The invention of paper-thin electrical circuits will facilitate the next generation of high tech products.
By Judy Siegel-Itzkovich
Conventional electrical circuits for radios, TVs, cellular phones, computers and other electronic devices are made from a thin copper plate etched out with acid. But a bright 29-year-old chemist from Birmingham, England has turned the process on its head, designing an electrical circuit on a computer which can then be printed out on chemically treated paper and run through an ordinary printer or photocopier. The patented process, invented by Dr. Andrew Shipway of the Institute of Chemistry at the Hebrew University of Jerusalem, could be used to produce disposable cellular telephones and radios, smart cards, key cards and even T-shirts with blinking lights.
Dr. Shipway says his process is far quicker and less costly than any other electrical circuit-printing methods. The entire process from computer screen to usable circuit can be accomplished in less than 10 minutes - a significant improvement over current techniques. The computer-designed circuit is printed out on special paper impregnated with a palladium metal catalyst. The paper is then placed in a chemical solution, which deposits copper only on the areas not covered by ink, thus creating a paper-thin electrical circuit.
The method can be expanded to produce multi-layer circuits, or applied for use with other metals such as silver. It can also be adapted for printing on plastics, ceramics and fabrics. The process, for which Dr. Shipway recently received the Kaye Prize for Innovations and Inventions, could be used in research institutes, electrical workshops, schools, homes and the commercial sector.
The Kaye Prizes, established by British pharmaceutical industrialist Isaac Kaye and awarded annually since 1994, are aimed at encouraging university faculty and staff to develop innovative methods with good commercial potential, to benefit both the university and the public.
Dr. Shipway came to Israel in 1997 to pursue post-doctoral research. "Before I came, I surfed the Internet to find out what was being done in chemistry in all the universities, and who was doing the research." He made contact with HU Professor Itamar Willner, and from the day he arrived, he went to work in Professor Willner's lab.
"I first thought of the idea of electro-less plating about a year ago; it was just like waking up and saying Eureka!" recalls Dr. Shipway. "In high school, I had built miniature amplifiers and other minute electronic circuits. It was long and tedious work. I came to realize that in nanotechnology (manipulating materials on a molecular scale), traditional working methods become obsolete; it is impossible to operate these tiny things with your hands. Then I thought of building nanoscale circuits from scratch. The concept was based on well-known chemistry principles that date back ten years or more," he explains.
When Dr. Shipway presented the idea to his professor, his response was very enthusiastic. "But I was busy in the lab, and it took a while until I could find spare time to work on it. When I finally tried it, with help from graduate student Gal Sharabi, I succeeded. It was exciting to come up with an idea and then to prove that it works," says Dr. Shipway.
But printing out electrical circuits on paper is not, of course, enough to build a computer or cellular phone, he continues. "You need resistors and capacitators. More steps are needed. However, it is the basis for many exciting applications."