Either it’s yet another sign of the impending zombie apocalypse or the beginnings of a new breakthrough for energy efficient computers and other electronic goods, but it looks like the long-dead vacuum tube may be in for a return from the graveyard of technology. A team of researchers at the University of Pittsburgh has proposed that vacuum tubes could be revived to replace silicon as semiconductors, enabling the design of powerful electronic systems packed into nanoscale spaces.
Vacuum Tubes Then…
Vacuum tubes were, literally, relatively large glass tubes that did the heavy lifting for early computers, TV sets and other electronic goods until semiconductor transistors were invented in 1947.
While the height of technology in their day, the use of glass tubes has an obvious downside in terms of durability and sheer bulk.
Rise of the Transistors…
In our era, silicon-based transistors represent the height of technology. They have steadfastly adhered to Moore’s Law for a generation, shrinking in size every 18 months or so while doubling in performance.
Like the vacuum tube, silicon appears to be reaching its physical limit. Though further advances are conceivable, the expense of achieving them is becoming an additional obstacle.
Vacuum Tubes Now…
As described by Pitt’s lead researcher Hong Koo Kim, electron movement in a silicon chip involves a good deal of colliding and scattering. It can be compared to a car driving through heavy traffic or over bumps, sacrificing speed for efficiency. Here’s his solution:
“The best way to avoid this scattering—or traffic jam—would be to use no medium at all, like vacuum or the air in a nanometer scale space. Think of it as an airplane in the sky creating an unobstructed journey to its destination.”
Traditional vacuum tubes won’t do the trick, partly because of their high energy demand, so Kim and his team gave the old concept a complete design overhaul.
In this new version, electrons are coaxed out of silicon to form a two-dimensional airborne gas, or a sheet of charges, in which electrons can rocket along nanoscale channels without fear of colliding or scattering.
The coaxing can be done with a “negligible” electric charge, much as the mere hint of living flesh can catch the attention of any nearby zombie.
So far, though, the research is in the development stage, so the likelihood of seeing a real zombie may be slightly higher than the likelihood of holding an electron gas smart phone in your hand any time soon.
Follow on Twitter: @TinaMCasey.
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