A microscopic sensor that can monitor spaceship water quality and also detect biohazards and even diagnose cancer is part of an extensive portfolio of inventions for which a NASA scientist today will receive an award.
Jun Li, a research scientist at the Center for Nanotechnology, NASA Ames Research Center, located in California's Silicon Valley, will be honored by Nanotech Briefs magazine representatives during a ceremony in Boston. Nanotechnology is the creation of materials, devices and systems through the control of matter on the nanometer scale. A nanometer is one-billionth of a meter.
"We are delighted and proud of this achievement," said Meyya Meyyappan, director of the Center for Nanotechnology at Ames.
Li's carbon-nanotube biosensor may well be used to monitor water quality on NASA's next planned spaceship, the Crew Exploration Vehicle that the space agency plans to fly to the moon, Mars and beyond. Carbon nanotubes are extremely tiny tubes measured in nanometers. Scientists say nanotechnology someday could lead to changes in almost everything from computers and medicine to automobiles and spacecraft.
Li won his prize in the 'Innovator' category, in Nanotech Briefs magazine's first annual awards. The biosensor is an electronic chip - about the size of a stamp -- that can detect multiple pathogens, which include various bacteria and viruses. This chip also can diagnose diseases in patients. Some of Li's inventions may even enable deaf people to hear and blind people to see, according to the scientist.
Another invention developed by Li and his colleagues to improve the cooling of computer chips resulted in a second award in the contest's technology category. This second award will be presented to Nanoconduction Inc., Sunnyvale, Calif. A licensing arrangement with NASA gave Nanoconduction the right to use the invention, which is a composite material made of carbon nanotubes and copper.
"When you run your personal computer, its main computer chip gets very hot," Li noted. "Normally, in your computer you have a heat sink, which is a block of copper with fins and a fan to cool the chip. The computer chip is attached to the heat sink, but the contact is very poor," Li explained. "So we invented a hair-like structure for the intersection of the chip and the heat sink. These tiny, whisker-like hairs made of carbon nanotubes are grown directly on the heat sink surface," Li said. In addition, researchers added copper between the 'whiskers.' The copper fills only the lower portion next to the copper heat sink's surface. The additional copper layer helps anchor the feet of the carbon nanotubes in place and spreads heat laterally, according to Li.
"The carbon whiskers stick out like a brush, and make better contact with the computer chip to improve cooling of the chip," Li explained. The award also recognizes other inventions that he developed with his colleagues at NASA Ames, including a process to 'wire' multiple computer chip layers together using carbon nanotubes instead of copper.
"Using the new process, manufacturers will be able to add more cake-like layers of components to silicon chips to increase computer capability," Li said. Because copper's resistance to electricity flow increases greatly as the metal's dimensions decrease, there is a limit on how small copper conductors can be, as well as how much current they can carry. In contrast, extremely tiny carbon nanotubes can substitute for copper conductors in smaller computer chips. Carbon nanotubes are much more robust than copper wires and can carry much more current.
In addition, Li's developments include implantable electrical-neural devices for potential uses in deep brain stimulation. Stimuli from these devices could help Parkinson's disease patients as well as those suffering from epilepsy. In the future, such implanted devices possibly will be able to read neural signals and input them into a computer or vice versa, according to Li. Implantable computer chips may help restore patients' impaired functions such as hearing and vision, he ventured.
Li has published more than 50 peer-reviewed technical papers and filed more than eight patents. More information about the awards and NASA nanotechnology can be found on the World Wide Web at: