Scientists have created a "stretchy gold" that could one day be embedded in human brains.
The team embedded "networks of spherical nanoparticles" in material reminiscent of elastic to create a stretchy conductor, a University of Michigan press release reported.
The new material has a huge range of possibility, from being used in batteries to human implants that move with the rest of the body.
"Essentially the new nanoparticle materials behave as elastic metals," Nicholas Kotov, the Joseph B. and Florence V. Cejka Professor of Engineering, said. "It's just the start of a new family of materials that can be made from a large variety of nanoparticles for a wide range of applications."
Scientists have spent years trying to come up with a material like the "stretchy gold," and were surprised the solution was to combine the spherical gold nanoparticles with elastics.
"We found that nanoparticles aligned into chain form when stretching. That can make excellent conducting pathways," Yoonseob Kim, first author of the study, said.
The Michigan team watched the innovative material stretch under a microscope.
"As we stretch, [the nanoparticles] rearrange themselves to maintain the conductivity, and this is the reason why we got the amazing combination of stretchability and electrical conductivity," Kotov said.
The most effective version of the material was built with alternating layers, which proved to be more effective than a version which used filtered polyurethane and nanoparticle clumps.
The team hopes the new conducting material will be used as electrodes, with a special emphasis on brain implants.
"They can alleviate a lot of diseases-for instance, severe depression, Alzheimer's disease and Parkinson's disease," Kotov said. "They can also serve as a part of artificial limbs and other prosthetic devices controlled by the brain."
A common problem with implanted electrodes is they build up scar tissue over time, which makes them less effective. A material that could move with the body might eliminate this problem.
"The stretchability is essential during implantation process and long-term operation of the implant when strain on the material can be particularly large," Kotov said.
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