Microchips are like potato chips: More of them come out of the oven broken than whole. And of the chips – micro, not potato – that make it to market, many have built-in weaknesses that eventually cause them to fail.

Most people don’t care. The useful lifespan of an electronic device is only about three years, and it’s hard to consume just one. By the time your cell phone’s processor melts down, you’ve already bought a newer model.

But if you’re planning to send a computer on, say, a 10-year mission into deep space, then you need more staying power. The best option­ used to be to send lots of spare processors and cross your fingers. As your probe flew silently­ through the night, you would dream about chips that could fix themselves.

It’s not crazy. A type of processor called a field programmable gate array really can recover on the fly. Invented in 1984, FPGAs don’t have hardwired patterns of circuits. Instead­, their wiring runs through program­mable intersections called logic blocks. They’re slower than ordinary chips, and until recently their high cost limited their application to rapid prototyping of chip layouts. But advances in fabrication are finally lowering the price.

“There’s little need for fault-tolerant chips in the market,” says Jason Lohn, a computer scientist at the NASA Ames Research Center. “But for space applications, we need much longer lifetimes.” His team is working on systems with two processors that are proprietary variations of FPGAs. If a fault occurs in one, the backup chip takes over, generating a new configuration using an evolutionary algorithm – it tries different approaches until a layout emerges that gets the job done. Researchers at NASA’s Jet Propulsion Laboratory exposed their self-healing chip to 250 kilorads of radiation, enough to kill a person (or give them superpowers). After getting fried, the system started fixing itself, attempting up to 100 configurations per second until it found one that worked.

Ultimately, though, engineers hope that chips will do more than recover from a blast of cosmic radiation. “We want systems that can grow, self-repair, adapt, cope with environmental changes, and give us fault tolerance,” says Andy Tyrell, electronics department chair at the UK’s University of York. Tyrell is working on what he calls immunotronics, a digital immune system, complete­ with antibodies. He has designed an electronic circuit that can distinguish between self and other, just like a human being does – though the machine uses strings of data instead of proteins. The system looks for “diseased” information (data with unexpected characteristics) and, if it finds some, reconfigures itself.

Microprocessors may not come into the world with finesse, but they’re learning to grow old gracefully.

By Sunny Bains

More here.