Scientists enter brave new world of nanotechnology
experiments is becoming more vital as scientists delve deeper into
the potential of nantechnology, according to a US scientist.
Anthony Fletcher reports.
"We cannot use the way physical systems behave on the large scale to predict what will happen when we go to levels only a few atoms in size," Uzi Landman, professor of physics at the Georgia Institute of Technology told the annual meeting of the American Association for the Advancement of Science (AAAS).
"But we know the rules of physics, and we can use them to create model environments in which we can discover new phenomena through high-level computer-based simulations."
Nanotechnology involves the study and use of materials at an extremely small scale - at sizes of millionths of a millimetre - and exploit the fact that some materials have different properties at this ultra small scale from those at a larger scale. One nanometer is the same as one millionth of a millimetre.
In the future, the science may be used in food production, and to detect how fresh food is. Researchers in the UK were recently awarded a £1.4 million government grant to develop a new generation of micro Rheometers to help characterise and develop liquid based products.
A recent Helmut Kaiser study, entitled "Nanofood," argued that in the future, food will be designed by shaping molecules and atoms. Nanotechnology could also be used to manufacture film that will remain transparent, providing the materials are kept smaller than half a micrometer. Possible applications include beer and soft drink bottles with superior barrier properties.
The Foundation for Scientific and Industrial Research at the Norwegian Institute of Technology (SINTEF) is currently using nanotechnology to create small particles in the film and improve the transportation of some gases through the plastic film to pump out dirty air such as carbon dioxide. It is hoped that the concept could be used to block out harmful gases that shorten the shelf life of food.
SINTEF scientists are looking at whether the film could also provide barrier protection and prevent gases such as oxygen and ethylene from deteriorating food.
Much of this technology will require years of further development before it can be used commercially, but advancements in computer technology could provide a short cut. Computers are constantly becoming more powerful and capable of conducting more detailed explorations, and at the same time, scientists across the globe are increasingly becoming interested in the potential of nanotechnology.
It is the intersection of these two trends, according to Landman, that is allowing scientists to investigate realms that are too small for today's technology to explore experimentally.
Landman and colleagues have also used simulations to explore other phenomena, such as the possibility of producing and maintaining a stable flow of liquid on the nanoscale. Their models predicted that it is possible to produce liquid jets only six nanometers wide.
To date, in collaboration with Landman's theory group, there are teams of engineers building nozzles that can produce jets in the 100 nanometer range. Within one year, said Landman, they expect to produce "nanojets" in the 10 nanometer range.
"The opportunity to make new discoveries in ways that weren't possible before is an incredible gift and it has come about only because we can now simulate environments on the computer that are either not yet possible, too expensive or too dangerous to do in the lab," said Landman.
"We are now at a point in history where the science of the small holds the promise of producing a windfall of scientific discoveries. Computers serve tools for discovery in this exciting adventure."
The US nanomaterial market, which totalled only $125 million in 2000, is expected to reach $1.4 billion in 2008 and exceed $30 billion by 2020, according to Nanomaterials, a study from the Freedonia Group.
