| abstract |
Very stable, polymer-based electrochemical devices, formed by polymerization of thiophene or a derivative such as 3-methylthiophene which is durable in an aqueous electrolyte over a wide pH range, which respond rapidly to chemical or electrical signals, are disclosed. In one embodiment, the device functions as an extremely sensitive sensor which measures changes in chemical concentration or pH. For example, a poly-3-methylthiophene-based device is sensitive to as little as 8×10 -16 moles of an oxidant which reversibly interacts with the polymer, including gas phase oxidants such as I 2 . In a variation of the polymer-based device, a catalyst such as a noble metal or an enzyme, is dispersed on or within the conducting polymer matrix so that the device is responsive to chemicals such as H 2 and O 2 which the polymer would otherwise respond very slowly to. In a second embodiment, a polymer-based electrochromic device consists of polymer-coated microelectrodes which are individually addressed. Very high resolution is achieved by separating the microelectrodes by distances on the order of 10,000 Angstroms. In still another embodiment, the polymer-based device functions as a capacitor with an energy density as high as 200-300 J/cm 3 which can operate at frequencies as high as 100 Hz. Large polymer-based capacitors are useful for storage of solar energy or as automobile batteries. Microcapacitors may be incorporated into conventional integrated circuit designs. |