A computer that can truly heal itself would be a revolution in technology. I thought about that this past weekend, when a hard-disk failure brought my work to a halt. My disk diagnostic program tackled the problem and spent an hour trying to fix it without success. The disk was indeed dead, forcing me to spend time installing a new hard disk and operating system. I thought about Hal the computer going nuts in the Kubrick/Clarke movie 2001: A Space Odyssey and had grim thoughts about our reliance on fragile tools.
But help may be on the way. A group at the California Institute of Technology has developed a way for electronic chips to heal themselves. It wouldnt have fixed Hal, but this work demonstrates a principle of self-repair that operates deep inside the complex power amplifier chips the researchers developed. The Caltech team fired lasers into the chips to damage them to varying degrees. Despite all kinds of physical disruption, the chips were able to heal themselves by figuring out how to work efficiently around the problem, no matter where it was.
The key to this kind of self-repair is to build sensors into the chip that can monitor things such as temperature, current and voltage. The chip becomes intelligent enough to isolate the problem and develop a workaround so it keeps working. Remarkably, chips built like this consume about half the power of conventional chips, diagnosing themselves without any human intervention.
Repair, not replace
All of this has important ramifications for the gadgets we use every day. The consumer electronics industry is stuffed with devices that are essentially built to be replaced by newer models before problems occur. If a single transistor fails in your cellphone, it can knock out the entire chip. Almost anything can cause such problems, from changes in temperature to power variations. So we wind up throwing away old equipment that, if it could undergo a repair within the chip, could be saved and upgraded through software rather than replacement.
Of course, repairable chips come into play in a lot of areas besides our cellphones. Imagine all the key areas where a chip failure can cause problems that humans cant immediately correct. Airplanes contain huge numbers of circuits, many of them inaccessible in-flight, which is why earlier work at the University of Illinois should be on your radar. There, a micro-capsule system was recently developed that releases liquid metal whenever a circuit breaks to restore the connection. The system is autonomous, so a failure is momentary and quickly resolved.
Complex systems with human lives on the line that can be made self-healing allow us to push the envelope on research and send crews into the oceans, through the air or into space with far greater reliability.
Products that work better
Autonomy is the word, as we move toward electronic systems that know theres a problem before their operators do. Were not there yet, but this kind of research will lead to mobile devices that, although theyve sustained tiny disruptions within, can route around the problem or heal it on the spot. Your phone keeps working despite the damage and you are none the wiser.
Indestructible circuits are the ultimate goal. When we can achieve them through advances in materials science, everything from car batteries to PCs will work better and longer. My hard-disk replacement was the work of a few hours, but it disrupted my schedule and cost me some money. Ill take self-healing circuits any day to slow the endless upgrade-and-replacement cycle.
Paul A. Gilster is the author of several books on technology. Reach him at firstname.lastname@example.org.