A team of researchers from U of T Engineering and Rice University have reported the first measurements of the ultra-low-friction behaviour of a material known as magnetene. The results point the way toward strategies for designing similar low-friction materials for use in a variety of fields, including tiny, implantable devices.
Magnetene is a 2D material, meaning it is composed of a single layer of atoms. In this respect, it is similar to graphene, a material that has been studied intensively for its unusual properties — including ultra-low friction — since its discovery in 2004.
“Most 2D materials are formed as flat sheets,” says Peter Serles (MIE PhD candidate), who is the lead author of the new paper published today in Science Advances.
“The theory was that these sheets of graphene exhibit low friction behaviour because they are only very weakly bonded, and slide past each other really easily. You can imagine it like fanning out a deck of playing cards: it doesn’t take much effort to spread the deck out because the friction between the cards is really low.”
The team, which includes Professors Tobin Filleter (MIE) and Chandra Veer Singh (MSE), MSE postdoctoral fellow Shwetank Yadav, and several current and graduated students from their lab groups, wanted to test this theory by comparing graphene to other 2D materials.
While graphene is made of carbon, magnetene is made from magnetite, a form of iron oxide, which normally exists as a 3D lattice. The team’s collaborators at Rice University treated 3D magnetite using high-frequency sound waves to carefully separate a layer consisting of only a few sheets of 2D magnetene.