Electronics

Self-healing electronics may result in less expensive, longer-lasting devices

Self-healing electronics may r...
Scientists are creating self-healing electronics, that use liquid metal to instantly restore conductivity to cracked circuits
Scientists are creating self-healing electronics, that use liquid metal to instantly restore conductivity to cracked circuits
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A diagram illustrating how the self-healing circuit works
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A diagram illustrating how the self-healing circuit works
Scientists are creating self-healing electronics, that use liquid metal to instantly restore conductivity to cracked circuits
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Scientists are creating self-healing electronics, that use liquid metal to instantly restore conductivity to cracked circuits

A hard material is impregnated with microcapsules that burst when the material cracks, releasing a stored liquid that hardens on contact with the air, thus repairing the crack ... it's a system that we've recently seen used in a number of applications, including self-healing concrete and polymers. Now, a research team from the University of Illinois is applying it to electronics. They have already created a system that automatically restores conductivity to a cracked circuit in just a fraction of a second.

The scientists started with microcapsules as small as 10 microns in diameter, that were filled with a liquid metal. These were spread along the top of a line of gold, which was serving as an electrical circuit. When a crack formed in the gold, the capsules burst and instantly filled the crack with liquid metal, restoring the circuit within microseconds. Ninety percent of the samples were healed to 99 percent of their original conductivity, even when relatively small numbers of the microcapsules were used.

A diagram illustrating how the self-healing circuit works
A diagram illustrating how the self-healing circuit works

Such a system has several advantages over a traditional circuit, besides the obvious fact that it simply doesn't need to be fixed as often.

For one thing, it can often be very difficult to determine where a fault has occurred in an extensive electrical system, such as the miles of wiring inside an aircraft. With self-healing electronics, the break would be autonomously repaired where it occurred.

It would also be easier and less expensive to build electronics, as redundancies and sensory diagnostic systems wouldn't be nearly as important.

Finally, cracks could be healed on circuits located in areas that couldn't be accessed by hand. Ordinarily, when breaks occur in such places, the entire chip (or even the entire device) is just thrown away. By prolonging the lives of electrical systems, the self-healing technology would cut down on the amount of electronic waste entering the environment.

A paper recently published in the journal Advanced Materials details the University of Illinois research. Previously, scientists from that same institution were developing self-healing electronics that incorporated microcapsules filled with conductive nanotubes.

4 comments
Bill Bennett
most of the failures that I see in ECMS in the automotive world are from crappy solder joints using crap solder with low silver content, this could save my clients alot
Dave Flanagan
If you\'re interested in the science behind the story, we\'ve made the original paper free to read: http://dx.doi.org/10.1002/adma.201102888 . Dave Flanagan, Advanced Materials
windykites
I can think of only one metal that is liquid at room temperature, and that is mercury. Any other suggestions?
Myron J. Poltroonian
This seems applicable to a vast variety of applications; from musical instruments to industrial controllers (such as those used in power plants) to avionics. Obvious question: Is there a way for the \"Self Repair to signal the user that it\'s been activated? Otherwise, I envision a false sense of security being engendered and a laxity of preventative maintenance becoming all too common. Human beings being, well, human, that is.