Resources
More information on many of the topics covered is available through the resource links below:
Introduction: A journey to the nano-world
The film 'Powers of 10' was made by Charles and Ray Eames in 1977,
and explores the universe at a range of scales from 10-18 to 1025m.
The Powers of 10 website
(linked here) shows stills from the film for each factor of 10 change
in scale. 
FIFA
dictates that the standard
competition football must be between 68 and 70cm
in circumference (approximately 22cm in diameter). This is sometimes called
a 'Size 5' ball; there is a range of smaller balls for younger players.
Joseph Agro's answer on Mad Science covers the subject of the
smallest
multicellular animal in the world in some detail.
Nature's
Nanotechnologists: Richard Gordon of the
University of Manitoba invented diatom nanotechnology in 1988, when he spoke
to an engineering conference about the way these organisms create
3D nanostructures by controlling deposition of silica in their skeletons.
Bradbury J (2004) Nature's Nanotechnologists:
Unveiling the secrets of Diatoms. PLoS Biol 2(10): e306 DOI: 10.1371/journal.pbio.0020306
Richard Buckminster Fuller (1895-1983) was most famous for his geodesic domes, which included the American Pavilion of Expo 67. Built using a polygonal lattice, geodesic domes are extremely lightweight and stable. Richard was awarded the patent for geodesic domes in 1954. The 'fullerenes', a group of carbon allotropes that includes Buckminsterfullerene, use the same geometrical architectures as Richard's geodesic domes, and were named after him.
You can find out more about the fullerenes - chemistry, physics and
mathematics of spherical carbon molecules - on Wikipedia and on
Bristol University's 'Molecule
of the Month' website.
Above right: an interactive 3D C60 or buckminster fullerene molecule (requires Flash) - rotate the molecule by moving your mouse over it so you can see the pattern of haxagonal and pentagonal carbon atoms
Footnote to A journey to the nano-world
The Royal Swedish Academy of Sciences awarded the 1996 Nobel Prize
for Chemistry jointly to Professor Robert F. Curl, Jr., Rice University,
Houston, USA and Professor Sir Harry W. Kroto FRS for the discovery
of fullerenes. Harry Kroto was a Chemistry graduate of the University
of Sheffield, one of the two partner universities in NanoFolio.
Return to: A journey to the nano-world.
Size is important!
The discovery of Brownian motion is very much a footnote
to Robert Brown's career as a botanist (Wikipedia article),
during which he discovered 2000 species new to the science of the day.
Brownian Motion is one of the very few directly
visible proofs of the atomic nature of the universe. If our 'big world'
wasn't made up of tiny particles (atoms and molecules), then this effect
wouldn't happen. There is a good description of the history and physics of
Brownian Motion on
Wikipedia.
The problem with modelling brownian motion is
that there is a massive disparity in size between the motivating particle and the
object that we can actually see moving. Most models have pretty good physics
for the collision dynamics built in, but the particles are almost equal in
size, and this results in motion which is actually a random walk, and
not Brownian Motion. The important thing about the latter we believe
is that the underlying physics must be inferrred from the observation, not
viewed directly, as under the latter circumstances the physics is 'wrong'...
You are free to make your own decision on this, there are some nice animated
models in the Wikipedia article (linked above). You can see what brownian motion
actually looks like in this video of
Brownian
motion in milk, by Dave Walker. An alternative model is available: Java
Applet* (un-credited), which is similar to the Wikipedia model.
* Please note you may have to download a 'Java Virtual Machine' for
your browser to see the Applet. You can get the machine from Sun Microsystems;
the download will take a few minutes over a broadband connection.
Above is an animation loaded to YouTube by 202Science showing how dividing
cubes up into sub-cubes changes the number of particles, their size and surface area.
With apologies to the original author; it is
not clear who should be credited with the original model on which this
animation is built. Variants on the animation have been uploaded to YouTube a number of
times by different people.
Self-motile nanoparticles is a goal for some advanced
applications, and biokleptic techniques have been most studied. An alternative,
rather neat option, however, is a reaction engine; this has been demonstrated by researchers
at Sheffield in a proof of concept study on
self-motile colloidal particles.
Self-Assembly: Erik Winfree, Nick Papadakis and Paul Rothemund at Caltech have synthesised building blocks with programmed stickiness using DNA molecules. These automatically self-assemble into complex shapes that may presage molecular memories or cellular automata. More recently Damasceno et al. have predicted how the shapes of particles influence how they self assemble.
The
physics of nano-bearings is considered by Richard Jones on his
softmachines weblog from 2006, based on an original paper in Phys. Rev.
(DOI: 10.1103/PhysRevLett.96.186104)
- there is a fair amount of helpful discussion on the blog, if you are
unable to see the original article (subscription required).
Bucky-balls have been used to make wheel analogues for
nano-sized sports cars,
but these only work at elevated temperatures (200°C) - needed
to 'unstick' the wheels form the substrate (a short aricle about the
first nanocar, built in 2005, is available on Wikipedia.
Return to: Size is important!
The nanotechnology timeline
An AFM
image of a phase-separated blend of two conjugated
polymers. Both materials are fluorescent; however, energy transfer
occurs between the polymers to the lowest energy-gap material. Optical
measurements indicate that the fluorescence efficiency of the lower
energy-gap polymer varies strongly across the film surface, and is
greatest in the lower-lying regions. (For more details see
the Electronic
and Photonic Molecular Materials Group website.)
A.J. Cadby, R. Dean, C. Elliott, R.A.L. Jones,
A.M. Fox and D.G. Lidzey, Advanced Materials
19 (2007), 107-111.
The organic optical micropillar was built by a combination of
thermal evaporation, solution-based spin-coating
techniques and focussed ion-beam lithography. By creating such
micropillars containing a single molecule, it may be possible to
produce a single photon light-source for use in quantum cryptography.
(The device was created by the Electronic
and Photonic Molecular Materials Group at the University of Sheffield).
A. Adawi, A. Cadby, L.G. Connolly, W.C. Hung,
R. Dean, A. Tahraoui, A.M. Fox, A.G. Cullis, D. Sanvitto, M.S. Skolnick
and D.G. Lidzey, Advanced Materials 18 (2006), 742-747.
What makes nanotechnology possible?
The earliest 'scanning probe' microscope (SPM) was the Scanning
Tunnelling Microscope (STM), invented in 1981 by Gerd
Binnig and Heinrich Rohrer of IBM's Zurich Lab in Switzerland.
STM works by
scanning a very fine electrical probe over a surface, and measuring the
weak electrical current flowing between the tip and the surface. The technique
can pick out detail as small as 2x10-10m (0.2nm).
Scanning Probe Microscopies allow you to move single atoms around on a surface.
To date this has been with heavy inert atoms and surfaces at low
temperatures, but clearly there is considerable potential in this! The
IBM
Zurich site offers an overview of the techniques used and current
research by the scientists at IBM who invented the technique.
The
atomic force microscope is derived from the earlier STM, and offers
a high resolution in a range of environments. In addition to the contact
mode demonstrated on this site
, the contacting tip can also be vibrated
or twisted as it travels over the surface. This gives information about
the surface energy and friction.
Force distance measurements - e.g. chemical
force microscopy - can
provide information about the chemistry of the surface, while scientists
at Leeds have been using modified AFM techniques to slowly
unravel proteins, and so measure the energy that holds them in shape.
It is the shape of proteins that governs their biological activity, so
this information is central to understanding how they work!
"Mechanically unfolding the small, topologically simple
protein L" by Brockwell, DJ, Beddard, GS, Paci, E, West, DK, Olmsted,
PD, Smith, DA, and Radford, SE; Biophysical Journal 89 (2005) 506-519.
AFM increases drive size: Being able to place single atoms on a surface offers the highest possible data density for any physical two-dimensional system. Reading this data off with a conventional AFM would be very slow, however, so Peter Vettiger et al at IBM have built an imaging device with a compound sensor head consisting of 1024 tips. This prototype has achieved data densities of 100,000Gb per square inch - your iPod manages about 100Gb per square inch.
The piezoelectric effect: When
some crystals are deformed they generate
very high voltages, but the converse is also true - a high voltage applied
to some crystals results in them changing shape. Usually we encounter
piezoelectric devices as gas igniters and similar, where deforming the
crystal generates a spark. A
simple demonstration of piezoelectricity lighting an LED connected across a piezoelectric crystal.
Return to: What makes nanotechnology possible?
Incremental nanotechnology
Richard Jones explains why self-assembly only
works well for soft matter in his article 'Soft
soaping hard matter'.
Superhydrophobic
coatings
can be manufactured in a number of different ways,
as reported by Jessica Gorman in Science News Online.
Science News, 163, March 1 2003, p. 132.
The use of liposomes in cosmetics is covered by Azonano.com
in their A-Z of Nanotechnology. For most purposes, however, liposomes formed from natural
phospholipids are too unstable to be useful, so scientists at Sheffield have been
working on new
synthetic analogues that might one day be useful for smart drug delivery
within the body.
Which company has the most nanotech patents? -
According to some sources the answer is L'Oréal, the French
cosmetics multi-national! We love this factoid so much that we had
to include it; the only question is, is it true?
Wikipedia
(January 2007) reckoned it was (but gave no reference); Norman Wu
said that he'd heard L'Oréal was the biggest nanotech
firm in terms of patents (in Nanotechnology Now, November 2004).
Nanowerk.com
stated that according to the Centre for the
Study of Environmental Change (at Lancaster University) "the
cosmetics industry holds the largest number of patents for nanoparticles"
(a slightly different take). The Centre doesn't confirm this on its
website, however...
Titanium dioxide is the whitest pigment available to artists and decorators (see 'Pigments through the ages' website for a general background). While we don't recommend that you rely on home-made sunscreen, Somerset offer components and some guidelines on their 'Make your own cosmetics' website. We took the optimum particle size for TiO2 in paint from an azom.com article. Note that Somerset is a commercial venture, and the Azom.com article is probably best classed as 'advertising copy' for a particle size analysis system.
Return to: Incremental nanotechnology.
Evolutionary nanotechnology
The basic physics
of Giant Magneto Resistance is covered by the
Stoner Research Group at the University of Leeds. The original hard drive
and many recent advances were commercially developed by IBM, who have
a history
and videos showing how hard drives work. The iPod Nano
actually uses flash memory chips to store data, rather than a magnetic hard drive.
See Inside
the iPod Nano for a full deconstruction of the device.
Inside the iPod Nano by Daniel Turner, MIT Technology
review, December 2005.
The kinds of problems faced by processors with
features less that 100nm wide are reviewed by Wilfried Haensch et al
in Advanced Silicon Technology.
Haensch, W, Nowak, EJ, Dennard, RH, Solomon, PM,
Bryant, A, Dokumaci, OH, Kumar, A, Wang, X, Johnson, JB,
and Fischetti MV IBM journal of research and development, 50 (4/5), 2006.
'Gene chips' or DNA micro-arrays are one of the most powerful
tools in modern proteomics - the study of what cells are actually doing.
Wikipedia
has a nice introduction to the technology of these devices, while
The
Biology Department at Davidson College (North Carolina, USA)
has a pretty exhaustive flash animation showing how gene chip technology
has been used to map the changes in the genes expressed by yeast cells
that are grown in the presence and absence of oxygen.
There
are alternatives to silicon - scientists at a consortium of UK
universities including Sheffield are working with nano-scale devices
built by chemical and physical modification of ordered monolayers.
Nano Lett., 2010, 10 (11), pp 4375–4380
DOI: 10.1021/nl1018782
Publication Date (Web): October 14, 2010
Return to: Evolutionary nanotechnology.
Radical nanotechnology
Micrograph showing fluorescent polymer particles inside dermal fibroblasts (a type of skin cell). In this image the particles show up blue, against a background of the cellular protein F-Actin, which has been stained red. Polymer particles can be made with stimulus responsive shells, or with templated cavities to hold specific molecules. (For more information, see the Polymer and Biomaterials Chemistry Laboratories website.)
Nature is the supreme
nanotechnologist; to get a feel of the diversity of capabilities
inherent in every cell of your body, take a look at the range of molecular
biology video/educational resources available on
Science animations pages,
compiled by Rose Marie Chute.
An example of biomimetic nanotechnology is the creation of a
nano-structured
gel that can act as a synthetic muscle by
researchers from the University of Sheffield, Daresbury Laboratory,
and DUBBLE CRG (France). This material reacts to chemical changes
in its environment by expanding or contracting.
Liz Kalaugher, Nanotech.web 18 January 2006
Turning the world into grey goo was the premise of Michael
Crichton's novel 'Prey' (Harper Collins, 2002), but the scare was
taken up by (amongst others) Prince Charles who feared
"science could kill life on earth".
Scott Rhodie, Scotland on Sunday, Sun 27 Apr 2003
In his book The War of the Worlds
H.G. Wells envisaged the invasion of the earth by Martians. These
super-intelligent beings use giant fighting machines to make short
work of Victorian era defences, but are finally defeated by a
bacterial infection.
We have been re-engineering organisms to make the products we want - such as insulin - for some decades. The Lawrence Berkely National Laboratory (University of California, Berkeley) was the first to establish a 'Synthetic Biology Department' (now a Synthetic Biology Institute), in the new style.
The possibility of radically remodelling living organisms causes some ethical
dilemmas, as documented on the Synthetic Society blog.
The first nano-drug, AbraxaneTM,
received FDA
approval for use in treating breast cancer in 2006. In this drug
formulation the active ingredient 'paclitaxel' is bound into a
nano-scale particle with the protein albumin. Paclitaxel is a potent
drug for cancer treatment, but is not soluble in water, so must be
injected in an oil-based solution. By replacing the oil with a
protein-based carrier particle, it is reported that higher doses
of the drug can be delivered
with fewer side effects.
Possible smart drugs include
dendrimers
- branched macromolecules which have internal cavities to
carry drug payloads, and tuneable surface chemistries.
Possible linkers for MNT include
novel
germanium-based species, being developed by Alan Spivey (Imperial College).
Nano-toxicity: The National
Science Foundation's workshop report
on Emerging issues in nanoparticle aerosol science and technology
(Sheldon K. Friedlander and David Y. H. Pui, 2003) is no longer available online.
Software
Control of Matter is a blog derived from an EPSRC
Ideas Factory on the Software control of matter at the atomic or
molecular scale. This lays down the challenge - "Can we design and
construct a device or scheme that can arrange atoms or molecules according
to an arbitrary, user-defined blueprint?"
Hard nanotechnology is a term
that might be used to describe K. Eric Drexler's potent image of the
possibilities of nanotechnology. In this, simple feedstocks
are converted by molecular mills and atomic level assemblers into complex
devices on your tabletop. There are a number of beautiful simulations of
these imaginary nano devices in action at
lizardfire.com.
K. Eric Drexler, Engines of Creation, Anchor Books 1986
Return to: Radical nanotechnology.
General resources
@Nanofolio is a Twitter feed from the Nanofolio team that picks up recent research and breaking stories in nanotechnology. The feed is updated once or twice a week. There is a digest of the feed on the nanofolio nanotechnology research website.
NANO Magazine an online magazine about all things nano-technological.
The Understanding Nanotechnology website is dedicated to providing clear and concise explanations of nanotechnology applications along with information on companies working in each area.
The 'Soft Machines' blog, written by Prof Richard Jones (University of Sheffield), has been an important resource used in the development of these pages. It provides a digest of the physics of nanotechnology as it happens...
Nanotechnology news and highlights from the Institute of Physics' journal Nanotechnology can be viewed online at: www.nanotechweb.org
NASA's CNT Centre for Nanotechnology has a good gallery of images and videos at www.ipt.arc.nasa.gov/gallery.html
Nanotechnology basics, news and general information are available from www.nanotech-now.com (multimedia page)
Science Daily offers stories from a range of science topics, including this one on nanotechnology. There are usually a couple of breaking stories in nanotechnology every day... A News Feed of science headlines is also available from this site.
The 'What is Nanotechnology?' site was written by Barry Kaye (www.cookandkaye.co.uk), based on materials developed by staff at the universities of Sheffield and Leeds Nanofolio teaching portfolio.
