Liquid Metal Capsules Used To Make Self-Healing Electronics

MrSeb writes "A crack team of engineers at the University of Illinois has developed an electronic circuit that autonomously self-heals when its metal wires are broken. This self-healing system restores conductivity within 'mere microseconds,' which is apparently fast enough that operation can continue without interruption. The self-healing mechanism is delightfully simple: The engineers place a bunch of 10-micron (0.01mm) microcapsules along the length of a circuit. The microcapsules are full of liquid metal, a gallium-indium alloy, and if the circuit underneath cracks, so do the microcapsules (90% of the time, anyway — the tech isn't perfect yet!). The liquid metal oozes into the circuit board, restoring up to 99% conductivity, and everything continues as normal. This even works with multi-layer printed circuit boards (PCBs), such the motherboard in your computer, too. There's no word on whether this same technology could one day be used by Terminators to self-heal shotgun blasts to the face, but it certainly sounds quite similar. The immediate use-cases are in extreme environments (aerospace), and batteries (which can't be taken apart to fix), but long term we might one day buy motherboards with these self-healing microcapsules built in."

Re:In 1972...

[MrSeb]

Just FYI, my use of 'crack' in the summary is _meant_ to be a pun. I know it sucks to point out jokes... but I wanted to make sure it didn't go unnoticed :P

Re:Delivery mechanism is what?

[Anonymous Coward]

At those scales, the effect of gravity relative to static forces is very small. Very small amounts of liquid metal would spread in any orientation. For those who've soldered, you'll know that solder spreads through wires regardless of which way they're oriented. It takes to the surfaces. Only when you add too much does gravity begin to play a substantial role.

I agree with another poster that whetting is going to be the hardest problem. Although knowing gallium, it's possible that their technique will allow it to alloy with the existing metal and for an amalgam, in essence actually permanently repairing the trace. One would have to experiment to know for sure, but it seems likely that this is the mechanism that is used.

Re:But Doc, we just need a little plutonium!

[DRJlaw]

Only one Slashdot do you need to be told that "metric tons" don't exist - they are tonnes, and require no prefix.

Authorities who disagree with you include:
The Encyclopedia Britannica [britannica.com]
The Cambridge Advanced Learner's Dictionary & Thesaurus [cambridge.org]
The US National Institute of Standards and Technology [nist.gov]
and about 16.5 million other hits on Google.

For some reason, having the homonyms ton/tonne variously refer to a short ton (907.18474 kg), a tonne (1000 kg), or long ton (1,016.0469088 kg a.k.a. English ton) vexes some people. They prefer to specify a "metric ton" rather than so overemphasize "tonne" that they sound as if they have a speech impediment.

The unit of measure exists by virtue of its pervasive use. The fact that you prefer an alternate equivalent does nothing to change that fact.

Re:Let me explain

[DRJlaw]

The SI unit that equals 1000kg is a tonne. But the United States, in a fit of parochialism, has decided to rename it a "metric ton".

The SI unit that equals 1000 Kg is a megagram (Mg, or 10^6 grams). The tonne is not an SI unit [bipm.org], but, in a fit of nostalgia [oxfordwine.co.uk], has been metricized and accepted for use with the SI system.