Introduction to Nanotechnology: What, Why and How Introduction to Nanotechnology: What, Why and How...
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Transcript of Introduction to Nanotechnology: What, Why and How Introduction to Nanotechnology: What, Why and How...
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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QuickTime™ and a decompressor
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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!
QuickTime™ and aTIFF (LZW) decompressor
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QuickTime™ and aTIFF (LZW) decompressor
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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