Over the winter of 1954, the Regency TR-1 was the iPad of its day. It was the world’s first commercially available transistor radio that fit in a shirt pocket. The TR-1 sold for $49.95, and it didn’t include the “standard” 22.5V non-rechargable battery that cost another $1.50 each. In today’s dollars, its price was relative to that of a new iPad. It was every bit as hip as an iPad, and it came in more colors.
Three years earlier, the classic movie “The Day the Earth Stood Still” won a Golden Globe. In one part of the movie, space alien Mr. Carpenter arranges a demonstration of strength by neutralizing all electricity on Earth (except planes in flight and hospitals) for 30 minutes. The scenes of what happened when the electricity was neutralized were, by design, frightening. In those days, people could have made do without electricity or electronic communication much easier than we could now. Are you making a connection yet?
Back then, few people knew that an electromagnetic pulse or radiation from a solar flare can cause electrical breakdown voltages within the solid-state devices such as transistors to be exceeded to the point that semiconductors and circuit boards fry. A pulse can disable everything electronic that is not EMP hardened, including the Internet, and induce high voltage pulses in copper wires. This is one of those nightmare scenarios where your highest priority instantly becomes where your next meals will come from.
It’s something like what we planned for with Y2K, except we knew to the minute when Y2K was supposed to occur, and we had well-developed strategies and plans to work around it. At the station I was with, one line item in our plan minutia was for salespeople to ride bicycles to collect money from clients.
EMP or the perfect solar flare would be like worst case Y2K to a power higher than I can comprehend, and there won’t be much warning, if any. As a broadcast engineer, I like to have a plan B. When you can’t eliminate a known Achilles heel in every component in the workflow chain, what else can you do other than hope some new technology will eventually eliminate the generally unspoken risk?
Note: Photo permission of Steven Reyer (http://www.mequonsteve.com/regency/).
A 100 year-old solution
A solution appears to be on the horizon, according to at least one team of high-level physicists. That solution is based on vacuum tube technology, except it operates at such a small scale that the space between air atoms simulates a vacuum.
The new device, called a nano vacuum tube, is a cross between vacuum tube technology and modern semiconductor devices, combining the best of both. Edison experimented with vacuum tubes. He discovered and patented the “Edison effect,” which is the thermionic emission of electrons from a hot cathode into a vacuum, but he didn’t know what to do with it. The first diode and triode vacuum tubes began to appear about 100 years ago and started fading away about 50 years ago.
The advantages of transistors overwhelmed the physical limitations of vacuum tubes, except for high power RF applications and niche markets such as high end audio. But, transistors (and all solid state devices) have a couple of issues. One is that electrons move slower in a solid than in a vacuum, which limits operating frequencies and thus computing speeds. Electrons in a vacuum theoretically move at 3 x 1010 cm/s, vs. about 5 x 107 cm/s in semiconductor materials. The other issue is the aforementioned Achilles heel, which allows strong radiation and EMP to damage or destroy the atomic structure of the silicon, rendering it electrically useless.
Nano vacuum tubes don’t actually use a vacuum, which is one of many reasons they will be inexpensive to produce. The separation between the source and drain is 150nM, so the statistical chance of electrons colliding with atoms in that tiny space is virtually negligible. Electron collisions and scattering are normal in semiconductor devices, and would be greatly reduced in such a tiny cavity of air. Fewer collisions make for higher speeds.
The nano vacuum tubes are made by etching a small cavity in phosphorous-doped silicon, surrounded by a source and drain, with the gate atop the cavity. The source emits electrons when a voltage is applied to the source and drain. The gate controls the electron flow.
According to a paper published by the American Institute of Physics in May 2012, a research team built a “gate-insulated vacuum channel transistor” operating at less than 10V. The cut-off frequency of the device was 0.46THz, opening the path to “terahertz technology.” Terahertz technology refers to equipment operating in the electromagnetic spectrum between microwaves and infrared.
The same paper suggested that downscaling product size as manufacturing ramps up may decrease gate and drain voltages to less than 1V. At that point, the nano vacuum tube should become a real product to push computing speeds to the next levels and protect equipment from radiation and EMP. Nano vacuum tubes can be manufactured with the same methods and technology presently used to produce ICs.
For now, the technology is still in the demonstration and experimentation stage. But given the base of production capacity already in place, the nano vacuum tube is closer to a leap in technology than a pie in the sky. Among other things, terahertz technology can be useful for identifying the fingerprints of certain molecules, such as drugs, explosives or other things that may be useful in security applications.
The nano vacuum tube’s natural immunity to pulses and radiation, combined with the implications that such technology can take security to the next level, seem to make it the perfect candidate for fast-track government funding.
I doubt if we’ll see any nano vacuum tube technology on the floor at NAB 2013, but I’ll bet it won’t be much longer than that. What’s not to like and want about blazing fast computing systems and networks containing a built-in solution to a potential problem none of us ever want to face?