Boffins develop nanoscale vacuum tube running at .46 THz

Power hungry but radiation resistant relic could make comeback … in spaaaace

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Researchers from NASA and Korea’s National Nanofab Center have cooked up nanoscale vacuum tubes, potentially bringing some of the earliest electronic devices back into the mainstream of technology.

As detailed in a new paper from Applied Physics Letters, the tiny tubes were manufactured using the same processes applied to silicon semiconductors. An important tweak sees a small cavity etched into silicon, bordered by a source, a gate and a drain. The cavity does not enclose a vacuum, but at 150 nanometres across is so small that electrons flowing through it are unlikely to bump into any other matter.

That setup means electrons can pass unimpeded, instead of having to struggle their way through silicon. Test rigs researchers have created show that data therefore screams along at up to .46 terahertz. The price of this power is power: firing up a device made of the tiny tubes needs 10 volts of juice, compared to one volt for a conventional transistor.

Because the circuits in the devices rely on the gap, they can also work well in nasty spots like space where radiation can knock physical circuits into literal disarray. The researchers are therefore rather keen on nano vacuum tubes as a way to harden computers on spacecraft, which today must pack all sorts of bulky and heavy radiation shielding.

As ever, while the researchers are chuffed with their lab work, no-one is willing to suggest a timeframe in which it will be possible to nip out to an electronics retailer and plonk down some cash for a nano-vacuum gadget. Assuming, of course, retailers still exist when the tiny tubes make it to market. ®

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