Flexible plastic for electronic circuits

15-May-07

By adding a polymer acid to a common plastic, chemists at the University of Texas at Austin have developed a plastic with changeable conductivity which could be used to build future electronic devices. This 'doped' plastic can be manufactured at room temperature and can have conductivity ten times higher than the 'non-doped' one. The flexible sheets of plastics obtained in the lab can be printed with wires and interconnects which could be used to design military camouflage that changes colors, foldable electronic displays and medical sensors. This project has been led by Yueh-Lin (Lynn) Loo, an assistant professor of chemical engineering at the University of Texas at Austin, and the members of her research group. Below is a picture of Loo holding a pliable sheet with printed polyaniline wires and interconnects (Credit: Caroling Lee, University of Texas at Austin By combining polyaniline [also known as PANI,] with a chemical that gives it conductivity, Loo discovered she could increase the plastic's conductivity one- to six-fold based on the version of the chemical added. Chemically altered polyaniline has several advantages over the more commonly used metals, like gold and copper, in devices other than computers. For example, Loo's previous research has demonstrated that "doped" polyaniline can be manufactured in solution at room temperatures and without vacuum chambers. Producing metal-based wires requires special manufacturing conditions in addition to the high cost of the metals. I'm sure you all want to know what was the special ingredient added to polyaniline (PANI) to increase its conductivity. It's a polymer acid named poly (2-acrylamido-2-methyl-1-propanesulfonic acid), or PAAMPSA.