Plastic electronics is an offshoot of electronics which focuses on devices made from conductive plastics – otherwise known as organic polymers – rather than silicon.
Manufacturing Plastic Electronics
The "heart" of modern electronics are microchips – circuits and wiring "diagrams" are designed and micro-miniaturized to the point that thousands or even millions of circuits are contained in a one-inch square chip which is "burned" (or etched) onto ultra-thin inorganic materials like refined silicon using very high temperatures.
Plastic electronics, on the other hand, follow a different manufacturing process. The process starts with the manufacture of large sheets of PET (polyethylene terephthalate) plastic – the flexible but tough material used in the production of plastic bottles. Circuits are then printed on these sheets using ink-jet printers or using techniques much like those used to print magazines and newspapers – resulting in a process that is cheap, easy to do and faster to produce.
The plastic circuits will be used as the "active-matrix back panes" for large but flexible electronic displays. In an active-matrix display, every dot on the display is managed by a switching element such as thin film transistors (TFT) and the signals on an array of intersecting row and column electrodes. Prior to plastic electronics, these TFTs have been produced using amorphous silicon deposited on a rigid glass substrate at high temperature through a complex series of production procedures.
It is the collection of switching elements and row-column electrodes which are put together on a substrate to form the active-matrix backpane, which is then combined with different front-plane technologies (e.g., Liquid Crystal Diode or LCD screens) to form the display.
For many electronic readers, the best front plane technology is electronic paper which looks like paper and only uses the unit's power when the image shifts or changes (a property called bi-stability). Sony Reader and the iRex Illiad both use electronic paper for their display screens.
Electronic paper, however, loses its thinness and flexibility when combined with a glass-based silicon backpane. The flexible backpane technology of plastic electronics allows the reader device to become flexible, light, thin and robust enough for a wide range of uses where no paper has gone before and to include large data storage capacities.
The Future of Plastic Electronics
The thin, flexible and robust capabilities of plastic electronics have a wide range of possible applications – from hospital bracelets that are automatically updated with relevant patient info when a medical file is changed, to packaging that will say if it has reached the expiration date and to flat panels that can project individually addressed advertising.
Two European companies – Britain's Plastic Logic and Polymer Vision are today developing flexible, portable text readers – devices that can let you carry your whole library on a sheet of plastic. Polymer Vision plans to market a five-inch screen that can be folded up to the size of a cell phone.
The key to this is the extreme cheapness of the product to manufacture and install – and recycle, as is being done with PET bottles now.