Introduction to Nanotechnology:What, Why and How

Introduction to Nanotechnology:What, Why and How

Mark Tuominen Professor of Physics

Science Saturday, Sept. 12, 2009: Part 1

NanotechnologyThe biggest science

initiative since the Apollo program

Nanotechnology

Nanotechnology is the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, where unique phenomena enable novel applications.

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

nano.gov

Change in Scale1 nanometer = 1/1,000,000,000 of a meter

(A MAJOR change in scale)Analogy

12,760 km

12,760 km = 1.276 x 104 km= 1,276 x 107 m

1.276 x 107 m / 1 x 109

= 1.276 x 10-2 m

= 1.276 cm (one billionth of the earth's diameter)

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1.276 cm

How small are nanostructures?

Single Hair

Width = 0.1 mm

= 100 micrometers

= 100,000 nanometers !

Smaller still

Hair

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6,000 nanometersDNA

3 nanometers

100,000 nanomete

rs10 nm objectsmade by guidedself-assembly

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!

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

Why do we want to make things at the nanoscale?

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

• To introduce completely new physical phenomena to science and technology. (Quantum behavior and other effects.)

For a sustainable future!

Types of Nanostructuresand How They Are Made

Making Nanostructures: Nanomanufacturing

"Top down" versus "bottom up" methods

•Lithography•Deposition•Etching•Machining

•Chemical•Self-Assembly

Nanofilms

Pressure must be held low to prevent contamination!

Au, Cr, Al, Ag, Cu, SiO, othersQuickTime™ and a

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Gold-coated plastic for insulation purposes

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

Nanofilm on plastic

Nanofilm on glass

Nanofilm by Electrodeposition

VI

Cu2+ + 2e- –> Cu(0)

"reduction"

CuSO4 dissolved in water

Cu(0) –> Cu2+ + 2e-

"oxidation"

anodecathodeWorkingElectrode(WE)

CounterElectrode(CE)

("electroplating")

A thin film method:Thermal Evaporation

Vaporization or sublimation of a heated material onto a substrate in 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

NanoscienceRocks

NanoscienceRocks

NanoscienceRocks!

(Using a stencil or mask)

Photolithography for Deposition

substrate

process recipe

spin on resist

resist

expose

mask (reticle)

develop

deposit

liftoffnarrow line

apply spin bake

spin coating

exposed unexposed

"scission"

Lithography

IBMCopperWiringOn aComputerChip

PatternedSeveral Times

Computer

Microprocessor"Heart of the computer"

Does the "thinking"

Making Small SmallerAn Example: Electronics-Microprocessors

ibm.commacroscale

microscale

nanoscale

Self Assembly

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 large Pond ... I fetched out a Cruet of Oil, and dropt a little of it on the Water. I saw it spread itself with surprising Swiftness upon the Surface ... the Oil tho' not more than a Tea Spoonful ... which spread amazingly, and extended itself gradually till it reached the Lee Side, making all that Quarter of the Pond, perhaps half an Acre, as smooth as a Looking Glass....

A nanofilm!

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

"Quantum Dots" by Chemical Synthesis

(reverse-micelle method)

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