Self-healing electronics using carbon nanotube-filled microcapsules

By Darren Quick

21:02 September 17, 2009 PDT

Microcapsules filled with carbon nanotubes could be used to repair electronic circuits (Image: J. Mat. Chem./RSC Publishing)

Dropping an electrical device such as a mobile phone or laptop can prompt a few anxious moments as you rush to see whether your beloved device has survived the fall. Now researchers at the University of Illinois at Urbana-Champaign are working to make such incidents a little less distressing - they're developing a self-healing first-aid kit for electrical systems that could stop circuits failing and lead to safer, longer lasting batteries.

The technology centers around microcapsules filled with carbon nanotubes. In much the same way that tiny liquid-filled capsules rupture to repair a scratch in the self-healing materials we’ve looked at previously, the microcapsules could be placed on failure-prone areas and would rupture to release conductive nanotubes, bridging a break when stress causes a crack in the circuit.

Paul Braun, a professor of materials science and engineering at the University of Illinois who is leading the research project, told Technology Review, “we want to address common failures in cell phones and other portable electronics.” He also predicts that the rate of these failures may increase with the rise of flexible electronics, which are subject to much more mechanical stress.

Self-healing circuits could lead to lighter, cheaper and more efficient devices, particularly in critical, hard-to-repair situations such as satellites or submarines. Currently, engineers build redundancy into such systems to guard against a total failure, but if the devices were able to heal themselves such redundancy systems wouldn’t be necessary.

There is also potential for the technology to be used in batteries to restore the electrical conductivity of damaged battery electrodes, thereby preventing a short circuit that could lead to the battery exploding.

Currently the researchers are working on ways to precisely position the microcapsules using a technique called electrospraying, as well as looking at ways to remove broken microcapsule shells from the electronic device to reduce contamination.

The team’s research appears in the paper Microcapsules containing suspensions of carbon nanotubes, which appears in the Journal of Materials Chemistry.

Posted by: Gabriel Collins