UNIVERSITY PARK, PA. --- Researchers at Penn State's Applied Research Laboratory (ARL) have developed a faster, cheaper and cleaner method of producing ultrafine metal powders, such as silver used in solder, dental fillings, circuit boards, high-speed photographic film and a host of other applications.

Dr. Jogender Singh, ARL senior research associate and associate professor of materials science and engineering, led development of the process. He was recently honored with an R&D Magazine 100 award which recognizes 100 of the best new discoveries or inventions of the year.

Most recently, Singh says, his group has also shown that the new process can substitute for electroplating in some applications by depositing coatings or patterns on metal surfaces. In addition, he expects, eventually, to be able to use the process to produce carbon nanotubes, the invisible carbon wires recently discovered by others, that have stirred so much interest in the microelectronics industry.

Singh initially developed the new process for silver and nickel. Using a household blender, a laser and inexpensive reaction materials, he showed that he could produce ultrafine silver powder, 100 times finer than any now on the market. The silver powder is purer and more uniform too. In the invisible 1 to 100 nanometer range, the individual particles are smaller than the smallest bacteria or about the size of a small virus.

Singh makes the silver powder by putting silver nitrate, an inexpensive, colorless liquid used in pharmaceuticals, photography, and dyes, in the blender with a reducing agent at room temperature. Next, he whirls the mixture while irradiating it in bursts with the laser. As a laser burst hits the liquid, it creates a tiny "hot spot" where the silver nitrate and reducing agent can react. The result is a t
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Contact: Barbara Hale
bah@psu.edu
814-865-9481
Penn State
31-Oct-1997