Washington: A team of engineers at the California Institute of Technology (Caltech) have for the very first time developed self-healing integrated chips.
The team, made up of members of the High-Speed Integrated Circuits laboratory in Caltech`s Division of Engineering and Applied Science, has demonstrated this self-healing capability in tiny power amplifiers.
The amplifiers are so small, in fact, that 76 of the chips-including everything they need to self-heal-could fit on a single penny.
In perhaps the most dramatic of their experiments, the team destroyed various parts of their chips by zapping them multiple times with a high-power laser, and then observed as the chips automatically developed a work-around in less than a second.
"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," Ali Hajimiri, the Thomas G. Myers Professor of Electrical Engineering at Caltech said.
"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," he said.
Until now, even a single fault has often rendered an integrated-circuit chip completely useless.
The Caltech engineers wanted to give integrated-circuit chips a healing ability akin to that of our own immune system-something capable of detecting and quickly responding to any number of possible assaults in order to keep the larger system working optimally.
The power amplifier they devised employs a multitude of robust, on-chip sensors that monitor temperature, current, voltage, and power.
The information from those sensors feeds into a custom-made application-specific integrated-circuit (ASIC) unit on the same chip, a central processor that acts as the "brain" of the system.
The brain analyzes the amplifier`s overall performance and determines if it needs to adjust any of the system`s actuators-the changeable parts of the chip.
Interestingly, the chip`s brain does not operate based on algorithms that know how to respond to every possible scenario.
Instead, it draws conclusions based on the aggregate response of the sensors.
Looking at 20 different chips, the team found that the amplifiers with the self-healing capability consumed about half as much power as those without, and their overall performance was much more predictable and reproducible.
The Caltech team chose to demonstrate this self-healing capability first in a power amplifier for millimeter-wave frequencies.
Such high-frequency integrated chips are at the cutting edge of research and are useful for next-generation communications, imaging, sensing, and radar applications.
By showing that the self-healing capability works well in such an advanced system, the researchers hope to show that the self-healing approach can be extended to virtually any other electronic system.
The research is published in the journal IEEE Transactions on Microwave Theory and Techniques.