Researchers Build Victorian-Inspired Computer Switch

Researchers at a US university have produced an electromechanical switch that they say could be the first step towards building computers that could operate at extremely high temperatures, such as the inside of a jet engine, deep below the surface of the earth or on Mercury or Venus.

The technology could also have ecological benefits in that it could reduce computers’ dependence on power-hungry cooling systems, the researchers said.

While the modern computer industrty is based on solid state integrated circuits with no moving parts, the researchers went back to the roots of computing design in the 1830s, when Charles Babbage (below) used mechanical switches to design and build a steam-powered computer known as the “difference engine”. Their research aims to use modern manufacturing techniques to produce mechanical switches small and robust enough to eventually compete with integrated circuits.

Heat resiliency

Te-Hao Lee, Swarup Bhunia and Mehran Mehregany, of Ohio-based Case Western Reserve University, used electron beam lithography and sulphur hexafluoride gas to etch the switches out of silicon carbide, a heat-resilient material, reducing its size to a few hundred nanometres, according to the university.

They configured the switches into an inverter, and found that this continued to operate at temperatures of higher than 500 degrees Celsius, while standard electronic circuits are rendered useless at about 250 degrees Celsius, the team said.

“They work because they’re mechanical and made of silicon carbide, which is robust at high temperatures,” Bhunia said in a statement. “The switches operate in high heat and radiation, at lower voltage and higher density and perform better than transistors designed to operate in high heat.”

Radiation resistance

Because the switches are mechanical they also resist radiation, which could make them suitable for use in space, according to the researchers.

The inverter was able to switch on and off 500,000 times per second, performing a computation each time. That translates to a clock speed of 0.0005 GHz, which the researchers said they hope to improve over time. The switches began to break down after 2 billion cycles, a phenomenon which the researchers said they don’t yet understand.

The team next plans to use its approach to build a memory system that can be combined with the switches to construct a computer.