Return of the vacuum tube

Vacuum tubes have been retro for decades. They almost completely disappeared from the electronics scene when consumers exchanged their old cathode ray tube monitors for flat screen TVs. Their replacement – the semiconductor – is generally the cheaper, lighter, more efficient, and easier to manufacture of the two technologies. But vacuum tubes are more robust in high-radiation environments such as outer space. And since electrons travel faster in a vacuum than through a semiconductor, vacuum tubes are an intrinsically better medium for electricity.

An international team of researchers from NASA's Ames Research Center in Moffett Field, Calif., and the National Nanofab Center in Korea have combined the best traits of both technologies by making a tiny version of vacuum tubes that could be incorporated into circuits. Their prototype, a vacuum channel transistor, is just 150 nanometers long and was made using conventional semiconductor fabrication methods. Its small size allows it to operate at fewer than 10 volts, much less than a retro vacuum tube requires; with further work, the device could be made to use about 1 volt, which would make it competitive with modern semiconductor technology.

In a paper accepted to the American Institute of Physics' (AIP) journal Applied Physics Letters, the authors write that such a transistor could be useful for applications in hazardous chemical sensing, noninvasive medical diagnostics, and high-speed telecommunications, as well as in so-called "extreme environment" applications for military and space.


Explore further

Designing diamond circuits for extreme environments

More information: "Vacuum nanoelectronics: back to the future? – gate insulated nanoscale vacuum channel transistor," is accepted to Applied Physics Letters.
Journal information: Applied Physics Letters

Citation: Return of the vacuum tube (2012, May 18) retrieved 18 October 2019 from https://phys.org/news/2012-05-vacuum-tube.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
0 shares

Feedback to editors

User comments

May 19, 2012
Presumably using some sort of cold cathode technology? No cheery orange glow from your computer when you turn it on.
I wonder what is the lifetime of these devices? Old technology vacuum tubes operate for thousands of hours but eventually wear out.

May 19, 2012
Welcome. I can suggest a few solutions.

May 24, 2012
Vacuum tubes have not disappeared they just have different jobs now. Broadcast radio transmitters have huge vacuum tube output stages and the magnetron in your microwave oven is a vacuum tube because solid state devices still can not handle the high voltage and frequencys used.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more