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BALTIMORE, Sept. 27, 2002 — Scientists have long been frustrated in their hunt to find a good way to join together materials like metal and ceramic, but a team of researchers is getting ready to manufacture a nanoengineered product that might solve the problem.
On a recent morning in his Johns Hopkins University office, Timothy Weihs, Reactive NanoTechnologies Inc.’s chief executive, held a flat strip of silver metal the size of a cricket in a pair of needle-nose pliers and touched an edge with the flame of a match. Immediately, it burst into an orange ball of light. The metal tarnished and became misshapen.
The simple demonstration reveals the point of the product: When hit with a spark or other form of heat, the foil — composed of thousands of layers of nickel and aluminum — produces extremely high heat over a small surface area.
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The product will be invaluable to segments of the “joining” industry, which is now dominated by soldering, welding and braising methods that generally apply heat over broad areas to fuse together dissimilar materials, Weihs said. The market also includes the adhesives industry, which does not rely upon high heat to connect materials.
Traditional methods are fine for many applications, Weihs said, but not for joining metal and ceramic, for example. The two materials expand and shrink differently when placed under heat. The differences are enough to make the bonds unstable.
But if the nanofoil is used for heat, the high temperatures go only exactly where they are needed, sparing the surrounding metal and ceramic from the destabilizing heat, said Weihs, who has been researching and developing the foil for more than seven years.
The foil is made in a magnetron sputtering system, a refrigerator-size contraption shaped like a magnifying glass. The machine creates metal vapors, which are then condensed into sheets of metal 250 atoms thick. Reactive NanoTechnologies will make a range of foils, all of them composed of alternating sheets of different metals.
Nanotechnology is key to the product. For the foil to work, it must generate heat faster than it conducts it away. The heat comes from atoms mixing together. Since the atoms in the nanolayers of nickel and aluminum, for example, are in such close proximity, they heat more rapidly. Had the foil not been manufactured on the nanoscale, the distance between atoms would be too great and not enough heat would be generated, Weihs said.
Weihs launched the company in January 2001, but didn’t seek funding until January of this year, when he was one of five companies called to present before a gathering of venture capitalists and angels in Virginia. Toucan Capital Corp. in Bethesda, Md., invested $2 million in the company.
Reactive NanoTechnologies, which to date has done all of its work in Johns Hopkins laboratories, is scheduled to move into a manufacturing center in two months. In four months, Weihs said, it should be producing nanofoils for customers. He said the slice of the market his company will target is between $10 billion and $12 billion. Potential customers include the aerospace and automobile industries, semiconductor manufacturers, the hermetic sealing industry and the military.
For now, the company is working with individual firms to solve unique engineering problems, said Caroline Worrall, Reactive NanoTechnologies’ chief financial and chief operating officer. Those contracts, she said, are between $30,000 and $50,000 apiece. Customers pay Reactive Nanotechnologies to figure out the solution to an engineering problem and do the actual joining of the material. Eventually, she said, the company wants to mass-produce the foil and sell it off the shelf to customers. She said the company should be producing millions of square inches of the foils within five years.
“This approach of having a self-propagating reaction in a thin layer at the point of contact is interesting, and it makes a lot of sense. It’s an intriguing application,” said Christopher Murray, IBM’s manager of nanoscale materials and devices. “It addresses a problem that is very challenging. It’s great to have more technological choices to solve this type of problem and it’s equally exciting that nanoscale engineering” may provide answers.
The ceramic-to-metal bond “is a choke point for a lot of technologies,” said Leon Radomsky, an attorney specializing in nanotechnology at the Washington law firm Foley & Lardner. “From semiconductor testing systems to power generation devices, one of the main failures is this metal-to-ceramic weld or bond. There aren’t too many good ways to do this.”
If the Reactive NanoTechnologies foils work, it would have “a positive impact on a lot of industries,” Radomsky said. “But a lot of people are working in this area, so they will be competing with a lot of other bonding technologies. They will have to show theirs is better or cheaper.”
One competitor could be Ziptronix Inc, a Research Triangle Park, N.C., company that focuses on the ceramic-metal bond in the semiconductor industry, said Jim Walker, a principal analyst for semiconductor manufacturing at Gartner Group. The Ziptronix MEMS method, Walker said, employs a unique polish that forms covalent bonds and therefore does not require the high heat of other joining methods.
Only a handful of people comprise Reactive NanoTechnologies now, but Weihs believes the company will grow fast. “The market we need to hit is a very old, stodgy, non-sexy market — joining,” he said. “But we have a novel nanotechnology for that market.”