Polymer transistors show their soft side.
In its present incarnation, the world of electronics has a hard edge. Made mostly from rigid parts, today's devices -- radios, televisions, telephones, and so on -- rely on components made mainly of metal, silicon, and ceramic to perform their tasks.
What if electronics could shed that hard edge? What if soft polymers and organic materials could offer sufficient electronic control to spawn To launch another program from the current program. The child program is spawned from the parent program.
(operating system) spawn - To create a child process in a multitasking operating system. E.g. a new generation of lightweight, flexible machines that could bend to human needs in ways that current products cannot?
Pursuing this vision, Francis Garnier Marie Joseph François (Francis) Garnier (25 July 1835 - 21 December 1873) was a French officer and explorer known for his exploration of the Mekong River in Southeast Asia.
He was born at St. Etienne. , a materials scientist at the Laboratoire des Materiaux Moleculaires in Thiais, France, and his colleagues tell of their efforts to make flexible plastic electronic circuits.
Reporting in the Sept. 16 Science, they describe a method for making field-effect transistors field-effect transistor: see transistor. entirely from organic polymers, using what they call "printing techniques."
"These are very simple, low-energy manufacturing methods compared to what people usually use to make amorphous Unorganized or vague. A lack of structure. For example, the amorphous state of a spot on a rewritable optical disc means that the laser beam will not be reflected from it, which is in contrast to a crystalline state which will reflect light. See crystalline. , silicon-based devices," Garnier says. "Think of printing large circuits continuously on a roller, like a magazine."
Ordinarily, producing a computer chip requires powerful vacuums and high temperatures to deposit metallic materials on a silicon substrate. Such processes are cumbersome, energy-draining, and prone to error. Impurities often cause manufacturers to reject large numbers of chips. The new printing technique bypasses many of these difficulties, Garnier says.
Though researchers have managed to make electrically conductive polymers A conductive polymer is an organic polymer semiconductor, or an organic semiconductor. Roughly, there are two classes-- the Charge transfer complexes and the conductive polyacetylenes. in the past, both as electroluminescent See electroluminescence and EL display. diodes and as other forms of transistors (SN: 3/30/91, p.207; 10/16/93, p.246), they have been unable until now to rid the devices completely of metal attachments.
"This has been a problem,"' says Garnier, "because the polymers are flexible. So when they bend, the rigid connections tend to break."
The new method does away with metallic electrodes Electrodes
Tiny wires in adhesive pads that are applied to the body for ECG measurement.
Mentioned in: Electrocardiography entirely, the group reports. As a result, the transistors not only show reliable electrical characteristics, such as low resistance and high current output, but also "are insensitive to mechanical treatments such as bending and twisting."
In a series of tests, the scientists rolled, twisted, and bent the devices as much as 90[degrees] Yet they kept on working. By contrast, other rigid devices, including various organic transistors with metallic connections, stopped functioning when bent that much.
From such organic polymer electronics, Garnier envisions "pocket-sized |smart' cards with plastic logic circuits." He also sees "car and airplane windshields that can display information," as well as "a large flat panel display A thin display screen for computer and TV usage. The first flat panels appeared on laptop computers in the mid-1980s, and the LCD technology became the standard. Stand-alone LCD screens became available for desktop computers in the mid-1990s and exceeded sales of CRTs for the first time , like a television, that you could roll up."
"Even 5 years ago, people in the field said that to make good transistors only from plastics was totally unrealistic," he adds. "Now here it is."