Will nanotech save the world or is it mostly hype?
By Marsha Walton
The colorful swirls show how cobalt and copper electrons interact with one another.
|WHAT IS NANOTECH?|
Nanotechnology is the science of building machines and materials at the molecular level, where key components are measured in nanometers, or one-billionth of a meter. Nanotechnology applications now being developed range from the fantastic (a supercomputer small enough to fit in your hand) to the mundane (stain-resistant khakis and longer-lasting tennis balls).
GAITHERSBURG, Maryland (CNN) -- Nanotechnology is often mentioned as the tool that will dramatically alter the future.
While its benefits are still years away from reaching the public, scientists hope nanotechnology -- the manipulation of atoms as raw materials -- will eventually live up to the hype it's received for its potential to advance medicine, electronics and manufacturing.
From helping diagnose diseases more accurately to keeping computers running more smoothly, the manipulation of atoms is a challenge with a whole new set of rules. The scientists who work with these tiniest of raw materials see a world just as mesmerizing as those who study the farthest reaches of outer space.
"You would never have thought it possible to pick up an atom and actually move it a few atomic diameters away," said physicist Joseph Stroscio. "It is equivalent to reaching out to the planets and being able to touch a planet and move it from one orbit to another."
Stroscio and Robert Celotta are among physicists at the National Institute of Standards and Technology, or NIST, in Gaithersburg, Maryland, who work on the ground floor of nanotechnology. It's a small, hard-to-imagine world.
A nanometer, one of the measures often used by scientists doing research in the field, is one-billionth of a meter. It takes about 400,000 atoms stacked together to form the width of a human hair.
Nanotech turns some long-held principles of physics upside down. Atoms, and subatomic particles such as electrons and photons, don't always behave according to established science.
"When you go to nano-sized dimensions, matter acts differently," Celotta said.
That can be both a benefit and a problem for fields such as electronics, because circuits and other components may not work the way they do when they are built on a larger scale.
"Seeing" atoms is done with a device called a scanning tunneling microscope. The device was created in the early 1980s by Gerd Binnig and Heinrich Rohrer of the IBM Zurich Research Laboratories. They received a Nobel Prize in physics for its creation in 1986.
"Early on, the scanning tunneling microscope was more used like an archeologist's tool, where you were seeing things for the first time. "It was like Galileo looking up at the stars, but you were looking inward and saying, 'Boy is that neat; I never imagined that would happen,' " Celotta said.
"And now we are getting more like mankind tends to be, rearranging it the way we want it," he added.
The microscope in a lab at NIST's Gaithersburg campus took several years to design and build. Physicists have learned that atoms like things cold and calm.
Inside the microscope, experiments are done at a temperature about minus 455 degrees Fahrenheit. The atoms are guarded from vibration, electricity, magnetic waves and radio waves. There's an ultra-high vacuum inside, so stray oxygen and nitrogen molecules will not interfere with the atomic manipulation. The device is made primarily from the element molybdenum, which can withstand dramatic temperature fluctuations.
Seeing the color of energy
Researchers have observed several unusual properties in this ultra-tiny world.
Physicists Joseph Stroscio, left, and Robert Celotta in the special room that houses the scanning tunneling microscope.
For instance, because of differences in energy, changing the size of a nano-structure changes its color.
"Light has energy, and the color of the light is related to its energy," Stroscio said.
That characteristic could be important for medical researchers looking at nanotechnology for improvements in diagnostics and treatment. In cell studies, but not yet in humans, researchers have used semiconductor nanocrystals as fluorescent markers to detect cancer cells.
"Using nanocrystal probes is an improvement over organic dyes," said Peter Barker, project leader for the NIST- National Cancer Institute Biomarkers Validation Laboratory.
Barker said nanoparticles could provide faster, more reliable and more accurate diagnoses for breast cancer. But medical research, more than any other possible application of nanotechnology, will require safety and ethical oversight. Some elements of these nanoparticles may be toxic, so it's premature to consider human testing.
Noisy atoms found
Physicists studying nanotech made another serendipitous find: They discovered that atoms make noise.
This scanning tunneling microscope is key to nanotechnology research.
Atoms are moved from one location to another with a special type of electric current known as a tunneling current. Monitoring the sound of that manipulation reveals a sort of "cry of protest" from the atom.
"That jumping back and forth, between its preferred place and where we are really forcing it to be, turns out to make this noise," Celotta said.
One of the goals of the NIST researchers is to construct things with thousands of atoms: by giving the microscope a complicated structure to build and letting it complete the job on its own.
Atoms with a mind of their own have conjured up some scary images in science fiction, of nanorobots going out of control. And while nanotechnology, like any new branch of science, requires safeguards and ethical standards, Stroscio is not worried about atoms going astray.
"Nanobots replicating themselves and taking over the world is pretty far fetched," he said.
The goal of the NIST research is to come up with efficient and workable formulas that everyone from manufacturers to physicians can customize for specific products or experiments.
"It is a very precious and unique environment that we can study these quantum phenomenon," Celotta said. "It's a quantum workbench for us."
Georgia Tech physics professor Uzi Landman said he expects it will be five to 10 years before nanoscale "parts" are common in electronic devices; perhaps five to eight years for medical uses.
"It's not that anyone is behind. It's not because anyone is failing," Landman said. "It's just that this is much more mysterious than anyone thought."