December 22, 2011
Scientists Create Self-Healing Electronic Chips
Researchers at the University of Illinois at Urbana-Champaign say they are a step closer to developing electronic chips that heal themselves.
The scientists created a circuit that heals itself when cracked by using a liquid metal that restored conductivity.
“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," chemistry professor Jeffrey Moore, a co-author of the paper published in the journal Advanced Materials, said in a press release.
During the research, the team created patterned lines of gold onto glass to form a circuit. They then placed microcapsules about 0.0004 inches wide directly onto the lines, or added laminate into which they embedded larger 0.004 inch microcapsules.
The microcapsules in both cases contained eutectic gallium-indium, which is a metallic material chosen for its high conductivity and low melting point.
The device was sandwiched between another layer of glass and acrylic, and then connected to electricity.
The team then bent the circuit until it cracked causing the monitored voltage to fall to zero.
They said the ruptured microcapsules then healed most of the test circuits by pouring the eutectic gallium-indium within one millisecond, restoring nearly all of the measured voltage.
The researchers monitored the devices for months and said the there was no loss of conductivity during that time.
This new work could help electric car batteries last years longer than they currently do. The scientists also said their technique has the potential to offer more sustainable consumer electronic devices.
They said it could find a use for applications like an air- or spacecraft, in which finding the source of the crack can be difficult.
“In an aircraft, especially a defense-based aircraft, there are miles and miles of conductive wire,” Aerospace engineering professor Scott White, who led the research, said in a press release. “You don´t often know where the break occurs. The autonomous part is nice — it knows where it broke, even if we don´t.”
The researchers now plan to further refine their system and explore other possibilities for using microcapsules to control conductivity.
Image Caption: Self-healing electronics. Microcapsules full of liquid metal sit atop a gold circuit. When the circuit is broken, the microcapsules rupture, filling in the crack and restoring the circuit. Credit: Scott White
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