Printed Electronics
Physics
In addition to "switching", an increase in conductivity can also be accomplished in a field effect transistor (organic FET or OFET), or by irradiation (originally-demonstrated in the 1960's). Strong coupling can also occur between electrons and phonons (mechanical oscillations such as heat vibrations, particles of sound) since both are constrained to travel along the polymer backbone.
Applications of conducting polymers
Electroluminescence (light emission) in organic compounds has been known since the early 1950's, when Bernanose and coworkers first produced electroluminescence in crystalline thin films of acridine orange and quinacrine. In 1960, researchers at Dow Chemical developed AC-driven electroluminescent cells using doped anthracene. In some cases, similar light emission is observed when a voltage is applied to a thin layer of a conductive organic polymer film. The increased conductivity of modern conductive polymers means enough power can be put through the device at low voltages to generate practical amounts of light. This has led to the development of flat panel displays using OLEDs, solar panels and optical amplifiers.
High-power N-channel field-effect transistor