Micro Energy Harvesting Power Supply for … Energy Harvesting Power Supply for Distributed and Embedded Systems ... piezo disk piezo disk cured ... sound and vibration flow heat pressure

Sheet 1Philipp Bingger, Peter Woias, Effiziente Elekronik, 1.12.2009

Micro Energy HarvestingPower Supply for Distributed and Embedded Systems

Philipp Bingger and Peter Woias

Albert-Ludwig-University of FreiburgDepartment of Microsystems Engineering (IMTEK)

Laboratory for Design of MicrosystemsFreiburg, Germany


WireWire oror batterybattery …… oror whatwhat ??

Sensors in redwood trees© University of California

medical implants© Vitatron

distributed and „embedded“ sensorsystems in greenhouses © Crossbow

tire pressure sensors

sensor

rope

battery service person(vertigo-proof)


energyconversion

materialsand

energystorage

energy andsystem

management

Micro Energy Harvesting: The VisionMicro Energy Harvesting: The Vision

heat,light

movement,other bugs,…

Energy-Autonomous Embedded Systems„always on“no battery recharging or exchangeno power cordseasy to install …… at numerous application sites

energy management

micro-sensor

wirelesstransmitter

sensor input

micro-controller

wireless data link

generator energy storage


Micro Micro energyenergy harvestingharvesting –– IMTEKIMTEK‘‘ss PhDPhD programprogram

Fact sheetfinanced by DFG and industry3 associated members22+1 PhD scholarhips

start: October 2006run-time: 4.5 years (1st phase)

Associated Members Members Sponsors

Research topicsenergy transduction mechanismsmaterials for energy harvestingenergy storage and managementsystem considerations


PiezoelectricPiezoelectric bendingbending generatorsgenerators: : PrinciplePrinciple

11,31 piezodq σ⋅= ( )1131 σ⋅== dtd

dtdqdI

Design challengeshomogeneous mechanical stress higher output powertunable resonance frequency broader application range, more powersmart system integration cheaper, easier fabrication


OptimizedOptimized vibrationalvibrational piezopiezo generatorgenerator (2007)(2007)

spectral output power (no seismic mass) influence of a seismic mass

E. Just et al., Proc. GMM-Workshop “Energieautarke Mikrosysteme”, 2006

F. Goldschmidtböing, P. Woias, Journ. Micromech. Microeng. 18, 2008, 104013


FrequencyFrequency--tunabletunable piezopiezo generatorgenerator (2008)(2008)

PrincipleActuation force in the „arms“ will stiffen the resonating beam and thus change its resonance frequency

high tuning range (22%)loss of Q factor withincreasing force

C. Eichhorn et al., Proc. PowerMEMS 2008, Sendai, Japan, 309-312.

force


FabricationFabrication: : PiezoPiezo--PolymerPolymer--CompositesComposites (2003)(2003)

vent

molding form

piezodisk

piezo disk cured polymer

molding form

liquidthermosettingpolymer

feed

Advantagesstructure definition and piezo integrationin one single steplow-cost perspective via inject moldingextremely high design flexibilityactuators and generators in one single technology

20 mm

piezoceramic diskwith metal electrodes

electrical contact

polymer layer

mounting block

seismic massvibration


ImpactImpact--typetype piezopiezo generatorgenerator (2005)(2005)

Advantagesstress-homogenized hinge designfor a maximal output powerhigh output powerhigh output voltagestacked devices for power multiplication

6 mWp @ 36N pulse (100 ms)

M. Wischke et al., Proc. Transducers 2007, Lyon, France, 875-878.


ElectromagneticElectromagnetic generatorsgenerators: : PrinciplePrinciple and and examplesexamples

multi-resonant generatorUniv. Hongkong, 2002

P = 800 µWtd

dNU Φ⋅−=

rotatory generator of the Seiko KineticTM wrist watch

P = 5 µW

rotor

generator

batteryelectromechanicquartz clockwork

PropertiesAC currents from motion or induced AC fieldsbad to fair voltage range (mV…V)moderate source impedance (<10 kΩ)


ElectromagneticElectromagnetic generatorgenerator in PCB technologyin PCB technology

multi-resonant generatorUniv. Hongkong, 2002

lid

wire-woundcoil

permanentmagnet

spacer

mechanicalresonator

22 mm

Propertiesoutput power: 330 µW @ 102 Hz and 1Gno-load voltage: 210 mV(improved via modified coil design)

E. Bouendeu, J. Korvink, IMTEK – Laboratory for Simulation


ThermoelectricThermoelectric generatorsgenerators (TEG): (TEG): PrinciplePrinciple

relevant material combinations α [µV/K]

Al / p-Poly-Si 195Al / n-Poly-Si 110p-Poly-Si / n-Poly-Si 190...320p-Bi0,5Sb1,5Te3 / n-Bi0,87Sb0,13 200...420

TU Δ⋅=Δ α

2TAPp electric

Δ⋅=

Seebeck voltage

Specific output power


ThermoelectricThermoelectric generatorsgenerators: : ExamplesExamples

Micro Peltier cooler (photo) and micro-TEG (SEM) © FhG-IPM, MicroPelt

micro-TEG from (1994) for the „Seiko Thermic“(sold in small numbers from 1998 on)

micro-TEG in planar CMOS © Infineon, 2003

polysiliconFOX

cavity

polysilicon

oxidesilicon substrate

cavity

P = 3 µW/cm² @ ΔT = 1..3 K

P = 1 µW/cm² @ ΔT = 5 K


3D 3D micromicro--TEGTEG

Output power and no-load voltage @ 10Kmeasured: 1.612 µW

6 V optimization potential: 36.3 µW

top heat conductor (gold)

bottom heat conductor (silicon)

membrane with planarthermocouples (Al-poly-Si)

thermal insulator (SU-8)

air chamber for thermal insulation

T. Huesgen et al., Sensors & Actuators A 145-146, 2008, 523-429.

10 m

m

7500 thermocouples


Bio Bio fuelfuel cellscells: : PrinciplePrinciple and and applicationapplication

direct-oxidizingglucose fuel cell

S. Kerzenmacher et al., Journ. Power Sources, 2008A. Kloke et al., Proc. Biosensors 2008, Shanghai

Propertiesoutput power: 2.3 … 3.3 µW /cm²open cell voltage: 0.5 … 0.3 Vpower requirement of a pacemaker: 10 µW

0,0

0,2

0,4

0,6

0,8

1,0

1,2

0 5 10Current density in µA cm-2

Cel

l pot

entia

l in

V

0,0

0,5

1,0

1,5

2,0

2,5

3,0

Pow

er d

ensi

ty in

µW

cm

-2

pacemaker


Energy Energy densitiesdensities of of variousvarious storagestorage conceptsconcepts

high storage density of H2 in MHacceptable (and improving) efficiency of H2 fuel cells

Would a „hydrogen battery“make sense ?

0

20

40

60

80

100

Fara

day

effic

ienc

y [%

]

Gold

Cap

Ni-M

H

Li-Io

nH2

fuel

cell

Elec

trolyz

er

Gold Cap

Lead Acid

Adenosine Triphosphate

NiMHLi-Ion

H2 in MH (< 2%)

H2 in MH (4%)

H2 in MH (nanopowder) Methanol

Electrolyte Cap.

1

10

100

1.000

10.000

1 10 100 1.000 10.000

energy density in [Wh/kg]

ener

gy d

ensi

ty in

[Wh/

l]

hydrogen in metal hydrides (MH)

batteries

capacitors

Refs: J. Brodd et al, J. Electrochem. Soc., 151 (3), 2004, K1-K11 and HERA Hydrogen Storage Solutions, Germany


chip-integratedfuel cell with Pd storage

HydrogenHydrogen--basedbased energyenergy storagestorage

G. Erdler, M. Frank, M. Lehmann, H. Reinecke, C. Mueller, Sensors & Actuators A 132/1 (2006), 331-336.

volta

ge[V

]

current density [mA/cm²]

pow

er d

ensi

ty[m

W/c

m²]

0.5 mm thick fuel cell:photograph (right) and

its electrical characteristics

6 mm6 mm

19 mm19 mm


Energy Energy managementmanagement

Requirementsstart-up controloptimal impedance match betweengenerator, battery and loadvoltage level transformationactive generator controlactive rectificationsupply voltage: < 1 Vpower consumption: a few µW

Solutions, chips ? ….not available today

(2004).

2163 µm

control ASIC for a capacitivemicro converter, Medinger,

Ph. D. thesis, MIT, andAnalog Devices, 1999

….eventuallycoming along

(2009)

Solutions, microchips ?..... not availabletoday ( 2005).


Commercial Commercial lowlow voltagevoltage stepstep--upup convertersconverters

0

0,5

1

1,5

2

2,5

3

1970 1980 1990 2000 2010year

star

t-up

volta

ge [V

]

2005: 0.3 Vphotovoltaic cell, TE generator

1998: 1.0 V

charge pumpsinductor-based


sensor system

Temperaturesensor

Micro-controller

Energy managementand storage

RF transmitter

Application szenario:

Remote temperaturesensing at „heavy“machinery …

DemonstratorDemonstrator: : RemoteRemote TemperatureTemperature MonitoringMonitoring

Vibration

Temperature ?

Energy-autonomous

Piezogenerator

RF receiver

35,4 °C

35,4 °C


System System setset--upup

Requirementswell-defined turn-on and turn-offlow-voltage operationlow-power operation


StackedStacked impactimpact--typetype piezogeneratorpiezogenerator

Technical datamaximum output power: 120 µWoptimal output voltage: 2.15 Vtolerance band: ± 0.2 V


LowLow--voltagevoltage regulatorregulator withwith sharpsharp turnturn--onon

Characteristicssafe-operation supply voltage: 0.4 V ☺max. power consumption: 25 µWoptimization potential:1…3 µW ☺


WhyWhy notnot buybuy …… ??

Problems with today‘s ICsno „real low voltage“undefined sub-thresholdbehaviourlimited functionality (notspecific for energy harvesting)


Micro-Embedded Systems and Micro Energy Harvesting

What is it good for ?


Automotive Automotive applicationsapplications

engine temperature sensorsair flow sensorsknock sensorstire rotation sensors….solar-powered air conditioningenergy recovery from hot exhaust gases © Alps

lightmotion

accelerationsound and vibration

flowheat

pressuresensor

© Continental


Tire pressure monitoring Tire pressure monitoring -- PiezotagPiezotag

mounted opposite the tread power generator (piezoelectric)power management (rectify and smooth)electronics, sensors (p,T) and RF transmitter works at speeds above 15 km/h test 40,000 km → OK

© Piezotag Ltd, England, 2009

Tire Pressure Monitoring Systems

(TPMS)


Home and building automationHome and building automation

heat meters at radiatorsautonomous temperature sensorsautonomous lighting sensorsdoor and window surveillanceroom occupancy detection via footstep detectorsventilation control…

autonomous switch © enOcean

lightheat/cold

sound and vibrationflow


AISISAISIS--Project (BMBF)Project (BMBF)

Project goalsenergy-autonomous sensor-system for tunnels to determine the damage in case of (explosion, fire,…)energy-harvesting-methods(piezoelectric, thermoelectric, wireless energy transmission )development of high-tensile building materials development of evaluation-models psychological research

project leadership:

5 cm


AISISAISIS--Project (BMBF)Project (BMBF)

thermoelectric-conceptgenerator inside tunnel-wallsmall temperature gradients(ΔT = 2 K)optimized thermal coupling

vibration transducer-conceptgenerator on tunnel-wallmechanical → electrical conversionmulti-resonant transducer with optimized mechanical couplingpiezoelectric or electromagnetic

© IMTEK, Germany, 2009


„„Daily Daily LivingLiving““, , medicalmedical, , wellnesswellness, , sportssports,,……

forcemovement

flowchem. energy

heat

© Microstrain

stress-controlled prosthesesautonomous sensors and implants (Retina, Cochlear,…) patient monitoring (downfall, faint,…)autonomous sports equipment,…


„„ParasiticParasitic““ biomechanicalbiomechanical generatorsgenerators

MIT Media Lab, Boston, USA, 1998

P = 0,25 W© Bionic Power

Burnaby, Canada, 2008P = 5 W

P = 3 W

© Bosch, ca. 1930


© Martijn Pater, TU Delft, NL, 2000„Pullman“ MP3-Player

© Chris Aimone and Tomek Bartczak, Toronto, Canada, 2003

„REGEN“ MP3-Player

© Freeplay Energy, UK, 2003crank-powered radio

NonNon--parasiticparasitic““ biomechanicalbiomechanical generatorsgenerators


First micro energy harvesters available

Power management system MUST be adapted to the particular generator

Need for low power ICs for power management Well-defined turn-on and turn-offSafe-operationLow power consumption

Conclusion and outlook

Medinger, 1999


Thank you verymuch for your

attention !

Documents

Micro Energy Harvesting Power Supply for … Energy Harvesting Power Supply for Distributed and Embedded Systems ... piezo disk piezo disk cured ... sound and vibration flow heat pressure