Observation of the early stages of environmental contamination in graphene by friction force.

Exposure to ambient air contaminates the surface of graphene sheets. Contamination may arise from different sources, and its nature alters the frictional behavior of the material. These changes in friction enable the observation of the early stages of contaminants' adsorption in graphene.

Investigation of the morphological and fractal behavior at nanoscale of patterning lines by scratching in an atomic force microscope.

In this work, the topographical effect of the scratching trajectory and the feed direction on the formation of lithographed lines on the (001) InP surface was investigated using an atomic force microscope (AFM) tip-based nanomachining approach. Nanoscratching tests were carried out using the sharp face of a diamond AFM tip in contact mode. From the topographic maps obtained by AFM, several morphological and fractal parameters were obtained and analyzed.

Giant and Tunable Anisotropy of Nanoscale Friction in Graphene.

The nanoscale friction between an atomic force microscopy tip and graphene is investigated using friction force microscopy (FFM). During the tip movement, friction forces are observed to increase and then saturate in a highly anisotropic manner. As a result, the friction forces in graphene are highly dependent on the scanning direction: under some conditions, the energy dissipated along the armchair direction can be 80% higher than along the zigzag direction.

Short-term response of human osteoblast-like cells on titanium surfaces with micro- and nano-sized features.

Since the way that human bone cells behave on contact with different surfaces topographies seems to be crucial to osseointegration, the aim of the present study is to evaluate the participation of some micro- and nanosized features of Ti surfaces in the short-term response of primary human osteoblast-like cells (HOC). Surfaces were prepared as ground (G-Ti), hydrofluoric acid etched (HF-Ti), and sandblasted/HF-etched (SLA-Ti), and analyzed using both three-dimensional (3D) profilometer and atomic force microscope (AFM). Cell morphology was assessed using scanning electron microscopy (SEM) after 4 and 24 h in culture.

Surface roughness in ceramics with different finishing techniques using atomic force microscope and profilometer.

This study assessed the finishing and polishing of 3 ceramic materials: Vitadur Alpha, IPS Empress 2 and AllCeram. Surface modification techniques were selected to simulate dental practice. Forty-five specimens of each ceramic were divided into 5 groups of 9 specimens, which were finished using the following procedures: Group 1--glaze; Group 2--glaze, grinding and subsequent polishing with the Eve system; Group 3--glaze, grinding and subsequent polished with the Identoflex system; Group 4--glaze followed by polishing with Identoflex; Group 5--glaze, grinding and subsequent polishing with Shofu kit.