Down the Line: Old Polymer, New Application
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.
According to Brian Balmer, an industry analyst at Frost & Sullivan, organic light-emitting diodes (OLEDs) represent the fastest growth area for the use of conductive polymers. An OLED is a new way to generate light using organic materials rather than the complex crystalline structures found in traditional light-emitting diodes. OLEDs are bright, emissive, colorful devices that offer lower power consumption, wide viewing angle, good contrast and video rate operation.
Balmer says OLEDs are used in flat panel displays for cell phones, personal digital assistants, monitors and televisions. The current global OLED market is $3 million, but Balmer predicts it will skyrocket to more than $700 million by 2005.
"Current advances in display technology will very shortly enable a new generation of flexible and formable ultrathin displays," Balmer points out. He says inexpensive, flexible, paper-thin displays will soon be incorporated into the walls and furniture of homes and offices.