Overview andIntroduction to Nanotechnology:

What, Why and HowMark Tuominen Professor of Physics

STEM Science Saturday, October 2, 2010

NanotechnologyThe biggest science initiative since

the Apollo program

Nanotechnology

Nanotechnology is the understandingand control of matter at dimensions ofroughly 1 to 100 nanometers, whereunique phenomena enable novelapplications.

1 nanometer = 1 billionth of a meter= 1 x 10-9 m

nano.gov

How small are nanostructures?

Single Hair

Width = 0.1 mm

= 100 micrometers

= 100,000 nanometers !

Smaller still

Hair

.

DNA

3 nanometers

6,000 nanometers

100,000nanometers

10 nm objectsmade by guided

self-assembly

Red blood cells(~7-8 µm)

Things NaturalThings Natural Things ManmadeThings Manmade

Fly ash~ 10-20 µm

Head of a pin1-2 mm

Quantum corral of 48 iron atoms on copper surfacepositioned one at a time with an STM tip

Corral diameter 14 nm

Human hair~ 60-120 µm wide

Ant~ 5 mm

Dust mite

200 µm

ATP synthase

~10 nm diameterNanotube electrode

Carbon nanotube~1.3 nm diameter

O O

O

OO

O OO O OO OO

O

S

O

S

O

S

O

S

O

S

O

S

O

S

O

S

PO

O

The Challenge

Fabricate and combinenanoscale buildingblocks to make usefuldevices, e.g., aphotosynthetic reactioncenter with integralsemiconductor storage.

Mic

row

orl

d

0.1 nm

1 nanometer (nm)

0.01 µm10 nm

0.1 µm100 nm

1 micrometer (µm)

0.01 mm10 µm

0.1 mm100 µm

1 millimeter (mm)

1 cm10 mm

10-2 m

10-3 m

10-4 m

10-5 m

10-6 m

10-7 m

10-8 m

10-9 m

10-10 m

Visi

ble

Nan

owor

ld

1,000 nanometers =

Infr

ared

Ultr

avio

let

Mic

row

ave

Soft

x-ra

y

1,000,000 nanometers =

Zone plate x-ray “lens”Outer ring spacing ~35 nm

Office of Basic Energy SciencesOffice of Science, U.S. DOE

Version 05-26-06, pmd

The Scale of Things The Scale of Things –– Nanometers and More Nanometers and More

MicroElectroMechanical(MEMS) devices10 -100 µm wide

Red blood cellsPollen grain

Carbonbuckyball

~1 nmdiameter

Self-assembled,Nature-inspired structureMany 10s of nm

Atoms of siliconspacing 0.078 nm

DNA~2-1/2 nm diameter

Applications of Nanotechnology

10 GB2001

20 GB2002

40 GB2004

80 GB2006

160 GB2007

First, An Example: iPod Data Storage Capacity

Hard driveMagnetic data storage

Uses nanotechnology!

Hard Disk Drives - a home for bits

Hitachi

Magnetic Data StorageA computer hard drive stores your data magnetically

Disk

N S

direction of disk motion

“Write”Head

0 0 1 0 1 0 0 1 1 0 _ _

“Bits” ofinformation

NS

“Read”Head

Signalcurrent

Improving Magnetic Data Storage Technology• The UMass Amherst Center for Hierarchical

Manufacturing is working to improve thistechnology

Granular Media

PerpendicularWrite Head

Soft Magnetic UnderLayer (SUL)

coil

Y. Sonobe, et al., JMMM (2006)

1 bit

• CHM Goal: Make "perfect" mediausing self-assembled nano-templates•!Also, making new designs for storage

Since the 1980's electronics has been a leadingcommercial driver for nanotechnology R&D, but other areas(materials, biotech, energy, and others) are of significantand growing importance.

Some applications of nanotechnology has been around fora very long time already:• Stained glass windows (Venice, Italy) - goldnanoparticles• Photographic film - silver nanoparticles• Tires - carbon black nanoparticles• Catalytic converters - nanoscale coatings of platinumand palladium

Applications of Nanotechnology

Why do we want to makethings at the nanoscale?

• To make better products: smaller, cheaper,faster and more effective. (Electronics, catalysts,water purification, solar cells, coatings, medicaldiagnostics & therapy, and more)

• To study and discover completely new physicalphenomena to science and technology.(Quantum behavior and other effects.)

For a sustainable future!

How to Image Nanoscale Objects

Television Set

eye

electron beam

TV screen

Light !electronsource

prelim.

Scanning Electron Microscope (SEM)

SAMPLE

ElectronBeam

DETECTOR

Scanning probe microscope

Surface

Vibrating Cantilever

PS/PEO

AFM image

µmblock

copolymer

Laser Beam

AFM, STM, MFM, others

"Optical Lever"

To determine amplification factor,use the concept of similar triangles

laser pointer

"Optical Lever"

y1

x1

y2

x2

!

y2x2

=y1x1

!

y2 =x2x1y1

For example, if the laser pointer is 2" long, and the wallis 17' (204") away,

!

y2 =2042

y1 "100y1 Motion amplifiedby 100 times!

.

"Optical Lever" for Profilometry

cantilever

laser

.

"Optical Lever" for Profilometry

cantilever

laserLong light path and ashort cantilever giveslarge amplification

Examples: Nanostructures 10 nm and up

Nanomagnet clusters Plasmonic arrays ofnanodots and nanorings

"0" "1" "2" "3"

Multi-level data storage elements

Transport devices

Nanomagnet arrays

Metallic, semiconducting, magnetic nanostructures

Scanning Tunneling Microscope (STM)Uses the quantum mechanical phenomenon known as "electron tunneling"

Figure:TU WeinSTMGallery

STM Image of Nickel Atoms

IBM

Pushing Atoms Around Using STM

IBM

PART 2:Types of Nanostructuresand How They Are Made

Mark TuominenSTEM Science Saturday, October 2, 2010

"Nanostructures"

Nano-objects Nanostructured Materials

nanoscale outer dimensions

nanoscale internal structure

Nanoscale Devices and SystemsIntegrated nano-objects and materials

"nanoparticle""nanorod"

"nanofilm"

"nanotube"and more

Making Nanostructures:Nanomanufacturing

"Top down" versus "bottom up" methods

•Lithography•Deposition•Etching•Machining

•Chemical•Self-Assembly

Nanofilms

Gold-coated plastic forinsulation purposes

"Low-E" windows: a thinmetal layer on glass:blocks UV and IR light

Nanofilm on plasticNanofilm on glass

A thin film method:Thermal Evaporation

Vaporization or sublimation of aheated material onto a substratein a vacuum chamber

vacuum~10-7 torr

sample

source

film

vacuumpump

QCM

vapor

heating source

Pressure is held low to prevent contamination!

Au, Cr, Al, Ag, Cu, SiO, others

There are many otherthin film manufacturingtechniques

Lithography

IBM - Copper WiringOn a Computer Chip

NANONANO

Using a stencil

Photolithography

substrate

process recipe

spin on resist

resist

expose

mask (reticle)

develop

deposit

apply spin bake

spin coating

exposed unexposed

"scission"

liftoff

etch

narrow line

narrow trench

Imprint Lithography

Mold Template

Polymer or Prepolymer

Substrate

ImprintPressure

Heat or Cure

Release

• Thermal Imprint Lithography

– Emboss pattern into thermoplastic or thermoset with heating

• UV-Assisted Imprint Lithography

– Curing polymer while in contact with hard, transparent mold

Scanning probe-basedlithographies

Nanoimprint lithography

Many approaches for controlling the position ofmaterials on surfaces have been developed in the

last decade.

Microcontact printing

Inkjet printing

Nie, Z et al. Nature Nanotech. 2008. 7, 277.

New Patterning Approaches

SelfAssembly

An Early Nanotechnologist?

Excerpt from Letter of Benjamin Franklin to William Brownrigg (Nov. 7, 1773)

...At length being at Clapham, where there is, on the Common, a largePond ... I fetched out a Cruet of Oil, and dropt a little of it on the Water. Isaw it spread itself with surprising Swiftness upon the Surface ... the Oiltho' not more than a Tea Spoonful ... which spread amazingly, andextended itself gradually till it reached the Lee Side, making all thatQuarter of the Pond, perhaps half an Acre, as smooth as a LookingGlass....

A nanofilm!

"Synthesis and Characterization of NearlyMonodisperse Semiconductor Nanocrystallites,"C. Murray, D. Norris, and M. Bawendi, J. Am.Chem. Soc. 115, 8706 (1993)

"Quantum Dots" by Chemical Synthesis

(reverse-micelle method)

Color is determined by particle size!

a

Interaction with Light

"Artificial atom"

!E = hf

420 THz 750 THz

SELF ASSEMBLY with DIBLOCK COPOLYMERS

Block “A” Block “B”

10% A 30% A 50% A 70% A 90% A

~10 nm

Ordered Phases

PMMA PS

Scale set by molecular size

CORE CONCEPT FOR NANOFABRICATION Deposition

Template

EtchingMask

NanoporousMembrane

Remove polymerblock within cylinders(expose and develop)

Versatile, self-assembling, nanoscale lithographic system

(physical orelectrochemical) nanoporous template

Nanomagnets in a Self-Assembled Polymer Mask

1x1012 magnets/in2

Data Storage......and More

!"#$$%&'()*$+,%!-%.)*/)0)1%"23%

"23%

!4%"#56$78%

!"#$%&$'()$*+,-))$./*0(+1#(2-21)%-*$3-4$#2"25('162(&1(7(2.

Block "A" Block "B"

Major Advances in the Last Decade: PatterningApproaches & Device Integration

Block copolymer lithography:A hierarchical-friendly method

S. Park, et al. Science 2009. 323, 1030.I. Bita, et al. Science. 2008. 321, 939.

Y.S. Jung, et al. Nano Lett. 2010. 10, 1000.K. Galatsis, et al. Adv. Mater. 2010. 22, 769.

More Applications of Nanotechnology

Graphene: A new form of nanoscale carbon

Graphene is a single layer ofgraphite

It has excellent electronicelectronic and mechanicalproperties

Scientist and engineers havebeen studying graphenevigorously since 2004

a graphene flake made by rubbing offa layer from graphite

!9%3):#$%&;$<8% =7*)#,>#?#8,@68A#?7*)%-700#B7*#<78%

graphene on copper

Graphene: Large Scale Manufacturing

Roll-to-roll production of graphene for transparent conductingelectrodes

X. Li, et al. Science 2009. 324, 1312S. Bae, et al. Nature Nanotech. 2010. 5, 574.

Will serve to replace indium tin oxidetransparent conducting electrodes

Solar Cells

Konarka

Benefit: Sun is an unlimited source of electronic energy.

Electric Solar Cellsp-n junction interface

cross-sectional view

n-type silicon

p-type silicon

+

-Sunlight

Voltage “load”

CurrentThe electric power produced isproportional to the area of thesolar cell

- - - -- - - - + + + ++ + + + 0.5 Volt

Nanostructured Solar Cells

+

-

Sunlight

Voltage “load”

CurrentMore interface area - More power!

Nanomedicine:Cancer Therapy

Breast cancer therapy

Perhaps the most important result innanotechology so far: People from diversefields working together to solve important

problems in our society• Physics• Chemistry• Biology• Materials Science• Polymer Science• Electrical Engineering• Chemical Engineering• Mechanical Engineering• Medicine• And others

• Electronics• Materials• Health/Biotech• Chemical• Environmental• Energy• Food• Aerospace• Automotive• Security• Forest products

A Message for Students

Nanotechnology will changepractically every part of our lives. It

is a field for people who want tosolve technological challenges facing

societies across the world