can compete with the large capacities that our silicon-graphite composites have demonstrated," he says. "Manufacturers of electric automobiles, laptop computers, cell phones, power tools, and other hybrid microsystems will likely all benefit from this kind of technology," says Scott Vaupen, a spokesman for Sandia's business development department. Vaupen notes Sandia hope to collaborate with others to further develop the technology for eventual licensing and commercialization. 8.1.1 Carbon Nanotube Batteries Experiments with carbon nanotubes, a new form of carbon discovered about a decade ago, have recently suggested that it should be possible to store more energy in batteries using the tiny tubes than with conventional graphite elec- trodes. The experiments, conducted at the University of North Carolina at Chapel Hill, show carbon nanotubes can contain roughly twice the energy density of graphite. One possibility, researchers say, is longer-lasting batteries. "Scientists and others, including the popular press, have shown a lot of inter- est in carbon nanotubes because of numerous potential applications," says Zhou. "They are very strong tubular structures formed from a single layer of ENERGY TO GO-POWER GENERATION carbon atoms and are only about a billionth of a meter in diameter." Beyond batteries, uses may include constructions of flat-panel displays, telecom devices, fuel cells, high-strength composite materials, and novel molecular electronics. The experiments have demonstrated for the first time that nanotubes work better than conventional materials. "In our experiments, we used both elec- trochemistry and solid state nuclear magnetic resonance measurements, which show similar results," says Zhou. "With graphite, we can store, reversibly, one charged lithium ion for every six carbon atoms in graphite, but we found that with nanotubes, we can store one charged lithium ion for every three carbons, also reversibly." Most rechargeable batteries in portable electronics today are lithium ion batteries, which use