Electromechanical Switches Could Reduce Future Computers' Cooling Needs 95
Earthquake Retrofit writes "Science Daily is reporting that researchers at Case Western Reserve University have taken the first step to building a computer capable of operating in extreme heat. Te-Hao Lee, Swarup Bhunia and Mehran Mehregany have made electromechanical switches — building blocks of circuits — that can take twice the heat that would render electronic transistors useless. 'The group used electron beam lithography and sulfur hexafluoride gas to etch the switches, just a few hundred nanometers in size, out of silicon carbide. The result is a switch that has no discernable leakage and no loss of power in testing at 500 degrees Celsius. A pair of switches were used to make an inverter, which was able to switch on and off 500,000 times per second, performing computation each cycle. The switches, however, began to break down after 2 billion cycles and in a manner the researchers do not yet fully understand. ... Whether they can reach the point of competing with faster transistors for office and home and even supercomputing, remains to be seen. The researchers point out that with the ability to handle much higher heat, the need for costly and space-consuming cooling systems would be eliminated.'"
Relays are back! (Score:4, Informative)
I tried to tell them that tubes and transistors were just a fad. Relays were good enough for the Z4 and they're good enough for us. These kids and their newfangled gadgets...
Re:Slow processors (Score:3, Informative)
The venerable 6502 was also the heart of the VIC 20. A slightly modified/improved version was used in what was the most ubiquitous personal computer, the Commodore 64. Although running at only 1Mhz, most of its instructions executed in less than 3 clock cycles, making for some pretty efficient and fast ML code.
Re:Impervious to electromagnetic radiation (Score:4, Informative)
How prescient ;-)
No, when they mention radiation in the article it's because these devices are radiation-hard, i.e. they will last a long time in a radioactive environment such as many satellites fly in. Standard silicon CMOS devices on the other hand degrade very quickly because charged particles get trapped in the gate oxide changing the gate threshold, degrading performance, and then eventually killing the device. The silicon crystal itself is more vulnerable to defects from radiation, which increases channel resistance, again degrading performance and killing the device.
The SiC MEMs devices are more robust because SiC is more robust at high temperatures and radiation filled environments, plus as a primarily mechanical system rather than electrical, it will probably be more tolerant to crystal defects.
In a computer this will emit just as much electromagnetic radiation as a silicon chip because the radiation comes from the flow of current being turned on and off. It doesn't matter one bit if you do it with a vacuum tube, BJT, MOSFET, or MEMs device, you will get electromagnetic radiation.
It may be more robust to EMP than a Si-CMOS device, but it will still be vulnerable to contact degradation when an EMP causes breakdown of the air or vacuum dielectric.
The military does love the idea of MEMs switches, more so for radar/comms, but they got burned bad after DARPA and DOD agencies funded 10's of millions, or probably more, in R&D with no useful results. The main problem with MEMs switches has always been reliability, which you will see is also a problem in the MEMs devices being promoted in this article.
Re:Relays are back! (Score:3, Informative)
There are STILL applications where vacuum tubes are better than transistors. Guitar amps and other pieces of audio equipment is a prime example. I wouldn't consider an amp that wasn't tube, nor would most serious guitarists. Many audiophiles also swear by tubes, for dynamic range and warmth. If you want a two way radio system to be able to work during a nuclear blast, only tubes will do, as the EMF will render transistors useless.
I would not be shocked to see some new application for tubes or tube-like technology. Tubes are pretty reliable, can take insane punishment, operate in a variety of environments, have exceptional range, tolerate wide variances in input strength and have a reasonable lifetime, even if shorter than transistors.