U.S. scientists say they've built self-healing circuits that could lead to chips in your smart phone or computer repairing and defending themselves on the fly. Engineers at the California Institute of Technology said such self-healing chips could recover in microseconds from problems ranging from less-than-ideal battery power to total transistor failure. The researchers have demonstrated the capability by zapping tiny power amplifier circuits multiple times with a high-power laser, observing the chips automatically develop a work-around to bypass the damage in less than a second, a Caltech release reported Monday. "It was incredible the first time the system kicked in and healed itself," electrical engineering Professor Ali Hajimiri said. "It felt like we were witnessing the next step in the evolution of integrated circuits." "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 Caltech engineers said they've given integrated-circuit chips a healing ability akin to that of the human immune system -- something capable of detecting and quickly responding to any number of possible damaging events in order to keep the larger system working optimally. In the circuits, on-chip sensors that monitor temperature, current, voltage and power help a central "brain" on the chip determine if it needs to adjust any of the system's actuators, the changeable parts of the chip, to keep it working. "Bringing this type of electronic immune system to integrated-circuit chips opens up a world of possibilities," Hajimiri said. "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."