

30

mdash325

70

Bluff

body

2times2times

10cm3


006

cm3

00782

(i)Synchron

ized

switching

harvestin

gon

indu

ctor

(SSH

I)enhances

output

powe

rcomparedto

stand

ardcircuit

(ii)S

SHIsho

wsm

ores

ignificantb

enefits

inweak-coup

lingsyste

msyetloses

benefitsinstr

ong-coup

lingcond

ition

s(iii)Ac

hieving143

power

increase

at7m

s

Bibo

etal[61]

Piezoelectric

Square

asymp22

mdash0348lowast1

45

Bluff

body

508times508times

1016

cm3


003

cm3

00013

(i)Con

currentfl

owandbase

excitatio

nsenhances

energy

harvestin

g(ii)B

asee

xcitatio

nim

proves

electrical

output

inresonancer

egion

(iii)Electricalou

tput

drop

sifb

ase

excitatio

nfre

quency

isclo

seto

buto

utsid

eof

resonancer

egion

Ewerea

ndWang

[62]

Piezoelectric

Square

2mdash

138

Bluff

body

5times5times

10cm3


004

cm3

bumpsto

pgapsiz

e05c

mcon

tactarea127

times4c

m2location

13cm

alon

gcantilever

00512

(i)Incorporatingan

impactbu

mpsto

psuccessfu

llyrelievesthe

fatig

ueprob

lem

(ii)A

chieving

substantial70

redu

ctionin

displacementamplitu

dewith

only20

voltage

redu

ction

lowast1Ca

lculated

by(59V)210

0kΩfro


Table1

andFigure12of

ther

eference


Table5Summaryof

vario

usflu

ttere

nergyharvesterd

evices

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Bryant

and

Garcia[

63]

Bryant

and

Garcia[

26]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoilprofi

leNAC

A0012

186

mdash22

79

Airfoilsemicho

rd297

cmspan136cm

Ca


00381cm3

717times10minus3

(i)Semiempiric

almod

elof

then

onlin

ear


aerodynamicsyste


ctric

alandmechanical

respon

se

(ii)S

uccessfully

predictsthefl

utterb

ound

arywith

oneo

fthe

realpartso

fthe

firsttwoeigenvalues

turningpo

sitivea

ndthetwoim

aginaryparts

coalescing

(iii)Wideo

peratio

nalw

indspeedrang

e(iv

)Sub

criticalH

opfb

ifurcation

alarge

initial

distu

rbance

isfund

amentalfor

syste

msta

rtup

Bryant

etal[64

]Piezoelectric

Mod

alconvergence

flutte

rFlatplate

Stiff

hoststr

ucture

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

Stiff

host

structure

(i)Com

paredto

astiff

hoststr

ucturea

compliant

hoststr

ucture

redu

cesthe

cut-inwindspeed

cut-infre

quency

andoscillatio

nfre

quency

(ii)Th

epeakpo

wer

isshifted

towardthelow

erwindspeeds

with

thec

ompliant

hoststr

ucture

173

2943

26200

Com

pliant

hoststr

ucture

Com

pliant

hoststr

ucture

152

2935

25163

Bryant

etal[65]

Piezoelectric

Mod

alconvergence

flutte

rFlatplate

173

2943

26

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

200

(i)Con

firmsthe

feasibilityof

usingam

bientfl

owenergy

harvestin

gto

power

aerodynamiccontrol

surfa

ces

Erturk

etal[66

]Piezoelectric

Mod

alconvergence

flutte

rAirfoil

930

mdash107

930

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

227times10minus3

(i)Eff

ecto


plingon

flutte

renergy

harvestin

gisanalyzed

(ii)F

ound

thattheo

ptim

alload

gave

the

maxim

umflu

tterspeed

duetothea

ssociated

maxim

umshun

tdam

ping

effectd

uringpo

wer

extractio

n

Sousae

tal[67]

Piezoelectric

Mod

alconvergence

flutte

rAirfoil

Linear

confi

guratio

n

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

Linear

confi

guratio

n255times10minus3

(i)Th

efreep

layno

nlinearityredu

cesthe

cut-in


utpu

tpow

er

(ii)Th

eoreticallydeterm

iningthattheh

ardening

stiffn

essb

rings

ther

espo

nsea

mplitu

deto


theo

peratio

nal

windspeedrang

e

121

mdash12

121

With

freep

layno

nlinearity

With

freep

lay

nonlinearity

100

mdash27

100

573times10minus3

Bibo

andDaqaq

[68]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoil

profi

leNAC

A0012

23

mdash0138lowast1

3(W

ithbase

acceleratio

n015ms2)

Airfoilsemicho

rd42c

mspan52c

m

Cantilevermdash

838times10minus4

(i)Con

currentfl

owandbase

excitatio

nsenhances

power

generatio

nperfo

rmance

(ii)C

oncurrentexcitatio

nsincreaseso

utpu

tpo

wer

by25tim

esbelowthefl

utterspeedand

over

3tim

esabovethe

flutte

rspeed

(iii)Ab

ovethe

flutte

rspeedrequirin

gcareful

adjustm

entb

ecause

power

issensitive

tobase

acceleratio

nfre

quency

Kwon

[69]

Piezoelectric

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

40

15

Flatplatetip60times

30c

m2


002

cm3

256

(i)SimpleT

-shape

structureeasyto

fabricate

(ii)N

orotatin

gcompo

nents

(iii)Wideo

peratio

nalw

indspeedrang

e


Table5Con

tinued

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Park

etal[70]

Electro

magnetic

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

118

Flatplatetip30times

20c

m2


001016c

m3

582


nsetof

theh

arveste

rrequ

iresthe

load


flutte

ron

setresistance

Lietal[71]

Piezoelectric

cross-flo

wflu

tter

mdash4

mdash0615

8adhereddo

uble-la

yer

stalk72times16times

004

1cm3

130

(i)Cr

oss-flo

wconfi

guratio

ngeneratedon

eorder

ofmagnitude

morep

ower

than

thep

arallel

confi

guratio

n(ii)H

avinghigh

power

density

perw

eightand

per

volume

(iii)Be

ingrobu

stsim

pleandminiature

sized

(iv)B

eing

easy

toblendin

urbanandnatural

environm

entsdu

etoits

ldquoleafrdquoa

ppearance

Deivasig

amaniet

al[72]

Piezoelectric

cross-flo

wflu

tter

Triang

lemdash

mdash00883

8

Isoscelestria

ngletip

8c

min

base8

cmin

height035

mm

inthickn

ess

Stalk72times16times

00205

cm3

00651


lkconfi

guratio

nis

superio

rtotheh

orizon

talstalkwith

fivetim

esmoreo

utpu

tpow

er

Hum

ding

erElectro

magnetic

cross-flo

wflu

tter

mdashmdash

mdashasymp9lowast2

10lowast3

Mem

brane12times07c

m2

Casin

g13times3times25c

m3

0923

(i)Successfu

llypo

wersw

irelesssensor

nodes

(ii)B

eing

compactandrobu

st(iii)Lo


peratio

nal

windspeedrang

e

Hob

ecketal[73]

Piezoelectric

Dual

cantilever

flutte

rmdash

asymp3

mdash0796

asymp13

Twoidentic


00254

cm3

0422

(i)Ve

rywideo

peratio

nalw

indspeedrang

ewith

efficientp

ower

generatio

n(ii)G

eneratingas

ignificantamou

ntof

power

from

3msto

15mswhengapissm

all

lowast1Ca

lculated

by18mwgtimes(015

ms298ms2)2

from


thea

utho

rsof

ther

eference


mthefi

gure

inthed


elt(http

wwwhu

mdingerwindcompdfm

icroBe

lt_briefp

df)


Table6Summaryof

vario

uswakeg

alloping

energy

harvesterd

evices

Author

Transductio

nPrism

shape

Cut-in

wind

speed

(ms)

Cut-o

utwind

speed

(ms)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Jung

andLee

[27]

Electro

magnetic

Circular

cylin

der

asymp12

mdash3704

45

Twoidentic

alcylin

ders5

cmin

dia

85cm

inleng

th

Spacingdistance

5times119863=25

cm

0111

(i)Determiningthep

roper

dista

nceb

etweenthep

arallel

cylin

dersforw

akeg

alloping

energy

harvestin

gas

4-5tim

esthec

ylinderd

iameterthatis

119871119863

=4sim

5(ii)H

ighou

tput

power

(iii)Wideo

peratio

nalw

ind

speedrange

(iv)D

evicev

olum

eistoo

big

Abdelkefi

etal[74]

Piezoelectric

Windw

ard

circular

cylin

der

Leew

ard

square

cylin

der

04

mdash004sim005

305

Circular

cylin

der

125c

min

dia

2715

cmin

leng

th

Square

cylin

der

128times12

8times

2667c

m3

Spacingdistance

24cm

Piezoelectric

two

identic


18times00305

cm3

572times10minus4

(i)Po

wer

from

agalloping

square

cylin

derw

asgreatly

enhanced

bywakee

ffectso

fanup

stream

circular

cylin

der

(ii)O

peratio

nalw

indspeed

rangew

aswidened

bywake

gallo

ping

(iii)Diameter

oftheu

pstre

amcylin

dera

ndthes

pacing

distance

betweentwocylin

dersrequ

irecarefuladjustm

ent


Table7Summaryof

vario

usTIVenergy

harvesterd

evices

Author

Transductio

nCu

t-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Akaydin

etal

[47]

Piezoelectric

asymp5lowast1


11

Bluff

body

3cm

india

12m

inleng

th

Cantilever3times16

times002

cm3

Distance

from

the

wall4c

m

648times10minus8

(i)Perfo

rmance

ofharvesterin

turbulentb

ound

arylayer

depend

sonthed

istance

from

the

walldo

minanto

scillation

frequ

ency

was

close

totheb

eam

resonancefrequ

ency

Hob

eckand

Inman

[28]

Piezoelectric

9sim10lowast2

mdash40

115

Bluff

body

445times

445times1092c

m3

Four

identic

alcantileversin

anarray1016

0mmtimes

2540m

mtimes

1016

0120583m

steel

substratea

ttached

with

4597m

mtimes

2057m

mtimes

15240120583m

PZT

00184

(i)Th

efirstT

IVenergy

harvestin

gmod

elwith

experim

entalvalidation

(ii)B

eing

robu

standsurvivable

duetoits

inherent

redu

ndancy

with

minor

redu

ctionin

total

power

caused

byon

edam

aged

elem

ent

(iii)Suitablefor

high

lyturbulent

fluid

flowenvironm

entslik

estr

eamso

rventilationsyste

ms

lowast1Obtainedfro

mtheinformationof

Figure11of

ther

eference

lowast2Obtainedfro

mtheinformationof

Figure7(b)o

fthe

reference



Author Transduction

Cut-inwindspeed(ms)


Maximumpower(mW)

Windspeed at

max power(ms)

Dimensions


(mWcm3)










40120583m

125 times 10minus5



Z

h

dX

(a)

Lp

L tip

Lb

tp tbBp Bb

(b)










Wind

Bluff body

Inner beam

Outer beam

Magnets


Fixed end







h

U

kh

휃

k휃


























































Wind flows

Substrate

Gallopingenergy

y

L1 L2 L3

x1

x2

x3

harvester

(a)

VIVenergy harvester



(b)


NACA 0012 airfoil


Revolute joint

(c)






ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL


OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n


Vc1











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Table1Summaryof

vario

ussm

all-scalewindm

illsa

ndwindturbines

Author

Transductio

nMechanical

transfe

rCu

t-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perswept

area

(mWcm2)

Advantagesdisa

dvantages

Rancou

rtetal

[35]

Electro

magnetic

mdashmdash

mdash130

118

42c

min

dia

938

(i)Highpo

wer

generatio

neffi

ciency

athigh

windspeed

(ii)A

tlow

windspeedeffi

ciency

decreased

sharplydu

etothefric

tionin

theg

enerator


resistance

How

eyetal[36]

Electro

magnetic

mdash3

mdash43

1032c

min

dia

0535

(i)Be


egenerator

loss

limits

them

iniaturiz

ationof

theturbine

Priyae

tal[22]

Piezoelectric

Con

tactvia

mechanical

stopp

ermdash

mdash102

mdash12

bimorph

sinac

ircular

arrayeach

of6times2times

005

cm3

00902

(i)Proves

thefeasib

ilityof

efficiently

harvestin

glowspeedwindenergy

using

piezoelectric

materials

(ii)B

imorph

sare

notvibratin

gin

phases

otheo

utpu

thas

tobe

individu

allyprocessed

Priya[

37]

Piezoelectric

Con

tactvia

mechanical

stopp

er21

54

7545

10bimorph

sinac

ircular

arrayeach

of6times2times

006

cm3

006

63

Chen

etal[38]

Piezoelectric

Con

tactvia

mechanical

stopp

er21

62

1254

508times116times76

2cm3

00134

(i)Ea

syto

fabricate

(ii)S

pace

efficientw

ithar

ectang

ular-array

arrang

emento

ftransdu

cers

(iii)Com

binedcircuitcan

beused

because

allthe

bimorph

sare

vibratingin

phase

(iv)P

ower

was

muchlower

comparedto

thec

ircular

windm

ill

Myersetal[39]

Piezoelectric

Con

tactvia

mechanical

stopp

er24

mdash5

45


m3

00388

(i)Ca

ptured

windenergy

isincreasedby

employingthreefan

blades

Bressersetal

[40]

Piezoelectric

Con

tact-le

ssvia

magnetic

interaction

09

mdash12

40

1651times

1651times

2286c

m3

318times10minus3

(i)Minim

izingthefric

tionallossb

yavoiding

directmechanicalcon

tact

(ii)P

rolong

ingthefatigue

lifeo

fpiezoelectric

elements

(iii)Lo

weringdo

wnthec

ut-in

windspeed

Karamietal[41]

Piezoelectric

Con

tact-le

ssvia

magnetic

interaction

2mdash

410

8times8times175c

m3

00286

(i)Intro

ducing

nonlinearityinto

the

harvester

(ii)U

tilizingbo

thno

nlinearp

aram

etric

excitatio

nandordinary

excitatio

nand

helpingto

achievelow

cut-inwindspeed

high

output

powerand

largeo

peratio

nal

rang

eofw

indspeed


Table2Summaryof

vario

usVIV

energy

harvesterd

evices1

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(lock-in

)(m

s)

Dim

ensio

nsPo

wer

density

per


Advantagesdisa

dvantagesa

ndother

inform

ation

AllenandSm

its[42]

(inwater)

Piezoelectric

Plate

005

(water

speed)

08(w

ater

speed)

mdashmdash

Bluff

bodyfrontal

dimensio

n505

cmamp

381cm

Eelm

embraneleng

th

457cm

amp76

cm


rmed

the

feasibilityof

harvestin

gflu

idenergy

via

VIV

(ii)D

etermines

thatop

timalperfo

rmance

occursatresonancec

onditio

nTaylor

etal[43](in

water)

Piezoelectric

Plate

mdashmdash

3V(peak

voltage)

05(w

ater

speed)

PVDFeel24

cmtimes

76cmtimes150120583

m110(V

cm3)

Robb

inse

tal[44]

Piezoelectric

Cylin

der

mdashmdash

7867

Flapping

PVDF

mem

brane254cmtimes

1778

cmtimes4572120583m

0378

(i)Th

euse

ofwindw

ardbluff

body

and

masso

nthefreee

ndof

thefl

apping

piezoelementcan

enhancee

nergy

conversio

n(ii)E

xperim

entally

proves

theu

seof

quasi-reson

antrectifi

ercanincrease

the

efficiency

byafactoro

f23comparedto

asta

ndardfull-waver

ectifi

er

(iii)Th

eoreticallyconfi

rmsthe

useo

fAFC

MFC

canincrease

thee

fficiency

bya

factor

of25

comparedto

PVDF

Poberin

gand

Schw

esinger[45]

Piezoelectric

Polygon

45

450108

45

Bluff

body

frontal

dimensio

n10

35cm

Th

reeidentical


0035c

m3

00817

(i)Th

euse

ofpiezoelectric

bimorph

cantilevere

nsures

onlythefi

rstm

ode

deform

ationto

guaranteen

ocharge

cancellatio

non

thes

urface

(ii)Th

eoretic

allyprop

oses

theo

ptim

algeom

etry

of119871119863=2125

(iii)Ad

jacent

cantileversarrang

ement

enhances

output

power

Poberin

getal[46

]Piezoelectric

D-shape

15mdash

140

Bluff

body

frontal

dimensio

n10

35cm

Nineidentical


times118times0035c

m3

0164

(i)Ex

perim

entally

valid

ates

theo

ptim

algeom

etry

of119871119863=2125

(ii)U

seof

stapled

piezoelectric

layers

enhanceo

utpu

tpow

er

(iii)Ad

jacent

cantileversarrang

ementcan

furtherlow

erthec

ut-in

windspeeddo

wn

to8m

s

Akaydin

etal[47]

Akaydın

etal[48]

Piezoelectric

Cylin

der

mdashmdash

000

472

3

Bluff

body

3cm

india

12m

inleng

th


002

cm3

472times10minus6

(i)Th

edriv

ingmechanism

oftheb

eamrsquos

oscillatio

nwas

discovered

viaC

FDas

the

combinedeffecto

fthe

overpressure

resulting

from

thes

tagn

ationregion

and

thes

uctio

nof

thec

oreo

fano

ther

vortex

ontheo

pposite

side

(ii)Th

eoptim

alpo

sitionof

theu

pstre

amtip

ofthec

antilever

was

foun

dto

alon

gthe

centerlin

eand

atad

istance

of119909119863=2

(iii)Non

attachmento

fbluffbo

dyand

cantileverresultsin

very

lowou

tput

power


Table2Con

tinued

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(lock-in

)(m

s)

Dim

ensio

nsPo

wer

density

per


Advantagesdisa

dvantagesa

ndother

inform

ation

Akaydin

etal[23]

Piezoelectric

Cylin

der

mdashmdash

01

1192

Bluff

body

198c

min

dia

203cm

inleng

th


00635

cm3

147times10minus3

(i)Attachmento

fthe

cylin

dero

nthe

cantilevertip

anduseo

fPZT

inste

adof

PVDFgreatly

enhanced

theo

utpu

tpow

er

(ii)A

ttachmento

fthe

cylin

dero

nthe

cantilevertip

redu

cesthe

resonancew

ind

speedform

axim

umpo

wer

Weinstein

etal[49]

Piezoelectric

Cylin

der

25(55)

555

Bluff

body

25cm

india

11cm

inleng

th


025

cm3

Who

leplanes

ize225times

11cm2

00918

(i)Operatio

nalw

indspeedrang

eis

broadenedbecausethe

harvesters

resonancefrequ

ency

andits

resonance

windspeedcanbe

tunedby

adjusting

the

positionof

thea

dded

weight

(ii)T

uningmechanism

isno

tautom

atic

Gao

etal[50]

Piezoelectric

Cylin

der

31

mdash003

5(tu

rbulent

flowspeed)

Bluff

body

291cm

india

36c

min

leng

th

Cantilever31times

10times

00202

cm3

125times10minus3

(i)Tu

rbulentfl

owresults

inhigh

erou

tput

power


flow

(ii)T

urbu

lencee

xcitatio

niscla

imed

tobe

thed

ominantd

rivingmechanism

ofthe

harvestervortex

shedding

excitatio

nin

the

lock-in

region

givesa

dd-oncontrib

ution

(iii)Ca

ntilevera

ndcylin

dera

rein

parallel

WangandKo

[51]

Piezoelectric

NA

mdashmdash

2times10minus4

mdashPV


00205

cm3

300times10minus3

(i)Ca

nbe

easilydeployed

inthep

ipelines

tirec

avitiesorm

achinery

byinsta

lling

adiaphragm

onthew

all

(ii)O

utpu

tpow

erisrelativ

elylow

comparedto

otherd

evices

(iii)Metho

dsof

enhancingpo

wer

are

prop

osedfor

exam

pleop

timizingthe

blockage

ratio

adjustin

gthed

iaph

ragm

position

andusingmaterialw

ithhigh

piezoelectric

constants

Wangetal[52]

Electro

magnetic

Trapezoidal

mdashmdash

177times10minus3

138(w

ater

speed)

Bluff

body

425m

mamp

1mm

inbases16

3mm

inheight


1cm3

Coil2c

min

dia

02c

min

thickn

ess

133times10minus3

Tam

Nguyenetal

[53]

Piezoelectric

Triang

lemdash


207

Twoidentic

albluff

bodies0425

cmin

base

leng

th0218cm

inaltitud

ePV


00205

cm3

370times10minus6

1Ifmorethanon

esized

prototypes

wereinvestig

ated

inther

eferencethe

inform

ationof

dimensio

nandcriticalw

indspeeds

listedin

thetablecorrespo

ndstotheo

negiving

maxim

umou

tput

power

lowast1Th

edevicev

olum

eisa

pproximated

with

outcon

sideringthep

iezoelectricelem

entvolum

ethus

thep

ower

density

calculated

isthec

onservativee

stimates

show

ingtheu

pper

boun

d

































Section shape







Table4Summaryof

vario

usgallo

ping

energy

harvesterd

evices

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

per

volume(mWcm3)

Advantagesdisa

dvantagesa

ndother

inform

ation

Sirohi

and

Mahadik[54]

Piezoelectric

Triang

le36

61

5052

Bluff

body

4c

min

side251cm

inleng

th


00635

cm3

0281

(i)Highpeak

power

isachievedw

ithhigh


pling

(ii)V

alidates

thefeasib

ilityof

predictin

ggallo

ping

energy

harvesterrsquos

respon

sewith

quasi-steadyhypo

thesis

(iii)Ab

rupt

decrease

inou

tput

power

at61m

sisun

desired

Sirohi

and

Mahadik[55]

Piezoelectric

D-shape

25

mdash114

47

Bluff

body

3cm

india

235cm

inleng

th

cantilever

9times38times00635

cm3

00134

(i)Outpu

tpow

ercontinuo

uslyincreases

with

windspeedwith

nocut-o

utwind

speed

(ii)W

ideo

peratio

nalw

indspeedrang

e(iii)Re

quiring

turbulentfl

owto

functio

nwellfore

xampleflo

wfro

mar

otatingfan

becauseD

-shape

cann

otself-oscillatein

laminar

flow

(iv)C

antilever

andbluff

body

prism

arein

parallel

Zhao

etal[56]

Yang

etal[32]

Piezoelectric

Square

25

mdash84

80

Bluff

body

4times4times

15cm3

cantilever

15times3times006

cm3

00346

(i)Ex

perim

entally

determ

iningforthe

first

timethatthe

square

sectionisop

timalfor

gallo

ping

energy

harvestin

gcomparedto

othershapesgiving

thelargestpo

wer

and

thelow

estcut-in

windspeed

(ii)H

ighpeak

power

isachievedw

ithhigh


pling

(iii)Wideo

peratio

nalw

indspeedrang

e

Zhao

etal[57]

Piezoelectric

Square

10mdash

450

Bluff

body

4times4times

15cm3

cut-o

utcantileverinner

beam

57times3times

003

cm3

outerb

eam172times66times

006

cm3with

cuto

utat

theinn

erbeam

locatio

n

00162

(i)2D

OFcut-o

utstr

ucture

with

magnetic

interaction

(ii)R

educingthec

ut-in

speed

(iii)En

hancingou

tput

power

inthelow

windspeedrang

e(iv

)Havingstiffn

essn

onlin

earityindu

ced

bymagnetic

interaction

(v)O

utpu

tpow

erislim

itedin

high

wind

speeds

Zhao

andYang

[24]

Piezoelectric

Square

20

mdash12

80

Bluff

body

4times4times

15cm3


006

cm3

beam


05c

m3

00455

(i)Em

ployed

beam

stiffenera

sele

ctromechanicalcou

plingmagnifier

(ii)E

ffectivefor

allthree

typeso

fharvestersbasedon

gallo

ping

vortex-in


tterwith

greatly

enhanced

output

power

(iii)Disp

lacementisn

otincreasedthus

notaggravatin

gfatig

ueprob

lem

(iv)E

asyto

implem

ent

(v)C

ut-in

windspeedisun

desir

ably

increased


Table4Con

tinued

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

per

volume(mWcm3)

Advantagesdisa

dvantagesa

ndother

inform

ation

Zhao

etal[3358]

Piezoelectric

Square

35

mdash114

50

Bluff

body

2times2times

10cm3


006

cm3

00274

(i)Em

ployed

synchron

ousc

harge

extractio

n(SCE

)elim

inates

the

requ

iremento

fimpedancem

atchingand

ensuresthe

flexibilityof

adjusting

the

harvesterfor

practic

alapplications

(ii)S

aving75

ofpiezoelectric

materials

bytheS

CEcomparedto

thes

tand

ard

circuit

(iii)Ac

hievingsm

allertransverse

displacementand

alleviatingfatig

ueprob

lem

with

SCE

Zhao

etal[5960]

Piezoelectric

Square

30

mdash325

70

Bluff

body

2times2times

10cm3


006

cm3

00782

(i)Synchron

ized

switching

harvestin

gon

indu

ctor

(SSH

I)enhances

output

powe

rcomparedto

stand

ardcircuit

(ii)S

SHIsho

wsm

ores

ignificantb

enefits

inweak-coup

lingsyste

msyetloses

benefitsinstr

ong-coup

lingcond

ition

s(iii)Ac

hieving143

power

increase

at7m

s

Bibo

etal[61]

Piezoelectric

Square

asymp22

mdash0348lowast1

45

Bluff

body

508times508times

1016

cm3


003

cm3

00013

(i)Con

currentfl

owandbase

excitatio

nsenhances

energy

harvestin

g(ii)B

asee

xcitatio

nim

proves

electrical

output

inresonancer

egion

(iii)Electricalou

tput

drop

sifb

ase

excitatio

nfre

quency

isclo

seto

buto

utsid

eof

resonancer

egion

Ewerea

ndWang

[62]

Piezoelectric

Square

2mdash

138

Bluff

body

5times5times

10cm3


004

cm3

bumpsto

pgapsiz

e05c

mcon

tactarea127

times4c

m2location

13cm

alon

gcantilever

00512

(i)Incorporatingan

impactbu

mpsto

psuccessfu

llyrelievesthe

fatig

ueprob

lem

(ii)A

chieving

substantial70

redu

ctionin

displacementamplitu

dewith

only20

voltage

redu

ction

lowast1Ca

lculated

by(59V)210

0kΩfro


Table1

andFigure12of

ther

eference


Table5Summaryof

vario

usflu

ttere

nergyharvesterd

evices

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Bryant

and

Garcia[

63]

Bryant

and

Garcia[

26]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoilprofi

leNAC

A0012

186

mdash22

79

Airfoilsemicho

rd297

cmspan136cm

Ca


00381cm3

717times10minus3

(i)Semiempiric

almod

elof

then

onlin

ear


aerodynamicsyste


ctric

alandmechanical

respon

se

(ii)S

uccessfully

predictsthefl

utterb

ound

arywith

oneo

fthe

realpartso

fthe

firsttwoeigenvalues

turningpo

sitivea

ndthetwoim

aginaryparts

coalescing

(iii)Wideo

peratio

nalw

indspeedrang

e(iv

)Sub

criticalH

opfb

ifurcation

alarge

initial

distu

rbance

isfund

amentalfor

syste

msta

rtup

Bryant

etal[64

]Piezoelectric

Mod

alconvergence

flutte

rFlatplate

Stiff

hoststr

ucture

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

Stiff

host

structure

(i)Com

paredto

astiff

hoststr

ucturea

compliant

hoststr

ucture

redu

cesthe

cut-inwindspeed

cut-infre

quency

andoscillatio

nfre

quency

(ii)Th

epeakpo

wer

isshifted

towardthelow

erwindspeeds

with

thec

ompliant

hoststr

ucture

173

2943

26200

Com

pliant

hoststr

ucture

Com

pliant

hoststr

ucture

152

2935

25163

Bryant

etal[65]

Piezoelectric

Mod

alconvergence

flutte

rFlatplate

173

2943

26

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

200

(i)Con

firmsthe

feasibilityof

usingam

bientfl

owenergy

harvestin

gto

power

aerodynamiccontrol

surfa

ces

Erturk

etal[66

]Piezoelectric

Mod

alconvergence

flutte

rAirfoil

930

mdash107

930

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

227times10minus3

(i)Eff

ecto


plingon

flutte

renergy

harvestin

gisanalyzed

(ii)F

ound

thattheo

ptim

alload

gave

the

maxim

umflu

tterspeed

duetothea

ssociated

maxim

umshun

tdam

ping

effectd

uringpo

wer

extractio

n

Sousae

tal[67]

Piezoelectric

Mod

alconvergence

flutte

rAirfoil

Linear

confi

guratio

n

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

Linear

confi

guratio

n255times10minus3

(i)Th

efreep

layno

nlinearityredu

cesthe

cut-in


utpu

tpow

er

(ii)Th

eoreticallydeterm

iningthattheh

ardening

stiffn

essb

rings

ther

espo

nsea

mplitu

deto


theo

peratio

nal

windspeedrang

e

121

mdash12

121

With

freep

layno

nlinearity

With

freep

lay

nonlinearity

100

mdash27

100

573times10minus3

Bibo

andDaqaq

[68]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoil

profi

leNAC

A0012

23

mdash0138lowast1

3(W

ithbase

acceleratio

n015ms2)

Airfoilsemicho

rd42c

mspan52c

m

Cantilevermdash

838times10minus4

(i)Con

currentfl

owandbase

excitatio

nsenhances

power

generatio

nperfo

rmance

(ii)C

oncurrentexcitatio

nsincreaseso

utpu

tpo

wer

by25tim

esbelowthefl

utterspeedand

over

3tim

esabovethe

flutte

rspeed

(iii)Ab

ovethe

flutte

rspeedrequirin

gcareful

adjustm

entb

ecause

power

issensitive

tobase

acceleratio

nfre

quency

Kwon

[69]

Piezoelectric

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

40

15

Flatplatetip60times

30c

m2


002

cm3

256

(i)SimpleT

-shape

structureeasyto

fabricate

(ii)N

orotatin

gcompo

nents

(iii)Wideo

peratio

nalw

indspeedrang

e


Table5Con

tinued

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Park

etal[70]

Electro

magnetic

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

118

Flatplatetip30times

20c

m2


001016c

m3

582


nsetof

theh

arveste

rrequ

iresthe

load


flutte

ron

setresistance

Lietal[71]

Piezoelectric

cross-flo

wflu

tter

mdash4

mdash0615

8adhereddo

uble-la

yer

stalk72times16times

004

1cm3

130

(i)Cr

oss-flo

wconfi

guratio

ngeneratedon

eorder

ofmagnitude

morep

ower

than

thep

arallel

confi

guratio

n(ii)H

avinghigh

power

density

perw

eightand

per

volume

(iii)Be

ingrobu

stsim

pleandminiature

sized

(iv)B

eing

easy

toblendin

urbanandnatural

environm

entsdu

etoits

ldquoleafrdquoa

ppearance

Deivasig

amaniet

al[72]

Piezoelectric

cross-flo

wflu

tter

Triang

lemdash

mdash00883

8

Isoscelestria

ngletip

8c

min

base8

cmin

height035

mm

inthickn

ess

Stalk72times16times

00205

cm3

00651


lkconfi

guratio

nis

superio

rtotheh

orizon

talstalkwith

fivetim

esmoreo

utpu

tpow

er

Hum

ding

erElectro

magnetic

cross-flo

wflu

tter

mdashmdash

mdashasymp9lowast2

10lowast3

Mem

brane12times07c

m2

Casin

g13times3times25c

m3

0923

(i)Successfu

llypo

wersw

irelesssensor

nodes

(ii)B

eing

compactandrobu

st(iii)Lo


peratio

nal

windspeedrang

e

Hob

ecketal[73]

Piezoelectric

Dual

cantilever

flutte

rmdash

asymp3

mdash0796

asymp13

Twoidentic


00254

cm3

0422

(i)Ve

rywideo

peratio

nalw

indspeedrang

ewith

efficientp

ower

generatio

n(ii)G

eneratingas

ignificantamou

ntof

power

from

3msto

15mswhengapissm

all

lowast1Ca

lculated

by18mwgtimes(015

ms298ms2)2

from


thea

utho

rsof

ther

eference


mthefi

gure

inthed


elt(http

wwwhu

mdingerwindcompdfm

icroBe

lt_briefp

df)


Table6Summaryof

vario

uswakeg

alloping

energy

harvesterd

evices

Author

Transductio

nPrism

shape

Cut-in

wind

speed

(ms)

Cut-o

utwind

speed

(ms)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Jung

andLee

[27]

Electro

magnetic

Circular

cylin

der

asymp12

mdash3704

45

Twoidentic

alcylin

ders5

cmin

dia

85cm

inleng

th

Spacingdistance

5times119863=25

cm

0111

(i)Determiningthep

roper

dista

nceb

etweenthep

arallel

cylin

dersforw

akeg

alloping

energy

harvestin

gas

4-5tim

esthec

ylinderd

iameterthatis

119871119863

=4sim

5(ii)H

ighou

tput

power

(iii)Wideo

peratio

nalw

ind

speedrange

(iv)D

evicev

olum

eistoo

big

Abdelkefi

etal[74]

Piezoelectric

Windw

ard

circular

cylin

der

Leew

ard

square

cylin

der

04

mdash004sim005

305

Circular

cylin

der

125c

min

dia

2715

cmin

leng

th

Square

cylin

der

128times12

8times

2667c

m3

Spacingdistance

24cm

Piezoelectric

two

identic


18times00305

cm3

572times10minus4

(i)Po

wer

from

agalloping

square

cylin

derw

asgreatly

enhanced

bywakee

ffectso

fanup

stream

circular

cylin

der

(ii)O

peratio

nalw

indspeed

rangew

aswidened

bywake

gallo

ping

(iii)Diameter

oftheu

pstre

amcylin

dera

ndthes

pacing

distance

betweentwocylin

dersrequ

irecarefuladjustm

ent


Table7Summaryof

vario

usTIVenergy

harvesterd

evices

Author

Transductio

nCu

t-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Akaydin

etal

[47]

Piezoelectric

asymp5lowast1


11

Bluff

body

3cm

india

12m

inleng

th

Cantilever3times16

times002

cm3

Distance

from

the

wall4c

m

648times10minus8

(i)Perfo

rmance

ofharvesterin

turbulentb

ound

arylayer

depend

sonthed

istance

from

the

walldo

minanto

scillation

frequ

ency

was

close

totheb

eam

resonancefrequ

ency

Hob

eckand

Inman

[28]

Piezoelectric

9sim10lowast2

mdash40

115

Bluff

body

445times

445times1092c

m3

Four

identic

alcantileversin

anarray1016

0mmtimes

2540m

mtimes

1016

0120583m

steel

substratea

ttached

with

4597m

mtimes

2057m

mtimes

15240120583m

PZT

00184

(i)Th

efirstT

IVenergy

harvestin

gmod

elwith

experim

entalvalidation

(ii)B

eing

robu

standsurvivable

duetoits

inherent

redu

ndancy

with

minor

redu

ctionin

total

power

caused

byon

edam

aged

elem

ent

(iii)Suitablefor

high

lyturbulent

fluid

flowenvironm

entslik

estr

eamso

rventilationsyste

ms

lowast1Obtainedfro

mtheinformationof

Figure11of

ther

eference

lowast2Obtainedfro

mtheinformationof

Figure7(b)o

fthe

reference



Author Transduction

Cut-inwindspeed(ms)


Maximumpower(mW)

Windspeed at

max power(ms)

Dimensions


(mWcm3)










40120583m

125 times 10minus5



Z

h

dX

(a)

Lp

L tip

Lb

tp tbBp Bb

(b)










Wind

Bluff body

Inner beam

Outer beam

Magnets


Fixed end







h

U

kh

휃

k휃


























































Wind flows

Substrate

Gallopingenergy

y

L1 L2 L3

x1

x2

x3

harvester

(a)

VIVenergy harvester



(b)


NACA 0012 airfoil


Revolute joint

(c)






ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL


OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n


Vc1











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Table2Summaryof

vario

usVIV

energy

harvesterd

evices1

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(lock-in

)(m

s)

Dim

ensio

nsPo

wer

density

per


Advantagesdisa

dvantagesa

ndother

inform

ation

AllenandSm

its[42]

(inwater)

Piezoelectric

Plate

005

(water

speed)

08(w

ater

speed)

mdashmdash

Bluff

bodyfrontal

dimensio

n505

cmamp

381cm

Eelm

embraneleng

th

457cm

amp76

cm


rmed

the

feasibilityof

harvestin

gflu

idenergy

via

VIV

(ii)D

etermines

thatop

timalperfo

rmance

occursatresonancec

onditio

nTaylor

etal[43](in

water)

Piezoelectric

Plate

mdashmdash

3V(peak

voltage)

05(w

ater

speed)

PVDFeel24

cmtimes

76cmtimes150120583

m110(V

cm3)

Robb

inse

tal[44]

Piezoelectric

Cylin

der

mdashmdash

7867

Flapping

PVDF

mem

brane254cmtimes

1778

cmtimes4572120583m

0378

(i)Th

euse

ofwindw

ardbluff

body

and

masso

nthefreee

ndof

thefl

apping

piezoelementcan

enhancee

nergy

conversio

n(ii)E

xperim

entally

proves

theu

seof

quasi-reson

antrectifi

ercanincrease

the

efficiency

byafactoro

f23comparedto

asta

ndardfull-waver

ectifi

er

(iii)Th

eoreticallyconfi

rmsthe

useo

fAFC

MFC

canincrease

thee

fficiency

bya

factor

of25

comparedto

PVDF

Poberin

gand

Schw

esinger[45]

Piezoelectric

Polygon

45

450108

45

Bluff

body

frontal

dimensio

n10

35cm

Th

reeidentical


0035c

m3

00817

(i)Th

euse

ofpiezoelectric

bimorph

cantilevere

nsures

onlythefi

rstm

ode

deform

ationto

guaranteen

ocharge

cancellatio

non

thes

urface

(ii)Th

eoretic

allyprop

oses

theo

ptim

algeom

etry

of119871119863=2125

(iii)Ad

jacent

cantileversarrang

ement

enhances

output

power

Poberin

getal[46

]Piezoelectric

D-shape

15mdash

140

Bluff

body

frontal

dimensio

n10

35cm

Nineidentical


times118times0035c

m3

0164

(i)Ex

perim

entally

valid

ates

theo

ptim

algeom

etry

of119871119863=2125

(ii)U

seof

stapled

piezoelectric

layers

enhanceo

utpu

tpow

er

(iii)Ad

jacent

cantileversarrang

ementcan

furtherlow

erthec

ut-in

windspeeddo

wn

to8m

s

Akaydin

etal[47]

Akaydın

etal[48]

Piezoelectric

Cylin

der

mdashmdash

000

472

3

Bluff

body

3cm

india

12m

inleng

th


002

cm3

472times10minus6

(i)Th

edriv

ingmechanism

oftheb

eamrsquos

oscillatio

nwas

discovered

viaC

FDas

the

combinedeffecto

fthe

overpressure

resulting

from

thes

tagn

ationregion

and

thes

uctio

nof

thec

oreo

fano

ther

vortex

ontheo

pposite

side

(ii)Th

eoptim

alpo

sitionof

theu

pstre

amtip

ofthec

antilever

was

foun

dto

alon

gthe

centerlin

eand

atad

istance

of119909119863=2

(iii)Non

attachmento

fbluffbo

dyand

cantileverresultsin

very

lowou

tput

power


Table2Con

tinued

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(lock-in

)(m

s)

Dim

ensio

nsPo

wer

density

per


Advantagesdisa

dvantagesa

ndother

inform

ation

Akaydin

etal[23]

Piezoelectric

Cylin

der

mdashmdash

01

1192

Bluff

body

198c

min

dia

203cm

inleng

th


00635

cm3

147times10minus3

(i)Attachmento

fthe

cylin

dero

nthe

cantilevertip

anduseo

fPZT

inste

adof

PVDFgreatly

enhanced

theo

utpu

tpow

er

(ii)A

ttachmento

fthe

cylin

dero

nthe

cantilevertip

redu

cesthe

resonancew

ind

speedform

axim

umpo

wer

Weinstein

etal[49]

Piezoelectric

Cylin

der

25(55)

555

Bluff

body

25cm

india

11cm

inleng

th


025

cm3

Who

leplanes

ize225times

11cm2

00918

(i)Operatio

nalw

indspeedrang

eis

broadenedbecausethe

harvesters

resonancefrequ

ency

andits

resonance

windspeedcanbe

tunedby

adjusting

the

positionof

thea

dded

weight

(ii)T

uningmechanism

isno

tautom

atic

Gao

etal[50]

Piezoelectric

Cylin

der

31

mdash003

5(tu

rbulent

flowspeed)

Bluff

body

291cm

india

36c

min

leng

th

Cantilever31times

10times

00202

cm3

125times10minus3

(i)Tu

rbulentfl

owresults

inhigh

erou

tput

power


flow

(ii)T

urbu

lencee

xcitatio

niscla

imed

tobe

thed

ominantd

rivingmechanism

ofthe

harvestervortex

shedding

excitatio

nin

the

lock-in

region

givesa

dd-oncontrib

ution

(iii)Ca

ntilevera

ndcylin

dera

rein

parallel

WangandKo

[51]

Piezoelectric

NA

mdashmdash

2times10minus4

mdashPV


00205

cm3

300times10minus3

(i)Ca

nbe

easilydeployed

inthep

ipelines

tirec

avitiesorm

achinery

byinsta

lling

adiaphragm

onthew

all

(ii)O

utpu

tpow

erisrelativ

elylow

comparedto

otherd

evices

(iii)Metho

dsof

enhancingpo

wer

are

prop

osedfor

exam

pleop

timizingthe

blockage

ratio

adjustin

gthed

iaph

ragm

position

andusingmaterialw

ithhigh

piezoelectric

constants

Wangetal[52]

Electro

magnetic

Trapezoidal

mdashmdash

177times10minus3

138(w

ater

speed)

Bluff

body

425m

mamp

1mm

inbases16

3mm

inheight


1cm3

Coil2c

min

dia

02c

min

thickn

ess

133times10minus3

Tam

Nguyenetal

[53]

Piezoelectric

Triang

lemdash


207

Twoidentic

albluff

bodies0425

cmin

base

leng

th0218cm

inaltitud

ePV


00205

cm3

370times10minus6

1Ifmorethanon

esized

prototypes

wereinvestig

ated

inther

eferencethe

inform

ationof

dimensio

nandcriticalw

indspeeds

listedin

thetablecorrespo

ndstotheo

negiving

maxim

umou

tput

power

lowast1Th

edevicev

olum

eisa

pproximated

with

outcon

sideringthep

iezoelectricelem

entvolum

ethus

thep

ower

density

calculated

isthec

onservativee

stimates

show

ingtheu

pper

boun

d

































Section shape







Table4Summaryof

vario

usgallo

ping

energy

harvesterd

evices

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

per

volume(mWcm3)

Advantagesdisa

dvantagesa

ndother

inform

ation

Sirohi

and

Mahadik[54]

Piezoelectric

Triang

le36

61

5052

Bluff

body

4c

min

side251cm

inleng

th


00635

cm3

0281

(i)Highpeak

power

isachievedw

ithhigh


pling

(ii)V

alidates

thefeasib

ilityof

predictin

ggallo

ping

energy

harvesterrsquos

respon

sewith

quasi-steadyhypo

thesis

(iii)Ab

rupt

decrease

inou

tput

power

at61m

sisun

desired

Sirohi

and

Mahadik[55]

Piezoelectric

D-shape

25

mdash114

47

Bluff

body

3cm

india

235cm

inleng

th

cantilever

9times38times00635

cm3

00134

(i)Outpu

tpow

ercontinuo

uslyincreases

with

windspeedwith

nocut-o

utwind

speed

(ii)W

ideo

peratio

nalw

indspeedrang

e(iii)Re

quiring

turbulentfl

owto

functio

nwellfore

xampleflo

wfro

mar

otatingfan

becauseD

-shape

cann

otself-oscillatein

laminar

flow

(iv)C

antilever

andbluff

body

prism

arein

parallel

Zhao

etal[56]

Yang

etal[32]

Piezoelectric

Square

25

mdash84

80

Bluff

body

4times4times

15cm3

cantilever

15times3times006

cm3

00346

(i)Ex

perim

entally

determ

iningforthe

first

timethatthe

square

sectionisop

timalfor

gallo

ping

energy

harvestin

gcomparedto

othershapesgiving

thelargestpo

wer

and

thelow

estcut-in

windspeed

(ii)H

ighpeak

power

isachievedw

ithhigh


pling

(iii)Wideo

peratio

nalw

indspeedrang

e

Zhao

etal[57]

Piezoelectric

Square

10mdash

450

Bluff

body

4times4times

15cm3

cut-o

utcantileverinner

beam

57times3times

003

cm3

outerb

eam172times66times

006

cm3with

cuto

utat

theinn

erbeam

locatio

n

00162

(i)2D

OFcut-o

utstr

ucture

with

magnetic

interaction

(ii)R

educingthec

ut-in

speed

(iii)En

hancingou

tput

power

inthelow

windspeedrang

e(iv

)Havingstiffn

essn

onlin

earityindu

ced

bymagnetic

interaction

(v)O

utpu

tpow

erislim

itedin

high

wind

speeds

Zhao

andYang

[24]

Piezoelectric

Square

20

mdash12

80

Bluff

body

4times4times

15cm3


006

cm3

beam


05c

m3

00455

(i)Em

ployed

beam

stiffenera

sele

ctromechanicalcou

plingmagnifier

(ii)E

ffectivefor

allthree

typeso

fharvestersbasedon

gallo

ping

vortex-in


tterwith

greatly

enhanced

output

power

(iii)Disp

lacementisn

otincreasedthus

notaggravatin

gfatig

ueprob

lem

(iv)E

asyto

implem

ent

(v)C

ut-in

windspeedisun

desir

ably

increased


Table4Con

tinued

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

per

volume(mWcm3)

Advantagesdisa

dvantagesa

ndother

inform

ation

Zhao

etal[3358]

Piezoelectric

Square

35

mdash114

50

Bluff

body

2times2times

10cm3


006

cm3

00274

(i)Em

ployed

synchron

ousc

harge

extractio

n(SCE

)elim

inates

the

requ

iremento

fimpedancem

atchingand

ensuresthe

flexibilityof

adjusting

the

harvesterfor

practic

alapplications

(ii)S

aving75

ofpiezoelectric

materials

bytheS

CEcomparedto

thes

tand

ard

circuit

(iii)Ac

hievingsm

allertransverse

displacementand

alleviatingfatig

ueprob

lem

with

SCE

Zhao

etal[5960]

Piezoelectric

Square

30

mdash325

70

Bluff

body

2times2times

10cm3


006

cm3

00782

(i)Synchron

ized

switching

harvestin

gon

indu

ctor

(SSH

I)enhances

output

powe

rcomparedto

stand

ardcircuit

(ii)S

SHIsho

wsm

ores

ignificantb

enefits

inweak-coup

lingsyste

msyetloses

benefitsinstr

ong-coup

lingcond

ition

s(iii)Ac

hieving143

power

increase

at7m

s

Bibo

etal[61]

Piezoelectric

Square

asymp22

mdash0348lowast1

45

Bluff

body

508times508times

1016

cm3


003

cm3

00013

(i)Con

currentfl

owandbase

excitatio

nsenhances

energy

harvestin

g(ii)B

asee

xcitatio

nim

proves

electrical

output

inresonancer

egion

(iii)Electricalou

tput

drop

sifb

ase

excitatio

nfre

quency

isclo

seto

buto

utsid

eof

resonancer

egion

Ewerea

ndWang

[62]

Piezoelectric

Square

2mdash

138

Bluff

body

5times5times

10cm3


004

cm3

bumpsto

pgapsiz

e05c

mcon

tactarea127

times4c

m2location

13cm

alon

gcantilever

00512

(i)Incorporatingan

impactbu

mpsto

psuccessfu

llyrelievesthe

fatig

ueprob

lem

(ii)A

chieving

substantial70

redu

ctionin

displacementamplitu

dewith

only20

voltage

redu

ction

lowast1Ca

lculated

by(59V)210

0kΩfro


Table1

andFigure12of

ther

eference


Table5Summaryof

vario

usflu

ttere

nergyharvesterd

evices

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Bryant

and

Garcia[

63]

Bryant

and

Garcia[

26]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoilprofi

leNAC

A0012

186

mdash22

79

Airfoilsemicho

rd297

cmspan136cm

Ca


00381cm3

717times10minus3

(i)Semiempiric

almod

elof

then

onlin

ear


aerodynamicsyste


ctric

alandmechanical

respon

se

(ii)S

uccessfully

predictsthefl

utterb

ound

arywith

oneo

fthe

realpartso

fthe

firsttwoeigenvalues

turningpo

sitivea

ndthetwoim

aginaryparts

coalescing

(iii)Wideo

peratio

nalw

indspeedrang

e(iv

)Sub

criticalH

opfb

ifurcation

alarge

initial

distu

rbance

isfund

amentalfor

syste

msta

rtup

Bryant

etal[64

]Piezoelectric

Mod

alconvergence

flutte

rFlatplate

Stiff

hoststr

ucture

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

Stiff

host

structure

(i)Com

paredto

astiff

hoststr

ucturea

compliant

hoststr

ucture

redu

cesthe

cut-inwindspeed

cut-infre

quency

andoscillatio

nfre

quency

(ii)Th

epeakpo

wer

isshifted

towardthelow

erwindspeeds

with

thec

ompliant

hoststr

ucture

173

2943

26200

Com

pliant

hoststr

ucture

Com

pliant

hoststr

ucture

152

2935

25163

Bryant

etal[65]

Piezoelectric

Mod

alconvergence

flutte

rFlatplate

173

2943

26

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

200

(i)Con

firmsthe

feasibilityof

usingam

bientfl

owenergy

harvestin

gto

power

aerodynamiccontrol

surfa

ces

Erturk

etal[66

]Piezoelectric

Mod

alconvergence

flutte

rAirfoil

930

mdash107

930

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

227times10minus3

(i)Eff

ecto


plingon

flutte

renergy

harvestin

gisanalyzed

(ii)F

ound

thattheo

ptim

alload

gave

the

maxim

umflu

tterspeed

duetothea

ssociated

maxim

umshun

tdam

ping

effectd

uringpo

wer

extractio

n

Sousae

tal[67]

Piezoelectric

Mod

alconvergence

flutte

rAirfoil

Linear

confi

guratio

n

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

Linear

confi

guratio

n255times10minus3

(i)Th

efreep

layno

nlinearityredu

cesthe

cut-in


utpu

tpow

er

(ii)Th

eoreticallydeterm

iningthattheh

ardening

stiffn

essb

rings

ther

espo

nsea

mplitu

deto


theo

peratio

nal

windspeedrang

e

121

mdash12

121

With

freep

layno

nlinearity

With

freep

lay

nonlinearity

100

mdash27

100

573times10minus3

Bibo

andDaqaq

[68]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoil

profi

leNAC

A0012

23

mdash0138lowast1

3(W

ithbase

acceleratio

n015ms2)

Airfoilsemicho

rd42c

mspan52c

m

Cantilevermdash

838times10minus4

(i)Con

currentfl

owandbase

excitatio

nsenhances

power

generatio

nperfo

rmance

(ii)C

oncurrentexcitatio

nsincreaseso

utpu

tpo

wer

by25tim

esbelowthefl

utterspeedand

over

3tim

esabovethe

flutte

rspeed

(iii)Ab

ovethe

flutte

rspeedrequirin

gcareful

adjustm

entb

ecause

power

issensitive

tobase

acceleratio

nfre

quency

Kwon

[69]

Piezoelectric

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

40

15

Flatplatetip60times

30c

m2


002

cm3

256

(i)SimpleT

-shape

structureeasyto

fabricate

(ii)N

orotatin

gcompo

nents

(iii)Wideo

peratio

nalw

indspeedrang

e


Table5Con

tinued

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Park

etal[70]

Electro

magnetic

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

118

Flatplatetip30times

20c

m2


001016c

m3

582


nsetof

theh

arveste

rrequ

iresthe

load


flutte

ron

setresistance

Lietal[71]

Piezoelectric

cross-flo

wflu

tter

mdash4

mdash0615

8adhereddo

uble-la

yer

stalk72times16times

004

1cm3

130

(i)Cr

oss-flo

wconfi

guratio

ngeneratedon

eorder

ofmagnitude

morep

ower

than

thep

arallel

confi

guratio

n(ii)H

avinghigh

power

density

perw

eightand

per

volume

(iii)Be

ingrobu

stsim

pleandminiature

sized

(iv)B

eing

easy

toblendin

urbanandnatural

environm

entsdu

etoits

ldquoleafrdquoa

ppearance

Deivasig

amaniet

al[72]

Piezoelectric

cross-flo

wflu

tter

Triang

lemdash

mdash00883

8

Isoscelestria

ngletip

8c

min

base8

cmin

height035

mm

inthickn

ess

Stalk72times16times

00205

cm3

00651


lkconfi

guratio

nis

superio

rtotheh

orizon

talstalkwith

fivetim

esmoreo

utpu

tpow

er

Hum

ding

erElectro

magnetic

cross-flo

wflu

tter

mdashmdash

mdashasymp9lowast2

10lowast3

Mem

brane12times07c

m2

Casin

g13times3times25c

m3

0923

(i)Successfu

llypo

wersw

irelesssensor

nodes

(ii)B

eing

compactandrobu

st(iii)Lo


peratio

nal

windspeedrang

e

Hob

ecketal[73]

Piezoelectric

Dual

cantilever

flutte

rmdash

asymp3

mdash0796

asymp13

Twoidentic


00254

cm3

0422

(i)Ve

rywideo

peratio

nalw

indspeedrang

ewith

efficientp

ower

generatio

n(ii)G

eneratingas

ignificantamou

ntof

power

from

3msto

15mswhengapissm

all

lowast1Ca

lculated

by18mwgtimes(015

ms298ms2)2

from


thea

utho

rsof

ther

eference


mthefi

gure

inthed


elt(http

wwwhu

mdingerwindcompdfm

icroBe

lt_briefp

df)


Table6Summaryof

vario

uswakeg

alloping

energy

harvesterd

evices

Author

Transductio

nPrism

shape

Cut-in

wind

speed

(ms)

Cut-o

utwind

speed

(ms)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Jung

andLee

[27]

Electro

magnetic

Circular

cylin

der

asymp12

mdash3704

45

Twoidentic

alcylin

ders5

cmin

dia

85cm

inleng

th

Spacingdistance

5times119863=25

cm

0111

(i)Determiningthep

roper

dista

nceb

etweenthep

arallel

cylin

dersforw

akeg

alloping

energy

harvestin

gas

4-5tim

esthec

ylinderd

iameterthatis

119871119863

=4sim

5(ii)H

ighou

tput

power

(iii)Wideo

peratio

nalw

ind

speedrange

(iv)D

evicev

olum

eistoo

big

Abdelkefi

etal[74]

Piezoelectric

Windw

ard

circular

cylin

der

Leew

ard

square

cylin

der

04

mdash004sim005

305

Circular

cylin

der

125c

min

dia

2715

cmin

leng

th

Square

cylin

der

128times12

8times

2667c

m3

Spacingdistance

24cm

Piezoelectric

two

identic


18times00305

cm3

572times10minus4

(i)Po

wer

from

agalloping

square

cylin

derw

asgreatly

enhanced

bywakee

ffectso

fanup

stream

circular

cylin

der

(ii)O

peratio

nalw

indspeed

rangew

aswidened

bywake

gallo

ping

(iii)Diameter

oftheu

pstre

amcylin

dera

ndthes

pacing

distance

betweentwocylin

dersrequ

irecarefuladjustm

ent


Table7Summaryof

vario

usTIVenergy

harvesterd

evices

Author

Transductio

nCu

t-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Akaydin

etal

[47]

Piezoelectric

asymp5lowast1


11

Bluff

body

3cm

india

12m

inleng

th

Cantilever3times16

times002

cm3

Distance

from

the

wall4c

m

648times10minus8

(i)Perfo

rmance

ofharvesterin

turbulentb

ound

arylayer

depend

sonthed

istance

from

the

walldo

minanto

scillation

frequ

ency

was

close

totheb

eam

resonancefrequ

ency

Hob

eckand

Inman

[28]

Piezoelectric

9sim10lowast2

mdash40

115

Bluff

body

445times

445times1092c

m3

Four

identic

alcantileversin

anarray1016

0mmtimes

2540m

mtimes

1016

0120583m

steel

substratea

ttached

with

4597m

mtimes

2057m

mtimes

15240120583m

PZT

00184

(i)Th

efirstT

IVenergy

harvestin

gmod

elwith

experim

entalvalidation

(ii)B

eing

robu

standsurvivable

duetoits

inherent

redu

ndancy

with

minor

redu

ctionin

total

power

caused

byon

edam

aged

elem

ent

(iii)Suitablefor

high

lyturbulent

fluid

flowenvironm

entslik

estr

eamso

rventilationsyste

ms

lowast1Obtainedfro

mtheinformationof

Figure11of

ther

eference

lowast2Obtainedfro

mtheinformationof

Figure7(b)o

fthe

reference



Author Transduction

Cut-inwindspeed(ms)


Maximumpower(mW)

Windspeed at

max power(ms)

Dimensions


(mWcm3)










40120583m

125 times 10minus5



Z

h

dX

(a)

Lp

L tip

Lb

tp tbBp Bb

(b)










Wind

Bluff body

Inner beam

Outer beam

Magnets


Fixed end







h

U

kh

휃

k휃


























































Wind flows

Substrate

Gallopingenergy

y

L1 L2 L3

x1

x2

x3

harvester

(a)

VIVenergy harvester



(b)


NACA 0012 airfoil


Revolute joint

(c)






ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL


OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n


Vc1











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Table2Con

tinued

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(lock-in

)(m

s)

Dim

ensio

nsPo

wer

density

per


Advantagesdisa

dvantagesa

ndother

inform

ation

Akaydin

etal[23]

Piezoelectric

Cylin

der

mdashmdash

01

1192

Bluff

body

198c

min

dia

203cm

inleng

th


00635

cm3

147times10minus3

(i)Attachmento

fthe

cylin

dero

nthe

cantilevertip

anduseo

fPZT

inste

adof

PVDFgreatly

enhanced

theo

utpu

tpow

er

(ii)A

ttachmento

fthe

cylin

dero

nthe

cantilevertip

redu

cesthe

resonancew

ind

speedform

axim

umpo

wer

Weinstein

etal[49]

Piezoelectric

Cylin

der

25(55)

555

Bluff

body

25cm

india

11cm

inleng

th


025

cm3

Who

leplanes

ize225times

11cm2

00918

(i)Operatio

nalw

indspeedrang

eis

broadenedbecausethe

harvesters

resonancefrequ

ency

andits

resonance

windspeedcanbe

tunedby

adjusting

the

positionof

thea

dded

weight

(ii)T

uningmechanism

isno

tautom

atic

Gao

etal[50]

Piezoelectric

Cylin

der

31

mdash003

5(tu

rbulent

flowspeed)

Bluff

body

291cm

india

36c

min

leng

th

Cantilever31times

10times

00202

cm3

125times10minus3

(i)Tu

rbulentfl

owresults

inhigh

erou

tput

power


flow

(ii)T

urbu

lencee

xcitatio

niscla

imed

tobe

thed

ominantd

rivingmechanism

ofthe

harvestervortex

shedding

excitatio

nin

the

lock-in

region

givesa

dd-oncontrib

ution

(iii)Ca

ntilevera

ndcylin

dera

rein

parallel

WangandKo

[51]

Piezoelectric

NA

mdashmdash

2times10minus4

mdashPV


00205

cm3

300times10minus3

(i)Ca

nbe

easilydeployed

inthep

ipelines

tirec

avitiesorm

achinery

byinsta

lling

adiaphragm

onthew

all

(ii)O

utpu

tpow

erisrelativ

elylow

comparedto

otherd

evices

(iii)Metho

dsof

enhancingpo

wer

are

prop

osedfor

exam

pleop

timizingthe

blockage

ratio

adjustin

gthed

iaph

ragm

position

andusingmaterialw

ithhigh

piezoelectric

constants

Wangetal[52]

Electro

magnetic

Trapezoidal

mdashmdash

177times10minus3

138(w

ater

speed)

Bluff

body

425m

mamp

1mm

inbases16

3mm

inheight


1cm3

Coil2c

min

dia

02c

min

thickn

ess

133times10minus3

Tam

Nguyenetal

[53]

Piezoelectric

Triang

lemdash


207

Twoidentic

albluff

bodies0425

cmin

base

leng

th0218cm

inaltitud

ePV


00205

cm3

370times10minus6

1Ifmorethanon

esized

prototypes

wereinvestig

ated

inther

eferencethe

inform

ationof

dimensio

nandcriticalw

indspeeds

listedin

thetablecorrespo

ndstotheo

negiving

maxim

umou

tput

power

lowast1Th

edevicev

olum

eisa

pproximated

with

outcon

sideringthep

iezoelectricelem

entvolum

ethus

thep

ower

density

calculated

isthec

onservativee

stimates

show

ingtheu

pper

boun

d

































Section shape







Table4Summaryof

vario

usgallo

ping

energy

harvesterd

evices

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

per

volume(mWcm3)

Advantagesdisa

dvantagesa

ndother

inform

ation

Sirohi

and

Mahadik[54]

Piezoelectric

Triang

le36

61

5052

Bluff

body

4c

min

side251cm

inleng

th


00635

cm3

0281

(i)Highpeak

power

isachievedw

ithhigh


pling

(ii)V

alidates

thefeasib

ilityof

predictin

ggallo

ping

energy

harvesterrsquos

respon

sewith

quasi-steadyhypo

thesis

(iii)Ab

rupt

decrease

inou

tput

power

at61m

sisun

desired

Sirohi

and

Mahadik[55]

Piezoelectric

D-shape

25

mdash114

47

Bluff

body

3cm

india

235cm

inleng

th

cantilever

9times38times00635

cm3

00134

(i)Outpu

tpow

ercontinuo

uslyincreases

with

windspeedwith

nocut-o

utwind

speed

(ii)W

ideo

peratio

nalw

indspeedrang

e(iii)Re

quiring

turbulentfl

owto

functio

nwellfore

xampleflo

wfro

mar

otatingfan

becauseD

-shape

cann

otself-oscillatein

laminar

flow

(iv)C

antilever

andbluff

body

prism

arein

parallel

Zhao

etal[56]

Yang

etal[32]

Piezoelectric

Square

25

mdash84

80

Bluff

body

4times4times

15cm3

cantilever

15times3times006

cm3

00346

(i)Ex

perim

entally

determ

iningforthe

first

timethatthe

square

sectionisop

timalfor

gallo

ping

energy

harvestin

gcomparedto

othershapesgiving

thelargestpo

wer

and

thelow

estcut-in

windspeed

(ii)H

ighpeak

power

isachievedw

ithhigh


pling

(iii)Wideo

peratio

nalw

indspeedrang

e

Zhao

etal[57]

Piezoelectric

Square

10mdash

450

Bluff

body

4times4times

15cm3

cut-o

utcantileverinner

beam

57times3times

003

cm3

outerb

eam172times66times

006

cm3with

cuto

utat

theinn

erbeam

locatio

n

00162

(i)2D

OFcut-o

utstr

ucture

with

magnetic

interaction

(ii)R

educingthec

ut-in

speed

(iii)En

hancingou

tput

power

inthelow

windspeedrang

e(iv

)Havingstiffn

essn

onlin

earityindu

ced

bymagnetic

interaction

(v)O

utpu

tpow

erislim

itedin

high

wind

speeds

Zhao

andYang

[24]

Piezoelectric

Square

20

mdash12

80

Bluff

body

4times4times

15cm3


006

cm3

beam


05c

m3

00455

(i)Em

ployed

beam

stiffenera

sele

ctromechanicalcou

plingmagnifier

(ii)E

ffectivefor

allthree

typeso

fharvestersbasedon

gallo

ping

vortex-in


tterwith

greatly

enhanced

output

power

(iii)Disp

lacementisn

otincreasedthus

notaggravatin

gfatig

ueprob

lem

(iv)E

asyto

implem

ent

(v)C

ut-in

windspeedisun

desir

ably

increased


Table4Con

tinued

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

per

volume(mWcm3)

Advantagesdisa

dvantagesa

ndother

inform

ation

Zhao

etal[3358]

Piezoelectric

Square

35

mdash114

50

Bluff

body

2times2times

10cm3


006

cm3

00274

(i)Em

ployed

synchron

ousc

harge

extractio

n(SCE

)elim

inates

the

requ

iremento

fimpedancem

atchingand

ensuresthe

flexibilityof

adjusting

the

harvesterfor

practic

alapplications

(ii)S

aving75

ofpiezoelectric

materials

bytheS

CEcomparedto

thes

tand

ard

circuit

(iii)Ac

hievingsm

allertransverse

displacementand

alleviatingfatig

ueprob

lem

with

SCE

Zhao

etal[5960]

Piezoelectric

Square

30

mdash325

70

Bluff

body

2times2times

10cm3


006

cm3

00782

(i)Synchron

ized

switching

harvestin

gon

indu

ctor

(SSH

I)enhances

output

powe

rcomparedto

stand

ardcircuit

(ii)S

SHIsho

wsm

ores

ignificantb

enefits

inweak-coup

lingsyste

msyetloses

benefitsinstr

ong-coup

lingcond

ition

s(iii)Ac

hieving143

power

increase

at7m

s

Bibo

etal[61]

Piezoelectric

Square

asymp22

mdash0348lowast1

45

Bluff

body

508times508times

1016

cm3


003

cm3

00013

(i)Con

currentfl

owandbase

excitatio

nsenhances

energy

harvestin

g(ii)B

asee

xcitatio

nim

proves

electrical

output

inresonancer

egion

(iii)Electricalou

tput

drop

sifb

ase

excitatio

nfre

quency

isclo

seto

buto

utsid

eof

resonancer

egion

Ewerea

ndWang

[62]

Piezoelectric

Square

2mdash

138

Bluff

body

5times5times

10cm3


004

cm3

bumpsto

pgapsiz

e05c

mcon

tactarea127

times4c

m2location

13cm

alon

gcantilever

00512

(i)Incorporatingan

impactbu

mpsto

psuccessfu

llyrelievesthe

fatig

ueprob

lem

(ii)A

chieving

substantial70

redu

ctionin

displacementamplitu

dewith

only20

voltage

redu

ction

lowast1Ca

lculated

by(59V)210

0kΩfro


Table1

andFigure12of

ther

eference


Table5Summaryof

vario

usflu

ttere

nergyharvesterd

evices

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Bryant

and

Garcia[

63]

Bryant

and

Garcia[

26]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoilprofi

leNAC

A0012

186

mdash22

79

Airfoilsemicho

rd297

cmspan136cm

Ca


00381cm3

717times10minus3

(i)Semiempiric

almod

elof

then

onlin

ear


aerodynamicsyste


ctric

alandmechanical

respon

se

(ii)S

uccessfully

predictsthefl

utterb

ound

arywith

oneo

fthe

realpartso

fthe

firsttwoeigenvalues

turningpo

sitivea

ndthetwoim

aginaryparts

coalescing

(iii)Wideo

peratio

nalw

indspeedrang

e(iv

)Sub

criticalH

opfb

ifurcation

alarge

initial

distu

rbance

isfund

amentalfor

syste

msta

rtup

Bryant

etal[64

]Piezoelectric

Mod

alconvergence

flutte

rFlatplate

Stiff

hoststr

ucture

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

Stiff

host

structure

(i)Com

paredto

astiff

hoststr

ucturea

compliant

hoststr

ucture

redu

cesthe

cut-inwindspeed

cut-infre

quency

andoscillatio

nfre

quency

(ii)Th

epeakpo

wer

isshifted

towardthelow

erwindspeeds

with

thec

ompliant

hoststr

ucture

173

2943

26200

Com

pliant

hoststr

ucture

Com

pliant

hoststr

ucture

152

2935

25163

Bryant

etal[65]

Piezoelectric

Mod

alconvergence

flutte

rFlatplate

173

2943

26

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

200

(i)Con

firmsthe

feasibilityof

usingam

bientfl

owenergy

harvestin

gto

power

aerodynamiccontrol

surfa

ces

Erturk

etal[66

]Piezoelectric

Mod

alconvergence

flutte

rAirfoil

930

mdash107

930

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

227times10minus3

(i)Eff

ecto


plingon

flutte

renergy

harvestin

gisanalyzed

(ii)F

ound

thattheo

ptim

alload

gave

the

maxim

umflu

tterspeed

duetothea

ssociated

maxim

umshun

tdam

ping

effectd

uringpo

wer

extractio

n

Sousae

tal[67]

Piezoelectric

Mod

alconvergence

flutte

rAirfoil

Linear

confi

guratio

n

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

Linear

confi

guratio

n255times10minus3

(i)Th

efreep

layno

nlinearityredu

cesthe

cut-in


utpu

tpow

er

(ii)Th

eoreticallydeterm

iningthattheh

ardening

stiffn

essb

rings

ther

espo

nsea

mplitu

deto


theo

peratio

nal

windspeedrang

e

121

mdash12

121

With

freep

layno

nlinearity

With

freep

lay

nonlinearity

100

mdash27

100

573times10minus3

Bibo

andDaqaq

[68]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoil

profi

leNAC

A0012

23

mdash0138lowast1

3(W

ithbase

acceleratio

n015ms2)

Airfoilsemicho

rd42c

mspan52c

m

Cantilevermdash

838times10minus4

(i)Con

currentfl

owandbase

excitatio

nsenhances

power

generatio

nperfo

rmance

(ii)C

oncurrentexcitatio

nsincreaseso

utpu

tpo

wer

by25tim

esbelowthefl

utterspeedand

over

3tim

esabovethe

flutte

rspeed

(iii)Ab

ovethe

flutte

rspeedrequirin

gcareful

adjustm

entb

ecause

power

issensitive

tobase

acceleratio

nfre

quency

Kwon

[69]

Piezoelectric

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

40

15

Flatplatetip60times

30c

m2


002

cm3

256

(i)SimpleT

-shape

structureeasyto

fabricate

(ii)N

orotatin

gcompo

nents

(iii)Wideo

peratio

nalw

indspeedrang

e


Table5Con

tinued

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Park

etal[70]

Electro

magnetic

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

118

Flatplatetip30times

20c

m2


001016c

m3

582


nsetof

theh

arveste

rrequ

iresthe

load


flutte

ron

setresistance

Lietal[71]

Piezoelectric

cross-flo

wflu

tter

mdash4

mdash0615

8adhereddo

uble-la

yer

stalk72times16times

004

1cm3

130

(i)Cr

oss-flo

wconfi

guratio

ngeneratedon

eorder

ofmagnitude

morep

ower

than

thep

arallel

confi

guratio

n(ii)H

avinghigh

power

density

perw

eightand

per

volume

(iii)Be

ingrobu

stsim

pleandminiature

sized

(iv)B

eing

easy

toblendin

urbanandnatural

environm

entsdu

etoits

ldquoleafrdquoa

ppearance

Deivasig

amaniet

al[72]

Piezoelectric

cross-flo

wflu

tter

Triang

lemdash

mdash00883

8

Isoscelestria

ngletip

8c

min

base8

cmin

height035

mm

inthickn

ess

Stalk72times16times

00205

cm3

00651


lkconfi

guratio

nis

superio

rtotheh

orizon

talstalkwith

fivetim

esmoreo

utpu

tpow

er

Hum

ding

erElectro

magnetic

cross-flo

wflu

tter

mdashmdash

mdashasymp9lowast2

10lowast3

Mem

brane12times07c

m2

Casin

g13times3times25c

m3

0923

(i)Successfu

llypo

wersw

irelesssensor

nodes

(ii)B

eing

compactandrobu

st(iii)Lo


peratio

nal

windspeedrang

e

Hob

ecketal[73]

Piezoelectric

Dual

cantilever

flutte

rmdash

asymp3

mdash0796

asymp13

Twoidentic


00254

cm3

0422

(i)Ve

rywideo

peratio

nalw

indspeedrang

ewith

efficientp

ower

generatio

n(ii)G

eneratingas

ignificantamou

ntof

power

from

3msto

15mswhengapissm

all

lowast1Ca

lculated

by18mwgtimes(015

ms298ms2)2

from


thea

utho

rsof

ther

eference


mthefi

gure

inthed


elt(http

wwwhu

mdingerwindcompdfm

icroBe

lt_briefp

df)


Table6Summaryof

vario

uswakeg

alloping

energy

harvesterd

evices

Author

Transductio

nPrism

shape

Cut-in

wind

speed

(ms)

Cut-o

utwind

speed

(ms)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Jung

andLee

[27]

Electro

magnetic

Circular

cylin

der

asymp12

mdash3704

45

Twoidentic

alcylin

ders5

cmin

dia

85cm

inleng

th

Spacingdistance

5times119863=25

cm

0111

(i)Determiningthep

roper

dista

nceb

etweenthep

arallel

cylin

dersforw

akeg

alloping

energy

harvestin

gas

4-5tim

esthec

ylinderd

iameterthatis

119871119863

=4sim

5(ii)H

ighou

tput

power

(iii)Wideo

peratio

nalw

ind

speedrange

(iv)D

evicev

olum

eistoo

big

Abdelkefi

etal[74]

Piezoelectric

Windw

ard

circular

cylin

der

Leew

ard

square

cylin

der

04

mdash004sim005

305

Circular

cylin

der

125c

min

dia

2715

cmin

leng

th

Square

cylin

der

128times12

8times

2667c

m3

Spacingdistance

24cm

Piezoelectric

two

identic


18times00305

cm3

572times10minus4

(i)Po

wer

from

agalloping

square

cylin

derw

asgreatly

enhanced

bywakee

ffectso

fanup

stream

circular

cylin

der

(ii)O

peratio

nalw

indspeed

rangew

aswidened

bywake

gallo

ping

(iii)Diameter

oftheu

pstre

amcylin

dera

ndthes

pacing

distance

betweentwocylin

dersrequ

irecarefuladjustm

ent


Table7Summaryof

vario

usTIVenergy

harvesterd

evices

Author

Transductio

nCu

t-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Akaydin

etal

[47]

Piezoelectric

asymp5lowast1


11

Bluff

body

3cm

india

12m

inleng

th

Cantilever3times16

times002

cm3

Distance

from

the

wall4c

m

648times10minus8

(i)Perfo

rmance

ofharvesterin

turbulentb

ound

arylayer

depend

sonthed

istance

from

the

walldo

minanto

scillation

frequ

ency

was

close

totheb

eam

resonancefrequ

ency

Hob

eckand

Inman

[28]

Piezoelectric

9sim10lowast2

mdash40

115

Bluff

body

445times

445times1092c

m3

Four

identic

alcantileversin

anarray1016

0mmtimes

2540m

mtimes

1016

0120583m

steel

substratea

ttached

with

4597m

mtimes

2057m

mtimes

15240120583m

PZT

00184

(i)Th

efirstT

IVenergy

harvestin

gmod

elwith

experim

entalvalidation

(ii)B

eing

robu

standsurvivable

duetoits

inherent

redu

ndancy

with

minor

redu

ctionin

total

power

caused

byon

edam

aged

elem

ent

(iii)Suitablefor

high

lyturbulent

fluid

flowenvironm

entslik

estr

eamso

rventilationsyste

ms

lowast1Obtainedfro

mtheinformationof

Figure11of

ther

eference

lowast2Obtainedfro

mtheinformationof

Figure7(b)o

fthe

reference



Author Transduction

Cut-inwindspeed(ms)


Maximumpower(mW)

Windspeed at

max power(ms)

Dimensions


(mWcm3)










40120583m

125 times 10minus5



Z

h

dX

(a)

Lp

L tip

Lb

tp tbBp Bb

(b)










Wind

Bluff body

Inner beam

Outer beam

Magnets


Fixed end







h

U

kh

휃

k휃


























































Wind flows

Substrate

Gallopingenergy

y

L1 L2 L3

x1

x2

x3

harvester

(a)

VIVenergy harvester



(b)


NACA 0012 airfoil


Revolute joint

(c)






ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL


OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n


Vc1











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation









































Section shape







Table4Summaryof

vario

usgallo

ping

energy

harvesterd

evices

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

per

volume(mWcm3)

Advantagesdisa

dvantagesa

ndother

inform

ation

Sirohi

and

Mahadik[54]

Piezoelectric

Triang

le36

61

5052

Bluff

body

4c

min

side251cm

inleng

th


00635

cm3

0281

(i)Highpeak

power

isachievedw

ithhigh


pling

(ii)V

alidates

thefeasib

ilityof

predictin

ggallo

ping

energy

harvesterrsquos

respon

sewith

quasi-steadyhypo

thesis

(iii)Ab

rupt

decrease

inou

tput

power

at61m

sisun

desired

Sirohi

and

Mahadik[55]

Piezoelectric

D-shape

25

mdash114

47

Bluff

body

3cm

india

235cm

inleng

th

cantilever

9times38times00635

cm3

00134

(i)Outpu

tpow

ercontinuo

uslyincreases

with

windspeedwith

nocut-o

utwind

speed

(ii)W

ideo

peratio

nalw

indspeedrang

e(iii)Re

quiring

turbulentfl

owto

functio

nwellfore

xampleflo

wfro

mar

otatingfan

becauseD

-shape

cann

otself-oscillatein

laminar

flow

(iv)C

antilever

andbluff

body

prism

arein

parallel

Zhao

etal[56]

Yang

etal[32]

Piezoelectric

Square

25

mdash84

80

Bluff

body

4times4times

15cm3

cantilever

15times3times006

cm3

00346

(i)Ex

perim

entally

determ

iningforthe

first

timethatthe

square

sectionisop

timalfor

gallo

ping

energy

harvestin

gcomparedto

othershapesgiving

thelargestpo

wer

and

thelow

estcut-in

windspeed

(ii)H

ighpeak

power

isachievedw

ithhigh


pling

(iii)Wideo

peratio

nalw

indspeedrang

e

Zhao

etal[57]

Piezoelectric

Square

10mdash

450

Bluff

body

4times4times

15cm3

cut-o

utcantileverinner

beam

57times3times

003

cm3

outerb

eam172times66times

006

cm3with

cuto

utat

theinn

erbeam

locatio

n

00162

(i)2D

OFcut-o

utstr

ucture

with

magnetic

interaction

(ii)R

educingthec

ut-in

speed

(iii)En

hancingou

tput

power

inthelow

windspeedrang

e(iv

)Havingstiffn

essn

onlin

earityindu

ced

bymagnetic

interaction

(v)O

utpu

tpow

erislim

itedin

high

wind

speeds

Zhao

andYang

[24]

Piezoelectric

Square

20

mdash12

80

Bluff

body

4times4times

15cm3


006

cm3

beam


05c

m3

00455

(i)Em

ployed

beam

stiffenera

sele

ctromechanicalcou

plingmagnifier

(ii)E

ffectivefor

allthree

typeso

fharvestersbasedon

gallo

ping

vortex-in


tterwith

greatly

enhanced

output

power

(iii)Disp

lacementisn

otincreasedthus

notaggravatin

gfatig

ueprob

lem

(iv)E

asyto

implem

ent

(v)C

ut-in

windspeedisun

desir

ably

increased


Table4Con

tinued

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

per

volume(mWcm3)

Advantagesdisa

dvantagesa

ndother

inform

ation

Zhao

etal[3358]

Piezoelectric

Square

35

mdash114

50

Bluff

body

2times2times

10cm3


006

cm3

00274

(i)Em

ployed

synchron

ousc

harge

extractio

n(SCE

)elim

inates

the

requ

iremento

fimpedancem

atchingand

ensuresthe

flexibilityof

adjusting

the

harvesterfor

practic

alapplications

(ii)S

aving75

ofpiezoelectric

materials

bytheS

CEcomparedto

thes

tand

ard

circuit

(iii)Ac

hievingsm

allertransverse

displacementand

alleviatingfatig

ueprob

lem

with

SCE

Zhao

etal[5960]

Piezoelectric

Square

30

mdash325

70

Bluff

body

2times2times

10cm3


006

cm3

00782

(i)Synchron

ized

switching

harvestin

gon

indu

ctor

(SSH

I)enhances

output

powe

rcomparedto

stand

ardcircuit

(ii)S

SHIsho

wsm

ores

ignificantb

enefits

inweak-coup

lingsyste

msyetloses

benefitsinstr

ong-coup

lingcond

ition

s(iii)Ac

hieving143

power

increase

at7m

s

Bibo

etal[61]

Piezoelectric

Square

asymp22

mdash0348lowast1

45

Bluff

body

508times508times

1016

cm3


003

cm3

00013

(i)Con

currentfl

owandbase

excitatio

nsenhances

energy

harvestin

g(ii)B

asee

xcitatio

nim

proves

electrical

output

inresonancer

egion

(iii)Electricalou

tput

drop

sifb

ase

excitatio

nfre

quency

isclo

seto

buto

utsid

eof

resonancer

egion

Ewerea

ndWang

[62]

Piezoelectric

Square

2mdash

138

Bluff

body

5times5times

10cm3


004

cm3

bumpsto

pgapsiz

e05c

mcon

tactarea127

times4c

m2location

13cm

alon

gcantilever

00512

(i)Incorporatingan

impactbu

mpsto

psuccessfu

llyrelievesthe

fatig

ueprob

lem

(ii)A

chieving

substantial70

redu

ctionin

displacementamplitu

dewith

only20

voltage

redu

ction

lowast1Ca

lculated

by(59V)210

0kΩfro


Table1

andFigure12of

ther

eference


Table5Summaryof

vario

usflu

ttere

nergyharvesterd

evices

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Bryant

and

Garcia[

63]

Bryant

and

Garcia[

26]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoilprofi

leNAC

A0012

186

mdash22

79

Airfoilsemicho

rd297

cmspan136cm

Ca


00381cm3

717times10minus3

(i)Semiempiric

almod

elof

then

onlin

ear


aerodynamicsyste


ctric

alandmechanical

respon

se

(ii)S

uccessfully

predictsthefl

utterb

ound

arywith

oneo

fthe

realpartso

fthe

firsttwoeigenvalues

turningpo

sitivea

ndthetwoim

aginaryparts

coalescing

(iii)Wideo

peratio

nalw

indspeedrang

e(iv

)Sub

criticalH

opfb

ifurcation

alarge

initial

distu

rbance

isfund

amentalfor

syste

msta

rtup

Bryant

etal[64

]Piezoelectric

Mod

alconvergence

flutte

rFlatplate

Stiff

hoststr

ucture

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

Stiff

host

structure

(i)Com

paredto

astiff

hoststr

ucturea

compliant

hoststr

ucture

redu

cesthe

cut-inwindspeed

cut-infre

quency

andoscillatio

nfre

quency

(ii)Th

epeakpo

wer

isshifted

towardthelow

erwindspeeds

with

thec

ompliant

hoststr

ucture

173

2943

26200

Com

pliant

hoststr

ucture

Com

pliant

hoststr

ucture

152

2935

25163

Bryant

etal[65]

Piezoelectric

Mod

alconvergence

flutte

rFlatplate

173

2943

26

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

200

(i)Con

firmsthe

feasibilityof

usingam

bientfl

owenergy

harvestin

gto

power

aerodynamiccontrol

surfa

ces

Erturk

etal[66

]Piezoelectric

Mod

alconvergence

flutte

rAirfoil

930

mdash107

930

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

227times10minus3

(i)Eff

ecto


plingon

flutte

renergy

harvestin

gisanalyzed

(ii)F

ound

thattheo

ptim

alload

gave

the

maxim

umflu

tterspeed

duetothea

ssociated

maxim

umshun

tdam

ping

effectd

uringpo

wer

extractio

n

Sousae

tal[67]

Piezoelectric

Mod

alconvergence

flutte

rAirfoil

Linear

confi

guratio

n

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

Linear

confi

guratio

n255times10minus3

(i)Th

efreep

layno

nlinearityredu

cesthe

cut-in


utpu

tpow

er

(ii)Th

eoreticallydeterm

iningthattheh

ardening

stiffn

essb

rings

ther

espo

nsea

mplitu

deto


theo

peratio

nal

windspeedrang

e

121

mdash12

121

With

freep

layno

nlinearity

With

freep

lay

nonlinearity

100

mdash27

100

573times10minus3

Bibo

andDaqaq

[68]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoil

profi

leNAC

A0012

23

mdash0138lowast1

3(W

ithbase

acceleratio

n015ms2)

Airfoilsemicho

rd42c

mspan52c

m

Cantilevermdash

838times10minus4

(i)Con

currentfl

owandbase

excitatio

nsenhances

power

generatio

nperfo

rmance

(ii)C

oncurrentexcitatio

nsincreaseso

utpu

tpo

wer

by25tim

esbelowthefl

utterspeedand

over

3tim

esabovethe

flutte

rspeed

(iii)Ab

ovethe

flutte

rspeedrequirin

gcareful

adjustm

entb

ecause

power

issensitive

tobase

acceleratio

nfre

quency

Kwon

[69]

Piezoelectric

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

40

15

Flatplatetip60times

30c

m2


002

cm3

256

(i)SimpleT

-shape

structureeasyto

fabricate

(ii)N

orotatin

gcompo

nents

(iii)Wideo

peratio

nalw

indspeedrang

e


Table5Con

tinued

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Park

etal[70]

Electro

magnetic

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

118

Flatplatetip30times

20c

m2


001016c

m3

582


nsetof

theh

arveste

rrequ

iresthe

load


flutte

ron

setresistance

Lietal[71]

Piezoelectric

cross-flo

wflu

tter

mdash4

mdash0615

8adhereddo

uble-la

yer

stalk72times16times

004

1cm3

130

(i)Cr

oss-flo

wconfi

guratio

ngeneratedon

eorder

ofmagnitude

morep

ower

than

thep

arallel

confi

guratio

n(ii)H

avinghigh

power

density

perw

eightand

per

volume

(iii)Be

ingrobu

stsim

pleandminiature

sized

(iv)B

eing

easy

toblendin

urbanandnatural

environm

entsdu

etoits

ldquoleafrdquoa

ppearance

Deivasig

amaniet

al[72]

Piezoelectric

cross-flo

wflu

tter

Triang

lemdash

mdash00883

8

Isoscelestria

ngletip

8c

min

base8

cmin

height035

mm

inthickn

ess

Stalk72times16times

00205

cm3

00651


lkconfi

guratio

nis

superio

rtotheh

orizon

talstalkwith

fivetim

esmoreo

utpu

tpow

er

Hum

ding

erElectro

magnetic

cross-flo

wflu

tter

mdashmdash

mdashasymp9lowast2

10lowast3

Mem

brane12times07c

m2

Casin

g13times3times25c

m3

0923

(i)Successfu

llypo

wersw

irelesssensor

nodes

(ii)B

eing

compactandrobu

st(iii)Lo


peratio

nal

windspeedrang

e

Hob

ecketal[73]

Piezoelectric

Dual

cantilever

flutte

rmdash

asymp3

mdash0796

asymp13

Twoidentic


00254

cm3

0422

(i)Ve

rywideo

peratio

nalw

indspeedrang

ewith

efficientp

ower

generatio

n(ii)G

eneratingas

ignificantamou

ntof

power

from

3msto

15mswhengapissm

all

lowast1Ca

lculated

by18mwgtimes(015

ms298ms2)2

from


thea

utho

rsof

ther

eference


mthefi

gure

inthed


elt(http

wwwhu

mdingerwindcompdfm

icroBe

lt_briefp

df)


Table6Summaryof

vario

uswakeg

alloping

energy

harvesterd

evices

Author

Transductio

nPrism

shape

Cut-in

wind

speed

(ms)

Cut-o

utwind

speed

(ms)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Jung

andLee

[27]

Electro

magnetic

Circular

cylin

der

asymp12

mdash3704

45

Twoidentic

alcylin

ders5

cmin

dia

85cm

inleng

th

Spacingdistance

5times119863=25

cm

0111

(i)Determiningthep

roper

dista

nceb

etweenthep

arallel

cylin

dersforw

akeg

alloping

energy

harvestin

gas

4-5tim

esthec

ylinderd

iameterthatis

119871119863

=4sim

5(ii)H

ighou

tput

power

(iii)Wideo

peratio

nalw

ind

speedrange

(iv)D

evicev

olum

eistoo

big

Abdelkefi

etal[74]

Piezoelectric

Windw

ard

circular

cylin

der

Leew

ard

square

cylin

der

04

mdash004sim005

305

Circular

cylin

der

125c

min

dia

2715

cmin

leng

th

Square

cylin

der

128times12

8times

2667c

m3

Spacingdistance

24cm

Piezoelectric

two

identic


18times00305

cm3

572times10minus4

(i)Po

wer

from

agalloping

square

cylin

derw

asgreatly

enhanced

bywakee

ffectso

fanup

stream

circular

cylin

der

(ii)O

peratio

nalw

indspeed

rangew

aswidened

bywake

gallo

ping

(iii)Diameter

oftheu

pstre

amcylin

dera

ndthes

pacing

distance

betweentwocylin

dersrequ

irecarefuladjustm

ent


Table7Summaryof

vario

usTIVenergy

harvesterd

evices

Author

Transductio

nCu

t-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Akaydin

etal

[47]

Piezoelectric

asymp5lowast1


11

Bluff

body

3cm

india

12m

inleng

th

Cantilever3times16

times002

cm3

Distance

from

the

wall4c

m

648times10minus8

(i)Perfo

rmance

ofharvesterin

turbulentb

ound

arylayer

depend

sonthed

istance

from

the

walldo

minanto

scillation

frequ

ency

was

close

totheb

eam

resonancefrequ

ency

Hob

eckand

Inman

[28]

Piezoelectric

9sim10lowast2

mdash40

115

Bluff

body

445times

445times1092c

m3

Four

identic

alcantileversin

anarray1016

0mmtimes

2540m

mtimes

1016

0120583m

steel

substratea

ttached

with

4597m

mtimes

2057m

mtimes

15240120583m

PZT

00184

(i)Th

efirstT

IVenergy

harvestin

gmod

elwith

experim

entalvalidation

(ii)B

eing

robu

standsurvivable

duetoits

inherent

redu

ndancy

with

minor

redu

ctionin

total

power

caused

byon

edam

aged

elem

ent

(iii)Suitablefor

high

lyturbulent

fluid

flowenvironm

entslik

estr

eamso

rventilationsyste

ms

lowast1Obtainedfro

mtheinformationof

Figure11of

ther

eference

lowast2Obtainedfro

mtheinformationof

Figure7(b)o

fthe

reference



Author Transduction

Cut-inwindspeed(ms)


Maximumpower(mW)

Windspeed at

max power(ms)

Dimensions


(mWcm3)










40120583m

125 times 10minus5



Z

h

dX

(a)

Lp

L tip

Lb

tp tbBp Bb

(b)










Wind

Bluff body

Inner beam

Outer beam

Magnets


Fixed end







h

U

kh

휃

k휃


























































Wind flows

Substrate

Gallopingenergy

y

L1 L2 L3

x1

x2

x3

harvester

(a)

VIVenergy harvester



(b)


NACA 0012 airfoil


Revolute joint

(c)






ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL


OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n


Vc1











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Table4Summaryof

vario

usgallo

ping

energy

harvesterd

evices

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

per

volume(mWcm3)

Advantagesdisa

dvantagesa

ndother

inform

ation

Sirohi

and

Mahadik[54]

Piezoelectric

Triang

le36

61

5052

Bluff

body

4c

min

side251cm

inleng

th


00635

cm3

0281

(i)Highpeak

power

isachievedw

ithhigh


pling

(ii)V

alidates

thefeasib

ilityof

predictin

ggallo

ping

energy

harvesterrsquos

respon

sewith

quasi-steadyhypo

thesis

(iii)Ab

rupt

decrease

inou

tput

power

at61m

sisun

desired

Sirohi

and

Mahadik[55]

Piezoelectric

D-shape

25

mdash114

47

Bluff

body

3cm

india

235cm

inleng

th

cantilever

9times38times00635

cm3

00134

(i)Outpu

tpow

ercontinuo

uslyincreases

with

windspeedwith

nocut-o

utwind

speed

(ii)W

ideo

peratio

nalw

indspeedrang

e(iii)Re

quiring

turbulentfl

owto

functio

nwellfore

xampleflo

wfro

mar

otatingfan

becauseD

-shape

cann

otself-oscillatein

laminar

flow

(iv)C

antilever

andbluff

body

prism

arein

parallel

Zhao

etal[56]

Yang

etal[32]

Piezoelectric

Square

25

mdash84

80

Bluff

body

4times4times

15cm3

cantilever

15times3times006

cm3

00346

(i)Ex

perim

entally

determ

iningforthe

first

timethatthe

square

sectionisop

timalfor

gallo

ping

energy

harvestin

gcomparedto

othershapesgiving

thelargestpo

wer

and

thelow

estcut-in

windspeed

(ii)H

ighpeak

power

isachievedw

ithhigh


pling

(iii)Wideo

peratio

nalw

indspeedrang

e

Zhao

etal[57]

Piezoelectric

Square

10mdash

450

Bluff

body

4times4times

15cm3

cut-o

utcantileverinner

beam

57times3times

003

cm3

outerb

eam172times66times

006

cm3with

cuto

utat

theinn

erbeam

locatio

n

00162

(i)2D

OFcut-o

utstr

ucture

with

magnetic

interaction

(ii)R

educingthec

ut-in

speed

(iii)En

hancingou

tput

power

inthelow

windspeedrang

e(iv

)Havingstiffn

essn

onlin

earityindu

ced

bymagnetic

interaction

(v)O

utpu

tpow

erislim

itedin

high

wind

speeds

Zhao

andYang

[24]

Piezoelectric

Square

20

mdash12

80

Bluff

body

4times4times

15cm3


006

cm3

beam


05c

m3

00455

(i)Em

ployed

beam

stiffenera

sele

ctromechanicalcou

plingmagnifier

(ii)E

ffectivefor

allthree

typeso

fharvestersbasedon

gallo

ping

vortex-in


tterwith

greatly

enhanced

output

power

(iii)Disp

lacementisn

otincreasedthus

notaggravatin

gfatig

ueprob

lem

(iv)E

asyto

implem

ent

(v)C

ut-in

windspeedisun

desir

ably

increased


Table4Con

tinued

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

per

volume(mWcm3)

Advantagesdisa

dvantagesa

ndother

inform

ation

Zhao

etal[3358]

Piezoelectric

Square

35

mdash114

50

Bluff

body

2times2times

10cm3


006

cm3

00274

(i)Em

ployed

synchron

ousc

harge

extractio

n(SCE

)elim

inates

the

requ

iremento

fimpedancem

atchingand

ensuresthe

flexibilityof

adjusting

the

harvesterfor

practic

alapplications

(ii)S

aving75

ofpiezoelectric

materials

bytheS

CEcomparedto

thes

tand

ard

circuit

(iii)Ac

hievingsm

allertransverse

displacementand

alleviatingfatig

ueprob

lem

with

SCE

Zhao

etal[5960]

Piezoelectric

Square

30

mdash325

70

Bluff

body

2times2times

10cm3


006

cm3

00782

(i)Synchron

ized

switching

harvestin

gon

indu

ctor

(SSH

I)enhances

output

powe

rcomparedto

stand

ardcircuit

(ii)S

SHIsho

wsm

ores

ignificantb

enefits

inweak-coup

lingsyste

msyetloses

benefitsinstr

ong-coup

lingcond

ition

s(iii)Ac

hieving143

power

increase

at7m

s

Bibo

etal[61]

Piezoelectric

Square

asymp22

mdash0348lowast1

45

Bluff

body

508times508times

1016

cm3


003

cm3

00013

(i)Con

currentfl

owandbase

excitatio

nsenhances

energy

harvestin

g(ii)B

asee

xcitatio

nim

proves

electrical

output

inresonancer

egion

(iii)Electricalou

tput

drop

sifb

ase

excitatio

nfre

quency

isclo

seto

buto

utsid

eof

resonancer

egion

Ewerea

ndWang

[62]

Piezoelectric

Square

2mdash

138

Bluff

body

5times5times

10cm3


004

cm3

bumpsto

pgapsiz

e05c

mcon

tactarea127

times4c

m2location

13cm

alon

gcantilever

00512

(i)Incorporatingan

impactbu

mpsto

psuccessfu

llyrelievesthe

fatig

ueprob

lem

(ii)A

chieving

substantial70

redu

ctionin

displacementamplitu

dewith

only20

voltage

redu

ction

lowast1Ca

lculated

by(59V)210

0kΩfro


Table1

andFigure12of

ther

eference


Table5Summaryof

vario

usflu

ttere

nergyharvesterd

evices

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Bryant

and

Garcia[

63]

Bryant

and

Garcia[

26]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoilprofi

leNAC

A0012

186

mdash22

79

Airfoilsemicho

rd297

cmspan136cm

Ca


00381cm3

717times10minus3

(i)Semiempiric

almod

elof

then

onlin

ear


aerodynamicsyste


ctric

alandmechanical

respon

se

(ii)S

uccessfully

predictsthefl

utterb

ound

arywith

oneo

fthe

realpartso

fthe

firsttwoeigenvalues

turningpo

sitivea

ndthetwoim

aginaryparts

coalescing

(iii)Wideo

peratio

nalw

indspeedrang

e(iv

)Sub

criticalH

opfb

ifurcation

alarge

initial

distu

rbance

isfund

amentalfor

syste

msta

rtup

Bryant

etal[64

]Piezoelectric

Mod

alconvergence

flutte

rFlatplate

Stiff

hoststr

ucture

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

Stiff

host

structure

(i)Com

paredto

astiff

hoststr

ucturea

compliant

hoststr

ucture

redu

cesthe

cut-inwindspeed

cut-infre

quency

andoscillatio

nfre

quency

(ii)Th

epeakpo

wer

isshifted

towardthelow

erwindspeeds

with

thec

ompliant

hoststr

ucture

173

2943

26200

Com

pliant

hoststr

ucture

Com

pliant

hoststr

ucture

152

2935

25163

Bryant

etal[65]

Piezoelectric

Mod

alconvergence

flutte

rFlatplate

173

2943

26

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

200

(i)Con

firmsthe

feasibilityof

usingam

bientfl

owenergy

harvestin

gto

power

aerodynamiccontrol

surfa

ces

Erturk

etal[66

]Piezoelectric

Mod

alconvergence

flutte

rAirfoil

930

mdash107

930

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

227times10minus3

(i)Eff

ecto


plingon

flutte

renergy

harvestin

gisanalyzed

(ii)F

ound

thattheo

ptim

alload

gave

the

maxim

umflu

tterspeed

duetothea

ssociated

maxim

umshun

tdam

ping

effectd

uringpo

wer

extractio

n

Sousae

tal[67]

Piezoelectric

Mod

alconvergence

flutte

rAirfoil

Linear

confi

guratio

n

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

Linear

confi

guratio

n255times10minus3

(i)Th

efreep

layno

nlinearityredu

cesthe

cut-in


utpu

tpow

er

(ii)Th

eoreticallydeterm

iningthattheh

ardening

stiffn

essb

rings

ther

espo

nsea

mplitu

deto


theo

peratio

nal

windspeedrang

e

121

mdash12

121

With

freep

layno

nlinearity

With

freep

lay

nonlinearity

100

mdash27

100

573times10minus3

Bibo

andDaqaq

[68]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoil

profi

leNAC

A0012

23

mdash0138lowast1

3(W

ithbase

acceleratio

n015ms2)

Airfoilsemicho

rd42c

mspan52c

m

Cantilevermdash

838times10minus4

(i)Con

currentfl

owandbase

excitatio

nsenhances

power

generatio

nperfo

rmance

(ii)C

oncurrentexcitatio

nsincreaseso

utpu

tpo

wer

by25tim

esbelowthefl

utterspeedand

over

3tim

esabovethe

flutte

rspeed

(iii)Ab

ovethe

flutte

rspeedrequirin

gcareful

adjustm

entb

ecause

power

issensitive

tobase

acceleratio

nfre

quency

Kwon

[69]

Piezoelectric

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

40

15

Flatplatetip60times

30c

m2


002

cm3

256

(i)SimpleT

-shape

structureeasyto

fabricate

(ii)N

orotatin

gcompo

nents

(iii)Wideo

peratio

nalw

indspeedrang

e


Table5Con

tinued

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Park

etal[70]

Electro

magnetic

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

118

Flatplatetip30times

20c

m2


001016c

m3

582


nsetof

theh

arveste

rrequ

iresthe

load


flutte

ron

setresistance

Lietal[71]

Piezoelectric

cross-flo

wflu

tter

mdash4

mdash0615

8adhereddo

uble-la

yer

stalk72times16times

004

1cm3

130

(i)Cr

oss-flo

wconfi

guratio

ngeneratedon

eorder

ofmagnitude

morep

ower

than

thep

arallel

confi

guratio

n(ii)H

avinghigh

power

density

perw

eightand

per

volume

(iii)Be

ingrobu

stsim

pleandminiature

sized

(iv)B

eing

easy

toblendin

urbanandnatural

environm

entsdu

etoits

ldquoleafrdquoa

ppearance

Deivasig

amaniet

al[72]

Piezoelectric

cross-flo

wflu

tter

Triang

lemdash

mdash00883

8

Isoscelestria

ngletip

8c

min

base8

cmin

height035

mm

inthickn

ess

Stalk72times16times

00205

cm3

00651


lkconfi

guratio

nis

superio

rtotheh

orizon

talstalkwith

fivetim

esmoreo

utpu

tpow

er

Hum

ding

erElectro

magnetic

cross-flo

wflu

tter

mdashmdash

mdashasymp9lowast2

10lowast3

Mem

brane12times07c

m2

Casin

g13times3times25c

m3

0923

(i)Successfu

llypo

wersw

irelesssensor

nodes

(ii)B

eing

compactandrobu

st(iii)Lo


peratio

nal

windspeedrang

e

Hob

ecketal[73]

Piezoelectric

Dual

cantilever

flutte

rmdash

asymp3

mdash0796

asymp13

Twoidentic


00254

cm3

0422

(i)Ve

rywideo

peratio

nalw

indspeedrang

ewith

efficientp

ower

generatio

n(ii)G

eneratingas

ignificantamou

ntof

power

from

3msto

15mswhengapissm

all

lowast1Ca

lculated

by18mwgtimes(015

ms298ms2)2

from


thea

utho

rsof

ther

eference


mthefi

gure

inthed


elt(http

wwwhu

mdingerwindcompdfm

icroBe

lt_briefp

df)


Table6Summaryof

vario

uswakeg

alloping

energy

harvesterd

evices

Author

Transductio

nPrism

shape

Cut-in

wind

speed

(ms)

Cut-o

utwind

speed

(ms)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Jung

andLee

[27]

Electro

magnetic

Circular

cylin

der

asymp12

mdash3704

45

Twoidentic

alcylin

ders5

cmin

dia

85cm

inleng

th

Spacingdistance

5times119863=25

cm

0111

(i)Determiningthep

roper

dista

nceb

etweenthep

arallel

cylin

dersforw

akeg

alloping

energy

harvestin

gas

4-5tim

esthec

ylinderd

iameterthatis

119871119863

=4sim

5(ii)H

ighou

tput

power

(iii)Wideo

peratio

nalw

ind

speedrange

(iv)D

evicev

olum

eistoo

big

Abdelkefi

etal[74]

Piezoelectric

Windw

ard

circular

cylin

der

Leew

ard

square

cylin

der

04

mdash004sim005

305

Circular

cylin

der

125c

min

dia

2715

cmin

leng

th

Square

cylin

der

128times12

8times

2667c

m3

Spacingdistance

24cm

Piezoelectric

two

identic


18times00305

cm3

572times10minus4

(i)Po

wer

from

agalloping

square

cylin

derw

asgreatly

enhanced

bywakee

ffectso

fanup

stream

circular

cylin

der

(ii)O

peratio

nalw

indspeed

rangew

aswidened

bywake

gallo

ping

(iii)Diameter

oftheu

pstre

amcylin

dera

ndthes

pacing

distance

betweentwocylin

dersrequ

irecarefuladjustm

ent


Table7Summaryof

vario

usTIVenergy

harvesterd

evices

Author

Transductio

nCu

t-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Akaydin

etal

[47]

Piezoelectric

asymp5lowast1


11

Bluff

body

3cm

india

12m

inleng

th

Cantilever3times16

times002

cm3

Distance

from

the

wall4c

m

648times10minus8

(i)Perfo

rmance

ofharvesterin

turbulentb

ound

arylayer

depend

sonthed

istance

from

the

walldo

minanto

scillation

frequ

ency

was

close

totheb

eam

resonancefrequ

ency

Hob

eckand

Inman

[28]

Piezoelectric

9sim10lowast2

mdash40

115

Bluff

body

445times

445times1092c

m3

Four

identic

alcantileversin

anarray1016

0mmtimes

2540m

mtimes

1016

0120583m

steel

substratea

ttached

with

4597m

mtimes

2057m

mtimes

15240120583m

PZT

00184

(i)Th

efirstT

IVenergy

harvestin

gmod

elwith

experim

entalvalidation

(ii)B

eing

robu

standsurvivable

duetoits

inherent

redu

ndancy

with

minor

redu

ctionin

total

power

caused

byon

edam

aged

elem

ent

(iii)Suitablefor

high

lyturbulent

fluid

flowenvironm

entslik

estr

eamso

rventilationsyste

ms

lowast1Obtainedfro

mtheinformationof

Figure11of

ther

eference

lowast2Obtainedfro

mtheinformationof

Figure7(b)o

fthe

reference



Author Transduction

Cut-inwindspeed(ms)


Maximumpower(mW)

Windspeed at

max power(ms)

Dimensions


(mWcm3)










40120583m

125 times 10minus5



Z

h

dX

(a)

Lp

L tip

Lb

tp tbBp Bb

(b)










Wind

Bluff body

Inner beam

Outer beam

Magnets


Fixed end







h

U

kh

휃

k휃


























































Wind flows

Substrate

Gallopingenergy

y

L1 L2 L3

x1

x2

x3

harvester

(a)

VIVenergy harvester



(b)


NACA 0012 airfoil


Revolute joint

(c)






ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL


OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n


Vc1











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Table4Con

tinued

Author

Transductio

nBluff

body

shape

Cut-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

per

volume(mWcm3)

Advantagesdisa

dvantagesa

ndother

inform

ation

Zhao

etal[3358]

Piezoelectric

Square

35

mdash114

50

Bluff

body

2times2times

10cm3


006

cm3

00274

(i)Em

ployed

synchron

ousc

harge

extractio

n(SCE

)elim

inates

the

requ

iremento

fimpedancem

atchingand

ensuresthe

flexibilityof

adjusting

the

harvesterfor

practic

alapplications

(ii)S

aving75

ofpiezoelectric

materials

bytheS

CEcomparedto

thes

tand

ard

circuit

(iii)Ac

hievingsm

allertransverse

displacementand

alleviatingfatig

ueprob

lem

with

SCE

Zhao

etal[5960]

Piezoelectric

Square

30

mdash325

70

Bluff

body

2times2times

10cm3


006

cm3

00782

(i)Synchron

ized

switching

harvestin

gon

indu

ctor

(SSH

I)enhances

output

powe

rcomparedto

stand

ardcircuit

(ii)S

SHIsho

wsm

ores

ignificantb

enefits

inweak-coup

lingsyste

msyetloses

benefitsinstr

ong-coup

lingcond

ition

s(iii)Ac

hieving143

power

increase

at7m

s

Bibo

etal[61]

Piezoelectric

Square

asymp22

mdash0348lowast1

45

Bluff

body

508times508times

1016

cm3


003

cm3

00013

(i)Con

currentfl

owandbase

excitatio

nsenhances

energy

harvestin

g(ii)B

asee

xcitatio

nim

proves

electrical

output

inresonancer

egion

(iii)Electricalou

tput

drop

sifb

ase

excitatio

nfre

quency

isclo

seto

buto

utsid

eof

resonancer

egion

Ewerea

ndWang

[62]

Piezoelectric

Square

2mdash

138

Bluff

body

5times5times

10cm3


004

cm3

bumpsto

pgapsiz

e05c

mcon

tactarea127

times4c

m2location

13cm

alon

gcantilever

00512

(i)Incorporatingan

impactbu

mpsto

psuccessfu

llyrelievesthe

fatig

ueprob

lem

(ii)A

chieving

substantial70

redu

ctionin

displacementamplitu

dewith

only20

voltage

redu

ction

lowast1Ca

lculated

by(59V)210

0kΩfro


Table1

andFigure12of

ther

eference


Table5Summaryof

vario

usflu

ttere

nergyharvesterd

evices

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Bryant

and

Garcia[

63]

Bryant

and

Garcia[

26]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoilprofi

leNAC

A0012

186

mdash22

79

Airfoilsemicho

rd297

cmspan136cm

Ca


00381cm3

717times10minus3

(i)Semiempiric

almod

elof

then

onlin

ear


aerodynamicsyste


ctric

alandmechanical

respon

se

(ii)S

uccessfully

predictsthefl

utterb

ound

arywith

oneo

fthe

realpartso

fthe

firsttwoeigenvalues

turningpo

sitivea

ndthetwoim

aginaryparts

coalescing

(iii)Wideo

peratio

nalw

indspeedrang

e(iv

)Sub

criticalH

opfb

ifurcation

alarge

initial

distu

rbance

isfund

amentalfor

syste

msta

rtup

Bryant

etal[64

]Piezoelectric

Mod

alconvergence

flutte

rFlatplate

Stiff

hoststr

ucture

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

Stiff

host

structure

(i)Com

paredto

astiff

hoststr

ucturea

compliant

hoststr

ucture

redu

cesthe

cut-inwindspeed

cut-infre

quency

andoscillatio

nfre

quency

(ii)Th

epeakpo

wer

isshifted

towardthelow

erwindspeeds

with

thec

ompliant

hoststr

ucture

173

2943

26200

Com

pliant

hoststr

ucture

Com

pliant

hoststr

ucture

152

2935

25163

Bryant

etal[65]

Piezoelectric

Mod

alconvergence

flutte

rFlatplate

173

2943

26

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

200

(i)Con

firmsthe

feasibilityof

usingam

bientfl

owenergy

harvestin

gto

power

aerodynamiccontrol

surfa

ces

Erturk

etal[66

]Piezoelectric

Mod

alconvergence

flutte

rAirfoil

930

mdash107

930

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

227times10minus3

(i)Eff

ecto


plingon

flutte

renergy

harvestin

gisanalyzed

(ii)F

ound

thattheo

ptim

alload

gave

the

maxim

umflu

tterspeed

duetothea

ssociated

maxim

umshun

tdam

ping

effectd

uringpo

wer

extractio

n

Sousae

tal[67]

Piezoelectric

Mod

alconvergence

flutte

rAirfoil

Linear

confi

guratio

n

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

Linear

confi

guratio

n255times10minus3

(i)Th

efreep

layno

nlinearityredu

cesthe

cut-in


utpu

tpow

er

(ii)Th

eoreticallydeterm

iningthattheh

ardening

stiffn

essb

rings

ther

espo

nsea

mplitu

deto


theo

peratio

nal

windspeedrang

e

121

mdash12

121

With

freep

layno

nlinearity

With

freep

lay

nonlinearity

100

mdash27

100

573times10minus3

Bibo

andDaqaq

[68]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoil

profi

leNAC

A0012

23

mdash0138lowast1

3(W

ithbase

acceleratio

n015ms2)

Airfoilsemicho

rd42c

mspan52c

m

Cantilevermdash

838times10minus4

(i)Con

currentfl

owandbase

excitatio

nsenhances

power

generatio

nperfo

rmance

(ii)C

oncurrentexcitatio

nsincreaseso

utpu

tpo

wer

by25tim

esbelowthefl

utterspeedand

over

3tim

esabovethe

flutte

rspeed

(iii)Ab

ovethe

flutte

rspeedrequirin

gcareful

adjustm

entb

ecause

power

issensitive

tobase

acceleratio

nfre

quency

Kwon

[69]

Piezoelectric

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

40

15

Flatplatetip60times

30c

m2


002

cm3

256

(i)SimpleT

-shape

structureeasyto

fabricate

(ii)N

orotatin

gcompo

nents

(iii)Wideo

peratio

nalw

indspeedrang

e


Table5Con

tinued

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Park

etal[70]

Electro

magnetic

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

118

Flatplatetip30times

20c

m2


001016c

m3

582


nsetof

theh

arveste

rrequ

iresthe

load


flutte

ron

setresistance

Lietal[71]

Piezoelectric

cross-flo

wflu

tter

mdash4

mdash0615

8adhereddo

uble-la

yer

stalk72times16times

004

1cm3

130

(i)Cr

oss-flo

wconfi

guratio

ngeneratedon

eorder

ofmagnitude

morep

ower

than

thep

arallel

confi

guratio

n(ii)H

avinghigh

power

density

perw

eightand

per

volume

(iii)Be

ingrobu

stsim

pleandminiature

sized

(iv)B

eing

easy

toblendin

urbanandnatural

environm

entsdu

etoits

ldquoleafrdquoa

ppearance

Deivasig

amaniet

al[72]

Piezoelectric

cross-flo

wflu

tter

Triang

lemdash

mdash00883

8

Isoscelestria

ngletip

8c

min

base8

cmin

height035

mm

inthickn

ess

Stalk72times16times

00205

cm3

00651


lkconfi

guratio

nis

superio

rtotheh

orizon

talstalkwith

fivetim

esmoreo

utpu

tpow

er

Hum

ding

erElectro

magnetic

cross-flo

wflu

tter

mdashmdash

mdashasymp9lowast2

10lowast3

Mem

brane12times07c

m2

Casin

g13times3times25c

m3

0923

(i)Successfu

llypo

wersw

irelesssensor

nodes

(ii)B

eing

compactandrobu

st(iii)Lo


peratio

nal

windspeedrang

e

Hob

ecketal[73]

Piezoelectric

Dual

cantilever

flutte

rmdash

asymp3

mdash0796

asymp13

Twoidentic


00254

cm3

0422

(i)Ve

rywideo

peratio

nalw

indspeedrang

ewith

efficientp

ower

generatio

n(ii)G

eneratingas

ignificantamou

ntof

power

from

3msto

15mswhengapissm

all

lowast1Ca

lculated

by18mwgtimes(015

ms298ms2)2

from


thea

utho

rsof

ther

eference


mthefi

gure

inthed


elt(http

wwwhu

mdingerwindcompdfm

icroBe

lt_briefp

df)


Table6Summaryof

vario

uswakeg

alloping

energy

harvesterd

evices

Author

Transductio

nPrism

shape

Cut-in

wind

speed

(ms)

Cut-o

utwind

speed

(ms)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Jung

andLee

[27]

Electro

magnetic

Circular

cylin

der

asymp12

mdash3704

45

Twoidentic

alcylin

ders5

cmin

dia

85cm

inleng

th

Spacingdistance

5times119863=25

cm

0111

(i)Determiningthep

roper

dista

nceb

etweenthep

arallel

cylin

dersforw

akeg

alloping

energy

harvestin

gas

4-5tim

esthec

ylinderd

iameterthatis

119871119863

=4sim

5(ii)H

ighou

tput

power

(iii)Wideo

peratio

nalw

ind

speedrange

(iv)D

evicev

olum

eistoo

big

Abdelkefi

etal[74]

Piezoelectric

Windw

ard

circular

cylin

der

Leew

ard

square

cylin

der

04

mdash004sim005

305

Circular

cylin

der

125c

min

dia

2715

cmin

leng

th

Square

cylin

der

128times12

8times

2667c

m3

Spacingdistance

24cm

Piezoelectric

two

identic


18times00305

cm3

572times10minus4

(i)Po

wer

from

agalloping

square

cylin

derw

asgreatly

enhanced

bywakee

ffectso

fanup

stream

circular

cylin

der

(ii)O

peratio

nalw

indspeed

rangew

aswidened

bywake

gallo

ping

(iii)Diameter

oftheu

pstre

amcylin

dera

ndthes

pacing

distance

betweentwocylin

dersrequ

irecarefuladjustm

ent


Table7Summaryof

vario

usTIVenergy

harvesterd

evices

Author

Transductio

nCu

t-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Akaydin

etal

[47]

Piezoelectric

asymp5lowast1


11

Bluff

body

3cm

india

12m

inleng

th

Cantilever3times16

times002

cm3

Distance

from

the

wall4c

m

648times10minus8

(i)Perfo

rmance

ofharvesterin

turbulentb

ound

arylayer

depend

sonthed

istance

from

the

walldo

minanto

scillation

frequ

ency

was

close

totheb

eam

resonancefrequ

ency

Hob

eckand

Inman

[28]

Piezoelectric

9sim10lowast2

mdash40

115

Bluff

body

445times

445times1092c

m3

Four

identic

alcantileversin

anarray1016

0mmtimes

2540m

mtimes

1016

0120583m

steel

substratea

ttached

with

4597m

mtimes

2057m

mtimes

15240120583m

PZT

00184

(i)Th

efirstT

IVenergy

harvestin

gmod

elwith

experim

entalvalidation

(ii)B

eing

robu

standsurvivable

duetoits

inherent

redu

ndancy

with

minor

redu

ctionin

total

power

caused

byon

edam

aged

elem

ent

(iii)Suitablefor

high

lyturbulent

fluid

flowenvironm

entslik

estr

eamso

rventilationsyste

ms

lowast1Obtainedfro

mtheinformationof

Figure11of

ther

eference

lowast2Obtainedfro

mtheinformationof

Figure7(b)o

fthe

reference



Author Transduction

Cut-inwindspeed(ms)


Maximumpower(mW)

Windspeed at

max power(ms)

Dimensions


(mWcm3)










40120583m

125 times 10minus5



Z

h

dX

(a)

Lp

L tip

Lb

tp tbBp Bb

(b)










Wind

Bluff body

Inner beam

Outer beam

Magnets


Fixed end







h

U

kh

휃

k휃


























































Wind flows

Substrate

Gallopingenergy

y

L1 L2 L3

x1

x2

x3

harvester

(a)

VIVenergy harvester



(b)


NACA 0012 airfoil


Revolute joint

(c)






ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL


OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n


Vc1











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Table5Summaryof

vario

usflu

ttere

nergyharvesterd

evices

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Bryant

and

Garcia[

63]

Bryant

and

Garcia[

26]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoilprofi

leNAC

A0012

186

mdash22

79

Airfoilsemicho

rd297

cmspan136cm

Ca


00381cm3

717times10minus3

(i)Semiempiric

almod

elof

then

onlin

ear


aerodynamicsyste


ctric

alandmechanical

respon

se

(ii)S

uccessfully

predictsthefl

utterb

ound

arywith

oneo

fthe

realpartso

fthe

firsttwoeigenvalues

turningpo

sitivea

ndthetwoim

aginaryparts

coalescing

(iii)Wideo

peratio

nalw

indspeedrang

e(iv

)Sub

criticalH

opfb

ifurcation

alarge

initial

distu

rbance

isfund

amentalfor

syste

msta

rtup

Bryant

etal[64

]Piezoelectric

Mod

alconvergence

flutte

rFlatplate

Stiff

hoststr

ucture

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

Stiff

host

structure

(i)Com

paredto

astiff

hoststr

ucturea

compliant

hoststr

ucture

redu

cesthe

cut-inwindspeed

cut-infre

quency

andoscillatio

nfre

quency

(ii)Th

epeakpo

wer

isshifted

towardthelow

erwindspeeds

with

thec

ompliant

hoststr

ucture

173

2943

26200

Com

pliant

hoststr

ucture

Com

pliant

hoststr

ucture

152

2935

25163

Bryant

etal[65]

Piezoelectric

Mod

alconvergence

flutte

rFlatplate

173

2943

26

Flatplatetipcho

rd3c

mspan6c

m

thickn

ess0

79m

m


00381cm3

200

(i)Con

firmsthe

feasibilityof

usingam

bientfl

owenergy

harvestin

gto

power

aerodynamiccontrol

surfa

ces

Erturk

etal[66

]Piezoelectric

Mod

alconvergence

flutte

rAirfoil

930

mdash107

930

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

227times10minus3

(i)Eff

ecto


plingon

flutte

renergy

harvestin

gisanalyzed

(ii)F

ound

thattheo

ptim

alload

gave

the

maxim

umflu

tterspeed

duetothea

ssociated

maxim

umshun

tdam

ping

effectd

uringpo

wer

extractio

n

Sousae

tal[67]

Piezoelectric

Mod

alconvergence

flutte

rAirfoil

Linear

confi

guratio

n

Airfoilsemicho

rd125cm

span50

cm

Cantilevermdash

Linear

confi

guratio

n255times10minus3

(i)Th

efreep

layno

nlinearityredu

cesthe

cut-in


utpu

tpow

er

(ii)Th

eoreticallydeterm

iningthattheh

ardening

stiffn

essb

rings

ther

espo

nsea

mplitu

deto


theo

peratio

nal

windspeedrang

e

121

mdash12

121

With

freep

layno

nlinearity

With

freep

lay

nonlinearity

100

mdash27

100

573times10minus3

Bibo

andDaqaq

[68]

Piezoelectric

Mod

alconvergence

flutte

r

Airfoil

profi

leNAC

A0012

23

mdash0138lowast1

3(W

ithbase

acceleratio

n015ms2)

Airfoilsemicho

rd42c

mspan52c

m

Cantilevermdash

838times10minus4

(i)Con

currentfl

owandbase

excitatio

nsenhances

power

generatio

nperfo

rmance

(ii)C

oncurrentexcitatio

nsincreaseso

utpu

tpo

wer

by25tim

esbelowthefl

utterspeedand

over

3tim

esabovethe

flutte

rspeed

(iii)Ab

ovethe

flutte

rspeedrequirin

gcareful

adjustm

entb

ecause

power

issensitive

tobase

acceleratio

nfre

quency

Kwon

[69]

Piezoelectric

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

40

15

Flatplatetip60times

30c

m2


002

cm3

256

(i)SimpleT

-shape

structureeasyto

fabricate

(ii)N

orotatin

gcompo

nents

(iii)Wideo

peratio

nalw

indspeedrang

e


Table5Con

tinued

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Park

etal[70]

Electro

magnetic

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

118

Flatplatetip30times

20c

m2


001016c

m3

582


nsetof

theh

arveste

rrequ

iresthe

load


flutte

ron

setresistance

Lietal[71]

Piezoelectric

cross-flo

wflu

tter

mdash4

mdash0615

8adhereddo

uble-la

yer

stalk72times16times

004

1cm3

130

(i)Cr

oss-flo

wconfi

guratio

ngeneratedon

eorder

ofmagnitude

morep

ower

than

thep

arallel

confi

guratio

n(ii)H

avinghigh

power

density

perw

eightand

per

volume

(iii)Be

ingrobu

stsim

pleandminiature

sized

(iv)B

eing

easy

toblendin

urbanandnatural

environm

entsdu

etoits

ldquoleafrdquoa

ppearance

Deivasig

amaniet

al[72]

Piezoelectric

cross-flo

wflu

tter

Triang

lemdash

mdash00883

8

Isoscelestria

ngletip

8c

min

base8

cmin

height035

mm

inthickn

ess

Stalk72times16times

00205

cm3

00651


lkconfi

guratio

nis

superio

rtotheh

orizon

talstalkwith

fivetim

esmoreo

utpu

tpow

er

Hum

ding

erElectro

magnetic

cross-flo

wflu

tter

mdashmdash

mdashasymp9lowast2

10lowast3

Mem

brane12times07c

m2

Casin

g13times3times25c

m3

0923

(i)Successfu

llypo

wersw

irelesssensor

nodes

(ii)B

eing

compactandrobu

st(iii)Lo


peratio

nal

windspeedrang

e

Hob

ecketal[73]

Piezoelectric

Dual

cantilever

flutte

rmdash

asymp3

mdash0796

asymp13

Twoidentic


00254

cm3

0422

(i)Ve

rywideo

peratio

nalw

indspeedrang

ewith

efficientp

ower

generatio

n(ii)G

eneratingas

ignificantamou

ntof

power

from

3msto

15mswhengapissm

all

lowast1Ca

lculated

by18mwgtimes(015

ms298ms2)2

from


thea

utho

rsof

ther

eference


mthefi

gure

inthed


elt(http

wwwhu

mdingerwindcompdfm

icroBe

lt_briefp

df)


Table6Summaryof

vario

uswakeg

alloping

energy

harvesterd

evices

Author

Transductio

nPrism

shape

Cut-in

wind

speed

(ms)

Cut-o

utwind

speed

(ms)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Jung

andLee

[27]

Electro

magnetic

Circular

cylin

der

asymp12

mdash3704

45

Twoidentic

alcylin

ders5

cmin

dia

85cm

inleng

th

Spacingdistance

5times119863=25

cm

0111

(i)Determiningthep

roper

dista

nceb

etweenthep

arallel

cylin

dersforw

akeg

alloping

energy

harvestin

gas

4-5tim

esthec

ylinderd

iameterthatis

119871119863

=4sim

5(ii)H

ighou

tput

power

(iii)Wideo

peratio

nalw

ind

speedrange

(iv)D

evicev

olum

eistoo

big

Abdelkefi

etal[74]

Piezoelectric

Windw

ard

circular

cylin

der

Leew

ard

square

cylin

der

04

mdash004sim005

305

Circular

cylin

der

125c

min

dia

2715

cmin

leng

th

Square

cylin

der

128times12

8times

2667c

m3

Spacingdistance

24cm

Piezoelectric

two

identic


18times00305

cm3

572times10minus4

(i)Po

wer

from

agalloping

square

cylin

derw

asgreatly

enhanced

bywakee

ffectso

fanup

stream

circular

cylin

der

(ii)O

peratio

nalw

indspeed

rangew

aswidened

bywake

gallo

ping

(iii)Diameter

oftheu

pstre

amcylin

dera

ndthes

pacing

distance

betweentwocylin

dersrequ

irecarefuladjustm

ent


Table7Summaryof

vario

usTIVenergy

harvesterd

evices

Author

Transductio

nCu

t-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Akaydin

etal

[47]

Piezoelectric

asymp5lowast1


11

Bluff

body

3cm

india

12m

inleng

th

Cantilever3times16

times002

cm3

Distance

from

the

wall4c

m

648times10minus8

(i)Perfo

rmance

ofharvesterin

turbulentb

ound

arylayer

depend

sonthed

istance

from

the

walldo

minanto

scillation

frequ

ency

was

close

totheb

eam

resonancefrequ

ency

Hob

eckand

Inman

[28]

Piezoelectric

9sim10lowast2

mdash40

115

Bluff

body

445times

445times1092c

m3

Four

identic

alcantileversin

anarray1016

0mmtimes

2540m

mtimes

1016

0120583m

steel

substratea

ttached

with

4597m

mtimes

2057m

mtimes

15240120583m

PZT

00184

(i)Th

efirstT

IVenergy

harvestin

gmod

elwith

experim

entalvalidation

(ii)B

eing

robu

standsurvivable

duetoits

inherent

redu

ndancy

with

minor

redu

ctionin

total

power

caused

byon

edam

aged

elem

ent

(iii)Suitablefor

high

lyturbulent

fluid

flowenvironm

entslik

estr

eamso

rventilationsyste

ms

lowast1Obtainedfro

mtheinformationof

Figure11of

ther

eference

lowast2Obtainedfro

mtheinformationof

Figure7(b)o

fthe

reference



Author Transduction

Cut-inwindspeed(ms)


Maximumpower(mW)

Windspeed at

max power(ms)

Dimensions


(mWcm3)










40120583m

125 times 10minus5



Z

h

dX

(a)

Lp

L tip

Lb

tp tbBp Bb

(b)










Wind

Bluff body

Inner beam

Outer beam

Magnets


Fixed end







h

U

kh

휃

k휃


























































Wind flows

Substrate

Gallopingenergy

y

L1 L2 L3

x1

x2

x3

harvester

(a)

VIVenergy harvester



(b)


NACA 0012 airfoil


Revolute joint

(c)






ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL


OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n


Vc1











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Table5Con

tinued

Author

Transductio

nFlutter

insta

bility

Flap

atthetip

Cut-inwind

speed(flutter

speed)

(ms)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeedat

max

power

(ms)

Dim

ensio

nsPo

wer

density

perv

olum

e(m

Wcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Park

etal[70]

Electro

magnetic

Mod

alconvergence

flutte

r

Flatplatetip

Who

ledevice

T-shape

4mdash

118

Flatplatetip30times

20c

m2


001016c

m3

582


nsetof

theh

arveste

rrequ

iresthe

load


flutte

ron

setresistance

Lietal[71]

Piezoelectric

cross-flo

wflu

tter

mdash4

mdash0615

8adhereddo

uble-la

yer

stalk72times16times

004

1cm3

130

(i)Cr

oss-flo

wconfi

guratio

ngeneratedon

eorder

ofmagnitude

morep

ower

than

thep

arallel

confi

guratio

n(ii)H

avinghigh

power

density

perw

eightand

per

volume

(iii)Be

ingrobu

stsim

pleandminiature

sized

(iv)B

eing

easy

toblendin

urbanandnatural

environm

entsdu

etoits

ldquoleafrdquoa

ppearance

Deivasig

amaniet

al[72]

Piezoelectric

cross-flo

wflu

tter

Triang

lemdash

mdash00883

8

Isoscelestria

ngletip

8c

min

base8

cmin

height035

mm

inthickn

ess

Stalk72times16times

00205

cm3

00651


lkconfi

guratio

nis

superio

rtotheh

orizon

talstalkwith

fivetim

esmoreo

utpu

tpow

er

Hum

ding

erElectro

magnetic

cross-flo

wflu

tter

mdashmdash

mdashasymp9lowast2

10lowast3

Mem

brane12times07c

m2

Casin

g13times3times25c

m3

0923

(i)Successfu

llypo

wersw

irelesssensor

nodes

(ii)B

eing

compactandrobu

st(iii)Lo


peratio

nal

windspeedrang

e

Hob

ecketal[73]

Piezoelectric

Dual

cantilever

flutte

rmdash

asymp3

mdash0796

asymp13

Twoidentic


00254

cm3

0422

(i)Ve

rywideo

peratio

nalw

indspeedrang

ewith

efficientp

ower

generatio

n(ii)G

eneratingas

ignificantamou

ntof

power

from

3msto

15mswhengapissm

all

lowast1Ca

lculated

by18mwgtimes(015

ms298ms2)2

from


thea

utho

rsof

ther

eference


mthefi

gure

inthed


elt(http

wwwhu

mdingerwindcompdfm

icroBe

lt_briefp

df)


Table6Summaryof

vario

uswakeg

alloping

energy

harvesterd

evices

Author

Transductio

nPrism

shape

Cut-in

wind

speed

(ms)

Cut-o

utwind

speed

(ms)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Jung

andLee

[27]

Electro

magnetic

Circular

cylin

der

asymp12

mdash3704

45

Twoidentic

alcylin

ders5

cmin

dia

85cm

inleng

th

Spacingdistance

5times119863=25

cm

0111

(i)Determiningthep

roper

dista

nceb

etweenthep

arallel

cylin

dersforw

akeg

alloping

energy

harvestin

gas

4-5tim

esthec

ylinderd

iameterthatis

119871119863

=4sim

5(ii)H

ighou

tput

power

(iii)Wideo

peratio

nalw

ind

speedrange

(iv)D

evicev

olum

eistoo

big

Abdelkefi

etal[74]

Piezoelectric

Windw

ard

circular

cylin

der

Leew

ard

square

cylin

der

04

mdash004sim005

305

Circular

cylin

der

125c

min

dia

2715

cmin

leng

th

Square

cylin

der

128times12

8times

2667c

m3

Spacingdistance

24cm

Piezoelectric

two

identic


18times00305

cm3

572times10minus4

(i)Po

wer

from

agalloping

square

cylin

derw

asgreatly

enhanced

bywakee

ffectso

fanup

stream

circular

cylin

der

(ii)O

peratio

nalw

indspeed

rangew

aswidened

bywake

gallo

ping

(iii)Diameter

oftheu

pstre

amcylin

dera

ndthes

pacing

distance

betweentwocylin

dersrequ

irecarefuladjustm

ent


Table7Summaryof

vario

usTIVenergy

harvesterd

evices

Author

Transductio

nCu

t-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Akaydin

etal

[47]

Piezoelectric

asymp5lowast1


11

Bluff

body

3cm

india

12m

inleng

th

Cantilever3times16

times002

cm3

Distance

from

the

wall4c

m

648times10minus8

(i)Perfo

rmance

ofharvesterin

turbulentb

ound

arylayer

depend

sonthed

istance

from

the

walldo

minanto

scillation

frequ

ency

was

close

totheb

eam

resonancefrequ

ency

Hob

eckand

Inman

[28]

Piezoelectric

9sim10lowast2

mdash40

115

Bluff

body

445times

445times1092c

m3

Four

identic

alcantileversin

anarray1016

0mmtimes

2540m

mtimes

1016

0120583m

steel

substratea

ttached

with

4597m

mtimes

2057m

mtimes

15240120583m

PZT

00184

(i)Th

efirstT

IVenergy

harvestin

gmod

elwith

experim

entalvalidation

(ii)B

eing

robu

standsurvivable

duetoits

inherent

redu

ndancy

with

minor

redu

ctionin

total

power

caused

byon

edam

aged

elem

ent

(iii)Suitablefor

high

lyturbulent

fluid

flowenvironm

entslik

estr

eamso

rventilationsyste

ms

lowast1Obtainedfro

mtheinformationof

Figure11of

ther

eference

lowast2Obtainedfro

mtheinformationof

Figure7(b)o

fthe

reference



Author Transduction

Cut-inwindspeed(ms)


Maximumpower(mW)

Windspeed at

max power(ms)

Dimensions


(mWcm3)










40120583m

125 times 10minus5



Z

h

dX

(a)

Lp

L tip

Lb

tp tbBp Bb

(b)










Wind

Bluff body

Inner beam

Outer beam

Magnets


Fixed end







h

U

kh

휃

k휃


























































Wind flows

Substrate

Gallopingenergy

y

L1 L2 L3

x1

x2

x3

harvester

(a)

VIVenergy harvester



(b)


NACA 0012 airfoil


Revolute joint

(c)






ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL


OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n


Vc1











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Table6Summaryof

vario

uswakeg

alloping

energy

harvesterd

evices

Author

Transductio

nPrism

shape

Cut-in

wind

speed

(ms)

Cut-o

utwind

speed

(ms)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Jung

andLee

[27]

Electro

magnetic

Circular

cylin

der

asymp12

mdash3704

45

Twoidentic

alcylin

ders5

cmin

dia

85cm

inleng

th

Spacingdistance

5times119863=25

cm

0111

(i)Determiningthep

roper

dista

nceb

etweenthep

arallel

cylin

dersforw

akeg

alloping

energy

harvestin

gas

4-5tim

esthec

ylinderd

iameterthatis

119871119863

=4sim

5(ii)H

ighou

tput

power

(iii)Wideo

peratio

nalw

ind

speedrange

(iv)D

evicev

olum

eistoo

big

Abdelkefi

etal[74]

Piezoelectric

Windw

ard

circular

cylin

der

Leew

ard

square

cylin

der

04

mdash004sim005

305

Circular

cylin

der

125c

min

dia

2715

cmin

leng

th

Square

cylin

der

128times12

8times

2667c

m3

Spacingdistance

24cm

Piezoelectric

two

identic


18times00305

cm3

572times10minus4

(i)Po

wer

from

agalloping

square

cylin

derw

asgreatly

enhanced

bywakee

ffectso

fanup

stream

circular

cylin

der

(ii)O

peratio

nalw

indspeed

rangew

aswidened

bywake

gallo

ping

(iii)Diameter

oftheu

pstre

amcylin

dera

ndthes

pacing

distance

betweentwocylin

dersrequ

irecarefuladjustm

ent


Table7Summaryof

vario

usTIVenergy

harvesterd

evices

Author

Transductio

nCu

t-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Akaydin

etal

[47]

Piezoelectric

asymp5lowast1


11

Bluff

body

3cm

india

12m

inleng

th

Cantilever3times16

times002

cm3

Distance

from

the

wall4c

m

648times10minus8

(i)Perfo

rmance

ofharvesterin

turbulentb

ound

arylayer

depend

sonthed

istance

from

the

walldo

minanto

scillation

frequ

ency

was

close

totheb

eam

resonancefrequ

ency

Hob

eckand

Inman

[28]

Piezoelectric

9sim10lowast2

mdash40

115

Bluff

body

445times

445times1092c

m3

Four

identic

alcantileversin

anarray1016

0mmtimes

2540m

mtimes

1016

0120583m

steel

substratea

ttached

with

4597m

mtimes

2057m

mtimes

15240120583m

PZT

00184

(i)Th

efirstT

IVenergy

harvestin

gmod

elwith

experim

entalvalidation

(ii)B

eing

robu

standsurvivable

duetoits

inherent

redu

ndancy

with

minor

redu

ctionin

total

power

caused

byon

edam

aged

elem

ent

(iii)Suitablefor

high

lyturbulent

fluid

flowenvironm

entslik

estr

eamso

rventilationsyste

ms

lowast1Obtainedfro

mtheinformationof

Figure11of

ther

eference

lowast2Obtainedfro

mtheinformationof

Figure7(b)o

fthe

reference



Author Transduction

Cut-inwindspeed(ms)


Maximumpower(mW)

Windspeed at

max power(ms)

Dimensions


(mWcm3)










40120583m

125 times 10minus5



Z

h

dX

(a)

Lp

L tip

Lb

tp tbBp Bb

(b)










Wind

Bluff body

Inner beam

Outer beam

Magnets


Fixed end







h

U

kh

휃

k휃


























































Wind flows

Substrate

Gallopingenergy

y

L1 L2 L3

x1

x2

x3

harvester

(a)

VIVenergy harvester



(b)


NACA 0012 airfoil


Revolute joint

(c)






ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL


OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n


Vc1











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Table7Summaryof

vario

usTIVenergy

harvesterd

evices

Author

Transductio

nCu

t-inwind

speed(m

s)

Cut-o

utwind

speed(m

s)

Maxim

umpo

wer

(mW)

Windspeed

atmax

power

(ms)

Dim

ensio

ns

Power

density

per

volume

(mWcm3)

Advantagesdisa

dvantagesa

ndotherinformation

Akaydin

etal

[47]

Piezoelectric

asymp5lowast1


11

Bluff

body

3cm

india

12m

inleng

th

Cantilever3times16

times002

cm3

Distance

from

the

wall4c

m

648times10minus8

(i)Perfo

rmance

ofharvesterin

turbulentb

ound

arylayer

depend

sonthed

istance

from

the

walldo

minanto

scillation

frequ

ency

was

close

totheb

eam

resonancefrequ

ency

Hob

eckand

Inman

[28]

Piezoelectric

9sim10lowast2

mdash40

115

Bluff

body

445times

445times1092c

m3

Four

identic

alcantileversin

anarray1016

0mmtimes

2540m

mtimes

1016

0120583m

steel

substratea

ttached

with

4597m

mtimes

2057m

mtimes

15240120583m

PZT

00184

(i)Th

efirstT

IVenergy

harvestin

gmod

elwith

experim

entalvalidation

(ii)B

eing

robu

standsurvivable

duetoits

inherent

redu

ndancy

with

minor

redu

ctionin

total

power

caused

byon

edam

aged

elem

ent

(iii)Suitablefor

high

lyturbulent

fluid

flowenvironm

entslik

estr

eamso

rventilationsyste

ms

lowast1Obtainedfro

mtheinformationof

Figure11of

ther

eference

lowast2Obtainedfro

mtheinformationof

Figure7(b)o

fthe

reference



Author Transduction

Cut-inwindspeed(ms)


Maximumpower(mW)

Windspeed at

max power(ms)

Dimensions


(mWcm3)










40120583m

125 times 10minus5



Z

h

dX

(a)

Lp

L tip

Lb

tp tbBp Bb

(b)










Wind

Bluff body

Inner beam

Outer beam

Magnets


Fixed end







h

U

kh

휃

k휃


























































Wind flows

Substrate

Gallopingenergy

y

L1 L2 L3

x1

x2

x3

harvester

(a)

VIVenergy harvester



(b)


NACA 0012 airfoil


Revolute joint

(c)






ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL


OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n


Vc1











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











Author Transduction

Cut-inwindspeed(ms)


Maximumpower(mW)

Windspeed at

max power(ms)

Dimensions


(mWcm3)










40120583m

125 times 10minus5



Z

h

dX

(a)

Lp

L tip

Lb

tp tbBp Bb

(b)










Wind

Bluff body

Inner beam

Outer beam

Magnets


Fixed end







h

U

kh

휃

k휃


























































Wind flows

Substrate

Gallopingenergy

y

L1 L2 L3

x1

x2

x3

harvester

(a)

VIVenergy harvester



(b)


NACA 0012 airfoil


Revolute joint

(c)






ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL


OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n


Vc1











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation













Wind

Bluff body

Inner beam

Outer beam

Magnets


Fixed end







h

U

kh

휃

k휃


























































Wind flows

Substrate

Gallopingenergy

y

L1 L2 L3

x1

x2

x3

harvester

(a)

VIVenergy harvester



(b)


NACA 0012 airfoil


Revolute joint

(c)






ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL


OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n


Vc1











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










h

U

kh

휃

k휃


























































Wind flows

Substrate

Gallopingenergy

y

L1 L2 L3

x1

x2

x3

harvester

(a)

VIVenergy harvester



(b)


NACA 0012 airfoil


Revolute joint

(c)






ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL


OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n


Vc1











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation



























































Wind flows

Substrate

Gallopingenergy

y

L1 L2 L3

x1

x2

x3

harvester

(a)

VIVenergy harvester



(b)


NACA 0012 airfoil


Revolute joint

(c)






ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL


OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n


Vc1











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










ARB1

I(iin)

TX1 Q2N2222Q2N2904

IDEAL IDEAL

IDEALIDEALIDEAL

IDEAL IDEAL

IDEAL


OUTN

OUTP

inb

ina

L2

L1

C3R3

R2

R4

R1

1k

1k

Cp

Vp

600k

200k

10u RL

D1

C1

P1 S1

D8D6

D7D9

D4

D2

D3

Q1

Q2

Cf

47m

IC = 100u316819m2783m 652m

257n

2n


Vc1











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











Signal for sensing

Comparator

Bridge rectifier


Fixed

Fixed

MicaZ Mote

Antenna

B+ Bminus

C+ Cminus

Air flow

Bimorph(harvester)

Unimorph(sensor)

Bluff body


circuit

GND

DC-DCconvertor

connector

A

Power

LED

s


Analog IOInterrupt

CC2420 radio

minus++

Vin Vout

51-p

in ex

pans

ion

conn

ecto

r




5 Conclusions







References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation













References




















































































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation



























































































































































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation









toward small-scale wind energy harvesting: design,...

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