Low-friction interface between layered materials has potential for wear reduction

It has long been known that layered solid materials, particularly graphite, can act as lubricants. A joint project between Tel Aviv and Tsinghua Universities has now found that the interface between graphite and a two-dimensional material, hexagonal boron nitride, exhibits a property known as superlubricity where friction between two surfaces virtually disappears altogether.

"Superlubricity is a highly intriguing physical phenomenon, a state of practically zero or ultra-low friction between two contacting surfaces," said Prof Oded Hod, who led a team at Tel Aviv University (TAU)’s School of Chemistry. "The practical implications of achieving robust superlubricity in macroscopic dimensions are enormous. The expected energy savings and wear prevention are huge."

The study began with a prediction from theoretical and computational groups at TAU that interfaces between graphene and hexagonal boron nitride would exhibit superlubricity. These groups, working under Prof Hod and Prof Michael Urbakh, collaborated with an experimental group at Tsinghua’s mechanical engineering department who used atomic force microscopes to investigate the behaviour of the interface between the two materials and also used spectroscopy measurements to characterise the crystallinity of the graphite surface.