Investor's Business Daily
Nanotechnology Niche Called 'Quantum Dots' Carries Big Possibilities
Friday October 8, 7:00 pm ET
Doug Tsuruoka
How small can nanotech get?
Picture cancer cells in the human body glowing like Christmas trees. This lets their nuclei and other parts stand out so they can be studied.
The light comes from minute -- just a few mere atoms across -- bits of siliconlike material planted in the cells.
Scientists have dubbed this material "quantum dots," and they are not musings of some distant future. The dots are here now.
Evident Technologies in Troy, N.Y., already makes these dots for more than 400 clients. Its customers range from General Dynamics and Sumitomo Electric to small biotech companies. They use them to indicate wear on complex electronic products and to serve as a valuable indicator light in research of cells and other tiny organisms.
Other companies also are making quantum dots. Researchers are refining and devising more uses for these dots every day.
"Our dots are like tiny snowflakes, a perfectly formed crystal of semiconductor material," said Evident Chief Executive Clint Ballinger. "We can grow them in a bucket or reaction vat and produce them (a ton) at a time. We're talking about trillions of quantum dots that are all exactly the same size."
This uniformity guarantees quality, he says.
The dots are yet another emerging piece of nanotechnology -- the science of making molecule-sized devices and materials. Nanotech is moving from the drawing board to the product-making stage.
NSF Sees Big Dollars
Nanotech is being used to make molecule-sized sensors, car waxes, tennis balls, superstrong materials, even a no-stain coating for pants.
The National Science Foundation predicts global sales of nanotech products will hit $1 trillion -- with a t -- in 10 to 15 years. That's up from just a few hundred million now.
Evident began selling its dots two years ago, says Steven Talbot, the company's marketing chief.
"We produce anywhere from 50 to 100 grams of dots (millions of dots) at a time," Talbot said. "They're used as components of larger products or in research."
Privately held Evident, founded in September 2000, has 30 employees and will surpass $1 million in sales this year, Ballinger says. It's spending more than it's taking in, since research and development costs are high, but Ballinger said his firm is "almost cash flow positive."
The company also faces safety and health issues that affect all makers of nanotech products. Researchers such as the Royal Society in the U.K. are urging studies on the health effects of tiny nanoparticles on the human body.
Evident's dots aren't quite ready for such a cutting-edge use as to be planted in cancer cells. But that's in the works. The dots would tag a tiny cell so scientists with strong microscopes could track a single cancer cell and perhaps solve some of the mysteries of cancer.
Widespread use of the quantum dots remains some years away. But the dots can already be used to tag DNA molecules in medical research. Another use is optical switches for computing and telecommunications.
'Beacons'
In large power switches found at utility plants, the dots can be used as wear indicators. The dots can emit light when power switches or some such product starts to wear down. It's often difficult to keep track of such wear.
"The dots act as beacons," Ballinger said. "When the surface of the switch wears down enough, these quantum dots are released from the material (that covers them) and you can detect their fluorescence."
The dots include cadmium selenide and lead sulfide, so they transmit light like glass rods. That is, they gather available light and emit light where nothing else would.
This also makes them good candidates for use in new light-emitting diodes, or LEDS, Ballinger says. The dots also might be used as detectors for biological and chemical warfare agents.
They could be used to replace dyes that are now used to identify dangerous germs or chemicals.
Another use is mixed in a polymer to make superthin films, again with their light used to indicate various things.
The dots now give off light in one of three colors: red, blue or green. The color depends on the size of the dots. The larger the dot, the longer the wavelength and the redder the color. Dots get bluer as they get smaller and the wavelength shortens.
One problem is that the dots don't emit white light. If they did, they could conceivably be used in such products as computer displays and even light bulbs.
But Evident says it's found a way to make quantum dots that emit white light by using special light-emission controls. The firm hopes to make white-light dots available starting next year, which opens up all kinds of possibilities, says Ballinger.
"It should," he said, "be a very efficient light bulb replacement."
