US scientists create 'friction-free' material

Led by nanoscientist Ani Sumant of Argonne’s Center for Nanoscale Materials (CNM) and Argonne Distinguished Fellow Ali Erdemir of Argonne’s Energy Systems Division, the Argonne team combined diamond nanoparticles, small patches of graphene, and a diamond-like carbon material to create superlubricity, a highly-desirable property in which friction drops to near zero.

According to Erdemir, as the graphene patches and diamond particles rub up against a large diamond-like carbon surface, the graphene rolls itself around the diamond particle, creating something that looks like a ball bearing on the nanoscopic level.

“The interaction between the graphene and the diamond-like carbon is essential for creating the ‘superlubricity’ effect,” he said in a statement. “The two materials depend on each other.”

By creating the graphene-encapsulated diamond ball bearings, or scrolls, the team found a way to translate the nanoscale superlubricity into a macroscale phenomenon. Because the scrolls change their orientation during the sliding process, enough diamond particles and graphene patches prevent the two surfaces from becoming locked in state. The team used large-scale atomistic computations on the Mira supercomputer at the Argonne Leadership Computing Facility to prove that the effect could be seen not merely at the nanoscale but also at the macroscale.