) in the U.S., returned to his native China last year and is now the director of the new National Engineering Research Center for Nanotechnology in Shanghai. A key part of China's effort to build a nanotech base that can be on the cutting edge of an emerging industry, the center is focusing on practical applications rather than pure research in nanoelectronics and nanobiotechnology.
Work is going on now to build the center's labs on the outskirts of Shanghai. By the end of next year, Han says, the center will have its own semiconductor fab, with a capacity of 1 million wafers per month. It will also have units for biotech and nanomaterials, complete with chemical vapor disposition to produce carbon nanotubes, single-crystal nanowires, nanofilms, nanocoatings, and nanoparticles.
While a lot of people accuse the Chinese of copycatting inventions made elsewhere, Han says one of his goals is to avoid simply repeating the work that scientists in the U.S. are doing. China must come up with innovative ways to use nanotech to solve the problems unique to an emerging economic giant that still has a large poor population.
"SOMETHING UNIQUE." "The R&D that I'm doing is radically different from what I did in the U.S. because we have different market needs," Han explains. "Most people simply follow the direction of what the U.S. is doing. That cannot put China in the lead position. We have to do something unique for China's needs. I don't think that China should follow the American way."
"In my center," Han adds, "we are more focused on energy saving because energy is a big problem in China." Han and his scientists are working on ways to use nanotech to improve China's oil production. His center is working on a collaboration with a state-run oil field in northeastern Shandong province to make smoke-free diesel from heavy oil, a substance that otherwise is hard to turn into useful fuel.
"What we are trying to do is convert heavy oil into light oil by adding some nano additives that can work as catalysts," Han explains. To do that, he and his colleagues will take nanoparticles of rare earth, a highly reactive material that despite its name is abundant in places like Inner Mongolia, and add them to the heavy oil. The rare earth can then act as catalyst to explosions that can transform the heavy oil into light oil. "We are going to put this technology into production and quickly [get it] into the market," he says.
CLEANER SLURRY. China still gets most of its energy needs from coal, and Han is optimistic that nanotech can make China's coal supply cleaner and more efficient. Some 10% of Chinese power plants use a water-coal mixture, or slurry, that's cheaper than oil and more efficient than coal. The government plans to increase slurry use because China has so much coal and so little oil. But Han says slurry not only creates more dust in the power plant and carbon monoxide in the air than oil but also creates a foul-smelling byproduct, hydrogen sulfur.
That's where nanotech can play a role, he believes. Han wants to use rare-earth nanoparticles as catalysts to separate and remove the hydrogen and sulfur. "We can reduce the deposits so when the power plant burns the coal, you don't get the residue on the wall that you have to clean up often," he says. That will not only reduce maintenance costs but mean cleaner air as well.
Han says his center can help to reduce demand for energy, too. For instance, he's working on a project to improve the efficiency of streetlamps. Fluorescent lights have a component called an electronic ballast that combines the magnetic ballast, starter, and transformer into one energy-efficient unit that's easier to install and maintain.
TOO EXCITED TO SLEEP. "Traditionally, ballasts are used in fluorescent lights in the home and office, but not in high-intensity discharge lamps because the lamps are too hot," he says. In the nano domain, materials are less sensitive to temperature, so if you use nanomaterials in the streetlights, it should be possible to have the energy-saving components, Han says. Now Han's center is working with a company in Sichuan province that had been trying in vain for years to come up with a traditional way to solve the heat problems for high-intensity lamps.
"They worked day and night, for one week," recalls Han. "They called me and said 'hey, these are very exciting results.' They felt so excited, they didn't sleep." The collaboration started in February, he says, and production is now under way.
It's not easy for Han to be in China. As is the case with many such "returnees" who had made lives for themselves in the States before China came calling, his family hasn't returned with him. Han's wife and nine-year-old son remain in California. But professionally, projects like these provide Han with a challenge that he didn't get in the U.S.
"When I worked at NASA, I just stayed in the lab and [worked] on needs of NASA, the Defense Dept., and the Energy Dept. -- not some projects that came out of your real experience," he says. "In China, I really want to solve the problem right away. I build technology today. I hope tomorrow it can be used." By Bruce Einhorn in Hong Kong