Role of OH Termination in Mitigating Friction of Diamond-like Carbon under High Load: A Joint Simulation and Experimental Study.

Diamond-like carbon (DLC) has recently attracted much attention as a promising solid-state lubricant because it exhibits low friction, low abrasion, and high wear resistance. Although we previously reported the reason why H-terminated DLC exhibits low friction based on a tight-binding quantum chemical molecular dynamics (TB-QCMD) simulation, experimentally, the low-friction state of H-terminated DLC is not stable, limiting its application. In the present work, our TB-QCMD simulations suggest that H/OH-terminated DLC could give low friction even under high loads, whereas H-terminated DLC could not.

Non-Empirical Law for Nanoscale Atom-by-Atom Wear.

Wear of contact materials results in energy loss and device failure. Conventionally, wear is described by empirical laws such as the Archard's law; however, the fundamental physical and chemical origins of the empirical law have long been elusive, and moreover empirical wear laws do not always hold for nanoscale contact, collaboratively hindering the development of high-durable tribosystems. Here, a non-empirical and robustly applicable wear law for nanoscale contact situations is proposed.

Triboemission of hydrocarbon molecules from diamond-like carbon friction interface induces atomic-scale wear.

Understanding atomic-scale wear is crucial to avoid device failure. Atomic-scale wear differs from macroscale wear because chemical reactions and interactions at the friction interface are dominant in atomic-scale tribological behaviors, instead of macroscale properties, such as material strength and hardness. It is particularly challenging to reveal interfacial reactions and atomic-scale wear mechanisms.

Tight-Binding Quantum Chemical Molecular Dynamics Study on the Friction and Wear Processes of Diamond-Like Carbon Coatings: Effect of Tensile Stress.

Diamond-like carbon (DLC) coatings have attracted much attention as an excellent solid lubricant due to their low-friction properties. However, wear is still a problem for the durability of DLC coatings. Tensile stress on the surface of DLC coatings has an important effect on the wear behavior during friction.

Fate of methanol molecule sandwiched between hydrogen-terminated diamond-like carbon films by tribochemical reactions: tight-binding quantum chemical molecular dynamics study.

Recently, much attention has been given to diamond-like carbon (DLC) as a solid-state lubricant, because it exhibits high resistance to wear, low friction and low abrasion. Experimentally it is reported that gas environments are very important for improving the tribological characteristics of DLC films. Recently one of the authors in the present paper, J.

Tribological properties of single-walled carbon nanotube solids.

Binder-free single-walled carbon nanotube (SWCNT) solids were evaluated for solid lubrication applications. The steady-state friction coefficients (mu) for the SWCNT solids were found to reach values as low as 0.22-0.

Ear injury caused by a sticky-tipped applicator.

We here report a relatively rare case of traumatic injury of the tympanic membrane caused by a sticky-tipped applicator as well as some characteristics of this sticky-tipped applicator that were examined experimentally. This rare case was very unusual in that the injury was caused by external force applied from the medial to lateral direction during very careful cleaning (no unexpected force). Although removal of cerumen by a sticky substance seems to be an excellent idea, the present case shows that the stickiness that facilitates removal of the cerumen may be dangerous for thin, dry skin such as the tympanic membrane.