Ubiquitous Electronics: Why Now?

0.01

0.1

1

10

100

1000

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1973

1981

1987

1995

1997

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2003

2005

2007

Year

Dol

lars

per

Meg

abit

mem

ory

0

200

400

600

800

1000

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Mill

ions

of T

rans

istor

s per

Per

sonCost per megabit

Transistors per Person

20% Consumer

29% Consumer

39% Consumer

Form Factor

Lim

iting Consum

er Grow

th

Flexible Displays (TV)Intelligent ClothingWearable computingAutonomous Homes

BroadbandInternet

Cell PhonesPersonalComputer

VideoRecorders

Future Drivers

Ubiquitous ElectronicsDeveloping Technology

Organic Optoelectronics• Tunable electronic properties, ease of processing• Extend current range of semiconductors• Under development for displays, logic and lighting

Flexible Displays

Radio Frequency ID (smart) Tags

• Truly wearable computer interface • Several different technologies still compete• Major technological obstacles to overcome

• Can be placed practically anywhere• Will revolutionize tracking & inventory• Major economic impact• Currently too expensive

Ubiquitous ElectronicsChallenges

Nascent technology• Competing paradigms (silicon, organics)• Spans wide range of materials and processing• Future technology path undecided• Innovative, integrative training needed

• Compatibility with commodity materials (plastic, paper, textiles,…)

• Low-cost manufacturing(print electronic circuits like a newspaper)

• Environmental friendliness(starting materials, manufacturing, finalproduct must be green)

Ubiquitous Electronics:Challenges

Technology PlatformLarge-area organic light emitting diodes for lighting

Patterning the organicand the metals

Plastic substrates andencapsulation

Imaging of devicefunctions

Efficient light-emittingcoatings

Technology PlatformOrganic transistors for smart RF-ID tags

Patterning of variousmaterials

Characterization of devicefunctions

Plastic substrates andencapsulation

Growth of crystallineorganic films

Polymeric Substrates• flexibility• robustness• conducive to roll-to-roll manufacturing

– ultimate method for delivering low cost

• For roll-to-roll manufacturing polymeric substrates need tobe significantly improved in

• dimensional stability• barrier properties to oxygen and water• surface adhesion to both organic, inorganic and metallic

layers• free from contaminants/surface and internal defects

Polymer Substrates

• Polyethylene terephthalate (PET)• Polyethylene naphthalate (PEN)

• Polycarbonate (PC)• Polyethersulfone (PES)• Polycyclic Olefin (PCO)• Polyimide (PI)

350-220150200150Use TºC

2315083NA275225Strength(MPa)

2.51.92.21.76.15.3E (GPa)

1.8.031.40.2-0.40.140.14Water(%)

Y9190>90>85>85Tr(%)

177454601315CTEppm/ºC

PIPCOPESPCPENPET

Barrier Layers• development of effective, high performance

barrier materials has been one of the criticaltechnology hurdles in the manufacture andcommercial development of flexible electronics

• barrier layers protect organic circuit elementsagainst moisture and oxygen– barrier layers need to be

• impermeable• mechanically flexible• optically transparent• chemically resistant• adhere well to the substrate.

Permeability of Oxygen

• PET: 10-9 cm2/sec @ 20 °C

• SiO2: 10-15 cm2/sec @ 1500 °C

Evaporation0.50.5PET/Al

Evaporation12PET/SiOx

1180PET

MethodWVTRg/m2

per day

OTRcm3/m2

per day per atm

Nanotechnology to the rescue?Nanotechnology to the rescue?

Why Care About Why Care About NanoNano??

Little word with big potential Speculation about a seismic shift in science and

engineering Implications in ethics, economics, day-to-day life Panacea for all ills? Next Industrial Revolution? Next step in biological & chemical warfare? Opportunity to create next species to replace humanity?

M. Ratner and D. Ratner “Nanotechnology: A Gentle Introductionto the Next Big Idea” Prentice Hall, 2003

So What?So What?

Nanoscale is unique because macroscopicbehavior meets the more exoticproperties of the atomic and molecularworld (e.g. quantum effects)

Behavior is intermediate betweenisolated atoms/molecules and bulkmaterials

Coupling of size with properties is key

Size/PropertiesSize/Properties

Facts About Facts About NanoNano

~800 M in research from federal gov in 03

Political support from both sides of the aisle -NNI

Major universities across the world are investing onnanotech

Across many disciplines Chemists, physicists, biologists, engineers, doctors,

computer scientists

Facts About Facts About NanoNano Nano is big business

1T market by 2015 Fastest-growing industry in history Larger than telecom & IT combined (1998) Private spending on nano 1 B

Priority for IBM NEC HP … Start-ups

Facts About Facts About NanoNano News media

CNN, MSNBC Nobel Prize several times for Nanotech Feynman Prize for Nanotechnology Forbes Cover in 2001

“The Next Big Idea” Episodes in

Star Trek: The Next Generation X-Files

Nanotech CompaniesNanotech Companies

Nanotech VC FundingNanotech VC Funding

Nanotech FundingNanotech Funding

Is It Real?Is It Real?

Faster-burning rocket fuel Automotive parts Tennis balls (2002 Davis Cup) Sunscreen lotions

NanocompositesNanocomposites

• Composites are made from different classesof materials

• Combine best features from both• Typically tradeoffs

– Stiffness– impact

Polymer NanocompositesPolymer Nanocomposites

Spheres(0-D)

Rods(1-D)

Layers(2-D)

Network(3-D)

NanocompositesNanocomposites vs. Composites vs. Composites Inorganics

soft, flexible nanoparticles …as opposed to hard, rigid macrofillers

Synergy effect on crystal phase/morphology of polymer effect on structure/dynamics …as opposed to simple reinforcement

Interfaces behavior dominated by interfaces/synergy …as opposed to weighted average of bulk properties

NanocompositesNanocomposites: Property Profile: Property Profile

Nanocomposites combine: stiffness – toughness stiffness – melt viscosity non-swelling – toughness flame resistance – ability to process low CTE – low modulus ??? low CTE – low viscosity ???

Avoid property tradeoffs Unique opportunities in new materials design

Automotive Applications

www.gm.com

Lightweight

Stiffness/Impact strength

2002 GMC Safari

Chevrolet Astro

540,000 lbs/yr

10 15 20 25 30 35 40

002 !11

1 !020 !

001 "

110 !

200

/ 110

" PVDF

PVDFNC-MMT

PVDFNC-20A

PVDFNC-30B

Inte

nsit

y / a

.u.

2# / deg

XRD and Morphology of PVDF & XRD and Morphology of PVDF & NanocompositesNanocomposites

2µm

1µm

PVDF

PVDF-NC

0 50 100 150 200

0

2x107

4x107

6x107

PVDF

PVDFNC5-20A

PVDFNC5-30B

Str

ess /

Pa

Strain / %

Mechanical Response of PVDF Mechanical Response of PVDF NanocompositesNanocomposites

Mechanical Response of PLG Mechanical Response of PLG NanocompositesNanocomposites

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

0 50 100 150 200

Elongation (%)

Str

ess (

MP

a)

ABPLG

ABPLG/Silica 3%

ABPLG/30B 3%

Barrier ApplicationsBarrier Applications

500 nm500 nm

0.0

0.2

0.4

0.6

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1.0

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Volume Fraction Silicate

Re

lati

ve

Pe

rme

ab

ilit

y

PCL Nanocomposite

PCL Composites

(conventionally filled)

A

B

CNT CNT NanocompositesNanocomposites

Properties of CN Properties of CN NanocompositesNanocomposites

-100-80-60-40-20 0 20 40 60 80 10012010

100

1000

10000(b)

E' (

MP

a )

Temperature (oC)

self-assembly common pure PVP0 5 10 15 20

-12

-9

-6

-3

0

3

log [ !

(S

m-1

)]

CNTs Volume Content (%)

Advantages of Laser ProcessingAdvantages of Laser Processing

direct large amounts of energy to specific locations

localized heating

high heating and cooling rates (109 - 1014 K/sec)

low thermal budget

plastic/flexible substrates

patterning

fast

large scale manufacturing (R2R)

400 600 800 1000 1200

0

20

40

60

80

100

SiO2 loading: 10 wt% glass SiO2 on glass SiO2 on glass laser annealed

Tra

nsm

itta

nce

(%

)

Wavelength (nm)

SiOSiO22 Films Films

300 400 500 600 700 800 900

0

10

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ITO on PET

PET ITO on PET (as-prepared)

Laser annealed at 50mJ/cm2

Laser annealed at 75mJ/cm2

Laser annealed at 100mJ/cm2

Tra

nsm

itta

nce (

%)

Wavelength (nm)

ITO: TransparencyITO: Transparency

0 2 4

0

100

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600

Number of Coatings

Sheet R

esis

tance

( KO

hm

s/�)

laser annealed

0.0

0.2

0.4

0.6

0.8

1.0

Sheet R

esis

tance

(Oh

ms/ �

) before laser annealing

ITO: ConductivityITO: Conductivity

BaTiO3 FilmsBaTiO3 Films

20 40 60

(c)

(b)

(a)

(22

0)

(21

1)

(21

0)

(20

0)

(11

1)

(10

1)(

11

0)

(10

0)

2 theta (deg )

-30 -15 0 15 300.85

0.90

0.95

1.00

0.95

1.00

(b)

Electric field (kV cm-1)

(a)

Ca

pa

cita

nce

(n

orm

.)

Process ModelingProcess Modeling

30 mJ/cm2 70 mJ/cm2

110 mJ/cm2

150 mJ/cm2

190 mJ/cm2