US Engineers Test Self-Repairing Chips

A team of engineers from the California Institute of Technology (Caltech) has demonstrated a prototype of an integrated circuit that can automatically diagnose and fix many issues that would have previously resulted in total failure.

The power amplifiers for millimetre-wave frequencies created at the Division of Engineering and Applied Science kept operational after being subjected to severe stress and even shot by lasers.

The new chips are not just more reliable, they also consume up to 50 percent less power. In the future, this technology could be implemented in almost any electronic system including computers, home electronics and mobile devices.

The findings were published in the March issue of IEEE Transactions on Microwave Theory and Techniques.

It’s alive!

Today, even the smallest physical flaw or sudden spike in voltage can render a chip completely useless. Physical “wear and tear” also applies to chips, as they age, and repeated use changes the internal properties of the system.

To make integrated electronic circuits more reliable, the Caltech project funded by the US Defence Advanced Research Projects Agency (DARPA) and the Air Force Research Laboratory worked on self-healing.

The smart component can diagnose almost any problem using a network of on-chip sensors that monitor temperature, voltage, current and power. The information is fed to an Application-Specific Integrated-Circuit (ASIC) that can analyse the readings. If the chip’s performance is impaired, it can develop a work-around in less than a second, by adjusting the actuators.

“It was incredible the first time the system kicked in and healed itself. It felt like we were witnessing the next step in the evolution of integrated circuits,” Professor of Electrical Engineering Ali Hajimiri told Phys.org. “We had literally just blasted half the amplifier and vaporized many of its components, such as transistors, and it was able to recover to nearly its ideal performance.”

The ASIC doesn’t need to store algorithms for every possible fault: it has been programmed to adapt to circumstances and keep hundreds of thousands of transistors in their optimum state, according to the sensor readings.

The technology also produces an additional benefit – according to the team from Caltech, due to self-optimisation, the system can cut the power consumption of a chip in half.

“Bringing this type of electronic immune system to integrated-circuit chips opens up a world of possibilities,” said Hajimiri. “It is truly a shift in the way we view circuits and their ability to operate independently. They can now both diagnose and fix their own problems without any human intervention, moving one step closer to indestructible circuits.”

Last month saw the announcement of another innovative chip – the first ever to implement the “Weightless” white space radio standard, developed by Cambridge company Neul.

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