Transcript Computers and Chemistry

Defining Nanotechnology
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NANO
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refers to objects on the nanometer scale (most
say anything less than 100 nm)
TECHNOLOGY
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the current state of our knowledge of how to
combine resources to produce desired
products, to solve problems, fulfill needs, or
satisfy wants (Wikipedia)
Nano-related Events
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1959: Richard Feynman gives his famous paper on nanotechnology
There’s Plenty of Room at the Bottom on December 29th at the annual
meeting of the American Physical Society at the California Institute of
Technology (Caltech).
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1985: Robert Curl, Harold Kroto and Richard Smalley make the
completely unexpected discovery that the element carbon can also
exist in the form of very stable spheres. They termed these new carbon
balls fullerenes or “buckyballs”. Curl, Kroto and Smalley subsequently
win the 1996 Nobel Prize for Chemistry.
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1986: Eric Drexler publishes Engines of Creation : The Coming Era
of Nanotechnology, in which he examines the enormous implications
of nanotechnology for medicine, the economy, and the environment.
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2001: The Clinton administration raises nanoscale science and
technology to the level of a federal initiative, officially referring to it as
the National Nanotechnology Initiative (NNI).
Forms of Carbon (Allotropes)
diamond
~0.70 nm
graphite
“buckyball”
“buckytube”
Growing Nanotubes
Forest of nanotubes
Single-walled
nanotube (SWNT)
Nanoparticles are not new…
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There are many examples of the
use of nanoparticles in history
The Lycurgus Cup (Roman 4th
century AD) derives its unusual
properties from gold/silver
nanoparticles embedded in glass
Carbon nanoparticles (in the form of soot)
have been used to reinforce tires for over
100 years
How Small Can You Get?
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A human hair is about 100
microns (micrometers) wide
One micron is about 0.001
times the thickness of a dime
Current microchip transistors
are about two microns wide
The wires that connect the transistors are less
than a micron wide
If vacuum tubes were used in place of the
transistors on a microchip the chip would be the
size of a city block!
Population Densities
376 million transistors per chip
(Pentium D 940 – “dual core”)
100 billion+? components / wafer
6 billion people / world
The Shrinking Transistor
8
10.00
10
number of transistors
7
10
Pentium II
Pentium®
486™ DX
6
10
1.00
386™
286
5
10
0.10
8086
4
10
3
8080
8008
4004
10
1970
1980
1990
year
2000
0.01
2010
smallest feature size (microns)
Pentium 4
Pentium III
Micromachines (MEMS)
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Current applications
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inertial sensors (e.g., in air bags)
medical devices
memory and mass storage
micro-mirrors for digital projection (DLP)
A “Nano” Guitar!
How Can We See Small Things?
Atomic Force Microscopy
cadmium selenide
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silicon
Refrigerator Magnet Imaging
sample
pull probe strip
probe
pull probe strip
What is the best representation?
(a)
(b)
(c)
Imaging Atoms
Scanning-Tunneling Electron
Microscopy (STEM) image shows
individual platinum atoms (bright
blobs) on an alumina support,
with Pt3 clusters circled.
STEM image of a silicon
crystal in the [112] orientation
reveals pairs of atom
columns in which the
intrapair separation is 0.78 Å.
Manipulating Atoms
A single cobalt atom
Joseph Stroscio; Robert Celotta / NIST
A 40-nanometer-wide NIST logo made with cobalt atoms
on a copper surface. The ripples in the background are
made by electrons, which create a fluid-like layer at the
copper surface. Each atom on the surface acts like a
pebble dropped in a pond.
Nanotechnology Products
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Electronics
 processors
(current production Pentium
D chips use 65 nm technology)
 memory chips and storage devices
 displays based on OLED (organic lightemitting diode) technology are brighter,
use less power, and have a wider
viewing angle than conventional diplays
Nanocrystals
smaller
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“Quantum dots” are 10-20 nm sized
crystals that have unique optical
properties. They absorb ultraviolet light
and re-emit light that depends on their
size (see above figure)
Qdot® nanocrystals are marketed by
InvitrogenTM as very specific fluorescent
stains that can be used to track
activity in live cells
Nanocrystals
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NUCRYST Pharmaceuticals develops and
manufactures medical products that fight
infection and inflammation based on
nanocrystalline silver technology.
Smith & Nephew's Acticoat™
antimicrobial barrier dressings (based on
NUCRYST technology) rapidly kill a broad
spectrum of bacteria in as little as 30
minutes
Gold nanoparticles in
biochemistry and medicine
Nanoparticles and nanofibers
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Stain-repellent Eddie Bauer Nano-CareTM
khakis, uses a process that coats each
fiber of fabric with “nano-whiskers”,
helping the fabric to repel liquids.
Sunscreens are utilizing nanoparticles
that are extremely effective at absorbing
light, especially in the ultra-violet (UV)
range. Due to the particle size, they spread
more easily, cover better
Nanocomposites
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Composite refers to a combination of two
types of materials (fiberglass = plastic
resin + glass fibers).
GM and Toyota use plastic nanocomposite
materials for “step assists” and bumpers.
They are stronger, more scratch resistant
and lighter than older materials.
Wilson has created nanocomposite-based
tennis rackets and golf clubs
Nanotubes
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Many companies are trying to perfect
“field effect displays” that are based on
emission from individual nanotubes
Similar to CRT, but each nanotube serves
as an individual electron gun
Uses less power than LCD or plasma, but
picture similar in quality to CRT
May see FED-TVs on shelves in 2006
Nanocatalysts
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Catalysts enhance the rate of
chemical reactions, making chemical
conversion or manufacturing more
efficient
China's largest coal company (Shenhua
Group) has licensed technology from
Hydrocarbon Technologies that will enable
it to liquify coal and turn it into gas. The
process uses a gel-based nanoscale
catalyst.
Nanofilters
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Argonide Nanomaterials, an Orlando
based manufacturer of nanoparticles and
nanofiltration products, makes a filter that
is capable of filtering the smallest of
particles.
The performance is due to it’s nano size
alumina fiber, which attracts and retains
sub-micron and nanosize particles. This
disposable filter retains 99.9999+% of
viruses at water flow rates several
hundred times greater than virus-rated
ultra porous membranes.