3. 1. INTODUCTION
Nanostructures are all around us but what exactly are they and how are they used?
The Greek word "nano" translates as "little man." In metric measurement it means 1
billionth. Nanostructures are between 1 and 100 nanometers (nm) in dimension,
larger than a molecule but smaller than a microscopic object. To put it into context, a
nanostructure is one hundred thousand times thinner than a human hair .
Nanostructures occur in nature. Scientists are also engineering them at an
incredible pace. The study of nanostructures draws people in from disciplines
including physics, biology and engineering. From medical applications to clean
energy solutions, nanostructures are taking the world of science and technology by
storm.
A single-walled carbon nanotube is about 1/50,000th the width of
a human hair.
4. 2. WHY STUDY NANOSTRUCTURE...
Understanding the nanoworld makes up one of the frontiers
of modern
science. One reason for this is that technology based on
nanostructures
promises to be hugely important economically. Nowhere is
this more evident than in semiconductor industry. Moore’s
law makes the observation
that the number of transistors that can be inexpensively
placed on an integrated circuit doubles approximately every
two years. If the size of IC chips
stay approximately the same, then the linear dimension of the
transistorsmust half every four years. Current transistor
fabrication already runs at
45nm, and Intel claim that they will have 32nm technology in
commercial
devices by 2009. Understanding how electrons behave over
such tiny distant
scales is therefore of very obvious importance to the
electronics, communication and computation industries. One
potentially game-changing future
application that we will discuss in this course is the use of
nanostructures to
perform quantum information processing tasks, and in
particular to build a
quantum computer.
5. Nanostructures and nanomaterials are having real-world
impact elsewhere. For example, the Quantum Hall eff ect, for
which K. von Klitzing
earned the Nobel prize, now serves as a measurement
standard for resistance. Quantum dots are making quite a
name for themselves in many
modern application areas such as Photovoltaic devices, QD
lasers, and as
even as fluorescent tracers in biological and medical settings.
The theory of nanostructures is an intellectually very
rewarding topic.
There are fundamental questions: what is the origin of
resistance? what can
we tell about an structure just by counting the electrons
flowing through it?,
and what role does information play in the nanoworld? Their
pursuit involves a broad range of physical concepts and
theories, from simple confinement eff ects familiar from
introductory quantum mechanics through to the
complex many-body physics of the Kondo and fractional
quantum Hall effects. Furthermore, analogies to atomic and
molecular physics abound, as do
formal similarities between mesoscopic transport and
quantum optics. More
traditional condensed matter and quantum many-body
theory all have the
role to play in understanding, an learning how to control,
nanostructures.
6. 3. 10 Ways nanostructures are changing our
word...
1. Nature's Nanostructures
Marine algae, known as diatoms, contain light-bending nanostructures that convert sunlight into energy needed
for reproduction. Scientists think replicating these structures could help develop biosynthetic devices such as a
light-activated drug delivery system .
Lotus plants have an amazing ability to repel water from their smooth leaves, thanks to hydrophobic wax crystals
about 1 nanometer in size. Water rolls off, taking dirt with it, making the lotus a "self-cleaning" plant. Scientists
are using this concept to engineer more sustainable cleaning sprays. Another goal? The self-cleaning shoe .
The beautiful blue wings of the Morpho Rhetenor butterfly of Brazil are the result of layers of nanostructures.
These nanostructures absorb light and reflect a wavelength creating an "optical interference" and the
resplendent blue we see. Laboratories can use this same process to analyze light . It may also be possible to
replicate the construction of nanostructures in butterflies' wings to create improved "optic effects" in products like
paint and varnish.
2. Power Up with Nano Flakes
Nano flakes sound like something we'd eat but they're not; what they may be is the next generation of clean
energy production. Nano flakes are semi-conducting nanostructures that can absorb the sun's energy more
efficiently and cheaply than current solar panels. The scientists working on this project, which is in the prototype
stage, believe nano flakes will be able to convert up to 30 percent of solar energy into electricity. That's
approximately twice the amount of electricity produced by solar panels .
The jury's still out on whether nano flake solar cells can actually be put in production, but one thing's for sure --
nanotechnology is pushing the envelope when it comes to producing clean energy.
Oscillate Wildly to Make Electricity
Nanoparticles have oscillating electrons that move at the same rate as light. Tiny antennas capture the light and
convert its energy to electricity.
3. Space Travel
Space elevators with cables made from resilient carbon nanotubes (CNT) are one possibility for efficient and
cost effective space travel. In theory, these cables would be used to tether an elevator to the ground, eliminating
the cost and energy use of transporting cargo via ship.
The health of astronauts is a primary concern in space travel. Self-mending spacesuits with two layers of
nanorobots have been proposed by researchers. The first layer would be able to self-mend issues like punctures
to a spacesuit. The second layer would be able to administer medications in emergencies. Spacesuits won't be
the only things that can heal themselves. Lightweight spacecraft made from nanotube composites would allow
for more efficient travel. Instead of rocket fuel, solar sails made from thin layers of nanotubes would reflect light,
7. propelling the space ship. There is the possibility of self-mending space ships repairing structural damage
themselves
What's for dinner?
It's estimated that the nanofood market will go beyond $20 billion in 2010. There are currently no labeling
regulations for such products.
4. Nanorobots
Nanorobots are one of the hottest developments in nanomedicine. In the not-so-distant future these tiny objects
may responsible for curing deadly diseases with minimal side effects. Current research points to nanorobots that
could be used to target and destroy tumors, deliver medicine to specific points in the body or break up blood
clots. How they'll move will depend on the design. Ideas include an internal power source or using the patient's
body to generate power. Sperm are even being considered to send these tiny bots all around the body.
Nanobots aren't the only game in town. Scientist at MIT and Harvard have just engineered particles they're
calling nanoburrs that adhere to artery walls and release medicine.
What's for dinner?
It's estimated that the nanofood market will go beyond $20 billion in 2010. There are currently no labeling
regulations for such products.
5. Nanostructures As Art
Nanostructures offer the ability to engineer technical marvels as well as create stunning pieces of art. Museums
around the world have installations dedicated to this genre. Using scanning electron microscope photography,
artist Christian Orfescu creates abstract landscapes. He calls his work "nanoart" and has been organizing
annual competitions for other artists working with nanostructures.
"Nanoart" is also being used to cross from science to art and back again. At the University of Cambridge,
nanostructure photography reveals "complex amorphous and crystalline material" that in turn may lead to the
creation of a new material. This new object may have future applications to electronic and photonics devices .
6. Nanofood
What is nanofood? Food that uses nanotechnology at any point during its production process is considered
nanofood. There are 600 nanofoods on the market today including a variety of canola oil that can
block cholesterol from entering the bloodstream . Ideas for tomorrow are growing at a rapid rate. They include:
Chocolate milkshakes that taste better and are more nutritious than their non-nano counterparts
Bread containing nanocapsules that disperse omega-3 fatty acids
Interactive food that allows you to choose the taste and color
Smart packaging that prolongs shelf life and minimizes chance of contamination
The arrival of nanofoods hasn't gone unnoticed. Controversy swirls around its relatively seamless integration into
our food supply. Proponents of nanofood see it as a solution to such problems as global hunger and food safety.
Critics hold that safety concerns and environmental impacts have been outpaced by rapid nanofood engineering,
going largely ignored by large corporations and slipping under consumer radar.
What's for dinner?
It's estimated that the nanofood market will go beyond $20 billion in 2010. There are currently no labeling
regulations for such product.
7. Science Fiction and Nanotechnology
8. Nanotechnology has been the fodder for hundreds of story lines over the years. While concepts like tiny robots
that can travel through the human body have become reality, others have remained firmly in the world of fiction.
It's worth taking a look backward to see what's in front of us.
The Borg Collective of the "Star Trek" franchise is nanotechnology evil at its best. The Borg invade planets and
space ships, assimilating humans into their "hives" using nanoprobes. Stripping their victims of "useless
emotions" and other individual characteristics, the Borg attempt to parlay their technical superiority into galactic
dominance.
Kim Exler Dexter's Gray Goo, from his popular book "Engines of Destruction," foretells of a future taken over by
nanorobots gone amok. As they convert organic material into gray goo, things take a turn for the worse.
While the probability of human-gobbling goo or artificial intelligence one day overtaking the world is remote, it's
still fun to think about. That said, real-life nanotechnology raises real questions about safety.
Is AI Better than the Real Thing?
Mathematician Vernor Vinge has been writing since 1993 about the concept of "singularity," which includes the
ability to engineer entities that think faster and have greater intellect than humans.
8. Smarter Living Spaces
One day you might be able to change the shape of everyday objects to suit your needs and tastes. The Living
Kitchen Project by Michaël Harboun is working toward creating spaces that are, for lack of a better word, alive.
Claytronics, the concept behind the Living Kitchen Project, involves nano-sized robots. In theory, these nanobots
could join together to form 3D objects that have digital capabilities. In other words, it's programmable matter
.You would be able to trace any object you need and it would appear on the wall instantaneously. The amazingly
cool factor of Claytonics aside, such technology would reduce clutter and cut down on appliances. Why buy what
you need when you could draw a working one?
9. Fossils, Now Available in Color!
Fossils can tell amazing stories. A team of paleontologists from Yale University found preserved color-producing
nanostructures in fossilized feathers. These feathers, which are more than 40 million years old, were taken from
the Messel Shale fossil pit near Odenwalk, Germany. When looked at under anelectron microscope, the feathers
displayed a bright, iridescent array of colors. The green, blue and copper colors came from a very thin layer of
melanosomes, part of the nanostructures preserved on the surface of the feather.
This discovery of fossilized color-producing nanostructures is the first of its kind. Scientists are hoping to use this
knowledge to reconstruct the colors of the feathered dinosaurs and maybe even the fur colors of long extinct
mammals.
Messel Shale, Where All the Best Fossils Hang Out
The Messel Shale, located near Odenwalk, Germany, contains some of the world's best-preserved fossils dating
back 50 million years
10. Nanotechnology
The birth of nanotechnology is credited to Richard Feynman and his defining talk "There's Room at the Bottom."
Nanotechnology, also known as molecular robotics, is taking center stage in the world of nanostructures. It's
commonly defined as "the manipulation or self-assembly of individual atoms, molecules, or molecular clusters
into structures to create materials and devices with new or vastly different properties.
The largely hypothetical field of nanorobotics holds amazing possibilities for disease management.
Nanotechnologies are also being developed that will allow for more efficient space travel and provide cleaner
energy sources. The possibilities are limited only by our imagination. Yet nanotechnology is not without
controversy.
10. 5. References…
Boysen, Earl. "Understanding Nanotechnology." April 29, 2007. (accessed September 5, 2010) http://www.nanotech-
now.com/columns/?article=054
Center For Food Safety. http://truefoodnow.org/campaigns/genetically-engineered-foods/
Choy, Tat Sang. "What are Nanostructures?" May 1998. (accessed September 4, 2010).
http://www.phys.ufl.edu/~tschoy/nanostructure.html
Fahey, Mike. "The Living Kitchen Project Imagines a Gesture-Based Future." August 13, 2010. (accessed September 7, 2010)
http://www.gizmodo.com.au/2010/08/the-living-kitchen-project-imagines-a-gesture-based-future/
Fedder, Barnaby, J. "Doctors Use Nanotechnology to Improve Healthcare." New York Times. November 1, 2004. (accessed
September 5, 2010) http://www.nytimes.com/2004/11/01/technology/01nano.html
Garber, Kathy. "Nanotechnology Food Coming to a Fridge Near You." December 2006. (accessed September 2010)
http://www.nanowerk.com/spotlight/spotid=1360.php
Gaudin, Sharron. "Scientists Use Nanotech to Prevent Heart Disease." January 19, 2010. (accessed September 7, 2010)
