Copper electrical wiring may soon be facing some stiff competition – or actually, some very stretchy competition. Scientists at Pennsylvania State University and Japan's Shinshu University recently created a "super-stretchable" conductive yarn made from graphene.
The researchers started by chemically exfoliating flakes of graphene from a block of graphite. Those flakes were then mixed with water, and that mixture was concentrated into a slurry using a centrifuge. That slurry was then spread across a plate and allowed to dry, forming into a thin transparent film of graphene oxide.
The film was subsequently peeled off the plate and cut into narrow strips, those strips in turn getting wound together using an automatic fiber scroller.
The resulting yarn can be knotted and stretched without fracturing, and is said to be much stronger than other types of carbon fibers – this quality could be due to the presence of tiny air pockets within it.
Removing oxygen from the material boosts its electrical conductivity, and adding silver nanorods to it in the film-fabricating stage could reportedly boost that conductivity further, to the point of matching that of copper. Its stretchability and lighter weight, however, could make it a better alternative in many applications.
A paper on the research was recently published in the journal ACS Nano.
Source: Penn State