Transcript Document 7118801

Introduction to Nanotechnology:
What, Why and How
Mark Tuominen
Professor of Physics
Science Saturday, Sept. 12, 2009: Part 1
Nanotechnology
The 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 Scale
1 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)
1.276 cm
QuickTime™ and a
d eco mpres sor
are nee ded to s ee this picture.
How small are nanostructures?
Single Hair
Width = 0.1 mm
= 100 micrometers
= 100,000 nanometers !
Smaller still
Hair
.
6,000 nanometers
DNA
QuickTi me™ a nd a
TIFF (LZW) de com press or
are need ed to se e th is p icture.
100,000
nanometers
10 nm objects
made by guided
self-assembly
3 nanometers
Applications of
Nanotechnology
First, An Example: iPod Data Storage Capacity
10 GB
2001
20 GB
2002
40 GB
2004
80 GB
2006
160 GB
2007
Hard drive
Magnetic data storage
Uses nanotechnology!
Magnetic Data Storage
A computer hard drive stores your data magnetically
“Read”
Head
“Write”
Head
Signal
S
N
N
S
0
1
current
Disk
0
0
1
0
0
1
direction of disk motion
1
0
_
_
“Bits” of
information
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 Nanostructures
and How They Are Made
Making Nanostructures:
Nanomanufacturing
"Top down" versus "bottom up" methods
•Lithography
•Deposition
•Etching
•Machining
•Chemical
•Self-Assembly
Nanofilms
Nanofilm on glass
Nanofilm on plastic
Au, Cr, Al, Ag, Cu, SiO, others
QuickTime™ and a
decompressor
Pressure
be
are needed
to see must
this picture.
QuickTime™ and a
decompressor
are needed to see this picture.
held low
to prevent contamination!
Gold-coated plastic for
insulation purposes
"Low-E" windows: a thin
metal layer on glass:
blocks UV and IR light
Nanofilm by Electrodeposition
("electroplating")
I
V
cathode
Working
Electrode
(WE)
CuSO4 dissolved in water
"reduction"
Cu2+ + 2e- –> Cu(0)
anode
Counter
Electrode
(CE)
"oxidation"
Cu(0) –> Cu2+ + 2e-
A thin film method:
Thermal Evaporation
Vaporization or sublimation of a
heated material onto a substrate
in a vacuum chamber
sample QCM
film
vapor
Au, Cr, Al, Ag, Cu, SiO, others
Pressure is held low
to prevent contamination!
There are many other
thin film manufacturing
techniques
vacuum
~10-7 torr
source
heating source
vacuum
pump
Lithography
Nanoscience
Rocks!
Rocks
(Using a stencil or mask)
Photolithography for Deposition
process recipe
spin coating
substrate
apply
spin
bake
spin on resist
resist
expose
mask (reticle)
exposed
unexposed
"scission"
develop
deposit
liftoff
narrow line
Lithography
IBM
Copper
Wiring
On a
Computer
Chip
Patterned
Several
Times
Computer
Microprocessor
"Heart of the computer"
Does the "thinking"
Making Small Smaller
An Example: Electronics-Microprocessors
microscale
nanoscale
macroscale
ibm.com
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!
"Quantum Dots" by
Chemical Synthesis
(reverse-micelle method)
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
"Synthesis and Characterization of Nearly
Monodisperse Semiconductor Nanocrystallites,"
C. Murray, D. Norris, and M. Bawendi, J. Am.
Chem. Soc. 115, 8706 (1993)
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
SELF ASSEMBLY with DIBLOCK COPOLYMERS
Block “B”
PS
Block “A”
PMMA
~10 nm
Scale set by molecular size
Ordered Phases
10% A
30% A
50% A
70% A
90% A
CORE CONCEPT
FOR NANOFABRICATION
Deposition
Template
(physical or
electrochemical)
Etching
Mask
Remove polymer
block within cylinders
(expose and develop)
Nanoporous
Membrane
Versatile, self-assembling, nanoscale lithographic system
Nanomagnets in a Self-Assembled Polymer Mask
nanoporous template
1x1012 magnets/in2
Data Storage...
...and More