Stanford Ovshinsky pioneered the field of amorphous (disordered or structureless) materials that can be reversibly changed between amorphous and crystalline phases by an energy source, such as electricity or a laser beam. The phasechange produces a change in conductivity, the amorphous structure representing zero (off) and the ordered structure representing one (on). Because the change is stable, these materials, called ovonics, are suitable for computer processors and memory, optical data storage, high-temperature superconductivity, and silverless photography.
Ovshinsky was born in Akron, Ohio, where he graduated from high school and from trade school as a machinist. His first invention, in the early 1940s, wasan automated lathe that became widely used. In the early 1950s, while workingas research director of an auto parts manufacturing company, he experimentedwith switches that worked like neurons (brain cells). Since the brain does not require ordered structures to use energy and store information, Ovshinskyreasoned that engineered energy-information systems did not need them either.
After experimenting with amorphous materials containing tellurium, arsenic, and other members of the chalcogenides, he discovered that they changed phasewhen a certain voltage threshold was reached. Both heat and electronic conditions are involved in the transformation.
In 1957, he built his first ovonic switch; applications have followed since then. As semiconductors, amorphous materials are very fast and less expensiveto make than the crystals used in conventional semiconductors. Ovonics are being used in direct-overwrite optical data disk storage. This means new data can be written on an optical disk without first deleting the old data.
Ovonic materials are also being studied as superconducting materials. They retain their superconducting properties at much higher temperatures than conventional superconducting materials, which must work near a temperature of absolute zero.
Because of the novelty of his ideas and his lack of academic credentials, Ovshinskys initial paper on ovonics was initially greeted with extreme skepticism by scientists and engineers. However, he persevered because he believed inhis designs and in his ability to make products from them.
Ovshinsky is a fellow of the American Physical Society, an adjunct professorof engineering science at Wayne State University, and an adjunct professor ofphysics at the University of Cincinnati. In 1986, Ovshinsky was awarded theDiesel Gold Medal by the German Association of Inventors. In 1987, public televisions NOVA devoted a one-hour program to his life and work. In 1988, he received the Coors American Ingenuity Award. He was awarded the Toyota Prize in 1991 for having developed the hybrid ovonic nickel-metal-hydride battery. He took first prize for the best article at the International Symposium for Electric Vehicles in 1992. In 1997, a prototype electric vehicle powered by anovonic nickel-metal-hydride batteries traveled 216 miles from Boston to New York City on a single charge at normal highway speeds, thus demonstrating thatelectric vehicles are both practical and capable of providing adequate driving ranges.
Ovshinsky holds over 100 ovonics-related patents and is president of Energy Conversion Devices, located in Troy, Michigan.
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