Since the Nobel prize-winning discovery of 2D materials in 2004, scientists have believed the crystalline materials consisting of a single layer of atoms intrinsically have ripples that dictate their frictional properties on nanometer-length scales. While such ripples were observed using methods such as electron microscopy, they were never seen during friction experiments, making it hard for scientists to form connections between the presence of ripples and the peculiar frictional properties they exhibit. Now, Baykara and his nanoscience lab at UC Merced, together with collaborators at McGill University in Canada, have for the first time detected the presence of these ripples on the 2D material molybdenum disulfide (MoS2) using atomic force microscopy — the main tool scientists use to study friction on the nanoscale. Their discovery allows concrete connections to be made between the presence of the ripples and the frictional characteristics exhibited by MoS2, especially its direction dependence. MoS2 is a particularly important material used as a “solid lubricant” necessary for nanomachines and for space missions.