Plastic electronic devices through line patterning of conducting polymers

A novel method for the preparation of transparent conducting-polymer patterns on flexible substrates is presented. This method, line patterning, employs mostly standard office equipment, such as drawing software, a laser printer, and commercial overhead transparencies, together with a solution or dispersion of a conducting polymer. The preparation of a seven-segment polymer-dispersed liquid-crystal display using electrodes of the conducting polymer poly(3,4-ethylenedioxythiophene) doped with poly(4-styrene sulfonate) (PEDOT/PSS) is described in detail. Furthermore, a method to fabricate an eleven-key push-button array for keypad applications is presented. Properties of the electrode films and patterns are discussed using microscopy images, atomic force microscopy, conductivity measurements, and tests of film stability.