Going against everything they learned in school, the Royal Swedish Academy of Sciences has awarded the 2000 Nobel Prize in Chemistry to three researchers who demonstrated that plastics can conduct electricity.

The chemistry prize has been awarded to Alan Heeger, a physicist at the University of California at Santa Barbara, and two chemists, Alan MacDiarmid of the University of Pennsylvania, Philadelphia and Hideki Shirakawa of the University of Tsukuba, for their roles in the discovery and development of electrically conductive polymers. They will share the Skr9 million prize (US$913,000) equally.

The three winners built on a chance discovery to establish that polymers can be made conductive if alternating single and double bonds link their carbon atoms, and electrons are either removed through oxidation or introduced through reduction. The extra electrons or corresponding 'holes' can then move along the 'doped' molecule, making the conjugated polymer conduct electricity almost as well as a metal.

Some 25 years after the trio's initial discovery, conducting organic polymers - effectively acting as semiconductors - are now being developed for applications ranging from light-emitting diodes in electronic displays to cheap replacements for the silicon chip (see Nature 407, 442–444; 2000).

Shirakawa first stumbled across a new method of making trans-polyacetylene films in the early 1970s - a silvery film appeared when 1,000 times too high a concentration of catalyst was added by mistake. Altering the reaction temperature tweaked the reaction enough to produce nearly pure cis-polyacetylene.

Meanwhile, MacDiarmid and Heeger were also experimenting with a metallic-looking film of the inorganic polymer sulphur nitride. After the three met, they jointly discovered that modifying trans-polyacetylene with iodine, as well as altering the polymer's optical properties, boosted its electrical conductivity by a factor of 10 million. They published the results in a seminal 1977 paper (J. Chem. Soc., Chem. Commun. 579; 1977).

Chemists and physicists have taken the field further since then - discovering that organic polymers can be induced to light up through electroluminescence, for instance. Thin polymer layers emit light when an electrical field excites them, which can easily be turned on and off. These conducting polymers could help create flat television screens or luminous traffic signs (see Nature 399, 408–411; 1999). And interior decorating will never be the same if, as many predict, light-emitting wallpaper is one day unrolled.

"I'm surprised, but I think it is wonderful," Lewis Rothberg, a researcher at the University of Rochester, New York said when Nature broke the news of the trio's success to him. "A lot of things started by the discovery they made are not only of tremendous scientific interest but will also have great technological impact."

⇒ http://www.nobel.se/announcement/2000/cheminfoen.html

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