"We're seeing exports go up by double digits each year ... which translates into jobs back here," said Dan Onorato, Chief Executive of Allegheny County. He will be traveling to China with a delegation in mid-April.

Peter Morici, a professor at the University of Maryland's Robert H. Smith School of Business, said demand for sophisticated U.S.-made products had grown because "the Chinese can't make those products for themselves yet, and you can't readily transfer production over there."

China's advantageous currency exchange rate, which keeps its exports cheap and has long been a point of diplomatic contention, has not affected high-tech products as much as it has goods made with low-cost labor, he said.

"The real problem on the export stuff is that they're not letting stuff in," Morici said. "It's hard to sell cars there. ... They want you to build them there."

Companies that can export to China will benefit, but "there is a real danger we will export a good deal of our industrial know-how and have nothing left to sell," Morici said.

The United States has filed complaints against China at the World Trade Organization over copyright policy after U.S. Trade Representative Susan Schwab said American companies were losing billions of dollars annually from piracy levels in China that "remain unacceptably high."

For some companies, it may be better to avoid putting such intellectual property rights at risk by doing business with China, said Dennis Unkovic, a lawyer who works with companies that export products to China.

"Before, it was a manufacturing job-shop for the world," he said. Now, "they're buying more of the kinds of products they wouldn't have bought five or 10 years ago," such as medical technology devices.

At the Advanced Materials laboratory, the chief executive officer, Sankar, said part of his small firm's cachet is that it sells more than scientific instruments ¡ª it offers his 30 years of experience and the support of his staff.

"I don't think we can move this operation to China or any other country at this point," he said. "It wouldn't make sense."