Gadget, heal thyself

In the top image, microcapsules full of liquid metal sit atop a gold circuit. When the circuit is broken (center) the microcapsules rupture, filling in the crack and restoring the circuit's functionality (bottom).

(Credit: Graphic by Scott White/University of Illinois at Urbana-Champaign)

The Geek Squad might not like this development, but we're excited about it. Engineers at the University of Illinois have developed a self-healing system for electronics that they say can restore conductivity to failed circuitry in "mere microseconds."
Today's ever-denser chips face more reliability problems due to the increasingly sophisticated demands on electronic devices. When one circuit within an integrated chip fails, the whole chip, and even the whole device (and your pressing deadline, of course) can go down with it.
"In a multilayer integrated circuit, there's no opening it up," Nancy Sottos, a professor of materials science and engineering at the University of Illinois at Urbana-Champaign, said in a statement. "Normally you just replace the whole chip. It's true for a battery too. You can't pull a battery apart and try to find the source of the failure."

University of Illinois researchers minding the circuit gap are (from left) Nancy Sottos, Scott White, and Jeffrey Moore.

(Credit: L. Brian Stauffer)

To get around the need for external intervention and diagnostics (which may not be readily available for spacecraft or defense-based aircraft, for example), the researchers adapted a previous technique they'd developed for self-healing polymer materials.
They placed tiny microcapsules (as small as 10 microns in diameter) filled with liquid metal on top of a gold line functioning as a circuit. When the circuit cracks, the microcapsules break open, releasing the liquid gallium-indium alloy into the gap and restoring electrical flow--up to 99 percent in most cases. The liquid does its bidding in less time than it takes to blink.
"Rather than having to build in redundancies or to build in a sensory diagnostics system, this material is designed to take care of the problem itself," said chemistry professor Jeffrey Moore, a co-author of the team's research paper, "Autonomic Restoration of Electrical Conductivity," which appears in the latest issue of the journal Advanced Materials.
While we probably shouldn't expect to see self-healing tablets and smartphones by CES 2012 (or even 2013), we are intrigued by the promise such gadgets hold for product reliability and reducing e-waste. For now, the researchers are particularly interested in applying their system to improving batteries' safety and longevity, though it's not yet clear just what sort of longevity we're talking about, or how much these little oozing capsules will add to the cost of electronics.

Originally posted at Crave