Scientists have taken inspiration from one of the oldest natural materials to exploit the extraordinary qualities of graphene, a material set to revolutionise fields from computers and batteries to composite materials.
Previous research had focused mainly on the intrinsic properties and applications of the individual sheets. A team has been tackling the challenge of engineering the sheets into macroscopically-useable 3D structures.
"When the atomic graphene sheets are assembled together to form 3D structures, they normally end up with porous monoliths that are brittle and perform poorly," the researcher said."It was generally thought to be highly unlikely that graphene could be engineered into a form that was elastic, which means it recovers well from stress or pressure."
The researchers used cork, which is lightweight yet strong, as a model to overcome this challenge.
"The fibres in cork cell walls are closely packed to maximise strength and individual cells connect in a honeycomb structure which makes the material very elastic," a researcher said.
Using a method called freeze casting, the researchers were able to form chemically modified graphene into a 3D structure that mimicked cork. The graphene blocks produced were lighter than air, able to support over 50,000 times their own weight, good conductors of electricity and highly elastic - able to recover from over 80 per cent deformation.
"We've been able to effectively preserve the extraordinary qualities of graphene in an elastic 3D form, which paves the way for investigations of new uses of graphene - from aerospace to tissue engineering," the researcher said.
"Mimicking the structure of cork has made possible what was thought to be impossible."
This story is reprinted from material from Monash University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.