Alan Heeger, Alan MacDiarmid and Hideki Shirakawa received the 2000 Nobel Prize in Chemistry for the discovery and development of conductive polymers. They discovered that plastic can be made electrically conductive after certain modifications.
There are three main types of ICP: polyanilene, polythiophene and polypyrrole. For a polymer to conduct electric current, it must consist alternately of single and double bonds between the carbon atoms. It must also be "doped," which means that electrons are removed (through oxidation) or introduced (through reduction). These holes or extra electrons move along a molecule as it becomes electrically conductive.