In search of an improved strategy to form low-resistance contacts to semiconducting transition metal dichalcogenides, we combine ab initio density functional electronic structure calculations for an NbSe2/WSe2 interface with quantum transport measurements of the corresponding heterojunction between a few-layer WSe2 semiconductor and a metallic NbSe2 layer. Our theoretical results suggest that, ...

Frictional contacts lead to the formation of a surface layer called third body, consisting wear particles and structures resulting from their agglomerates. Its behavior properties at nanoscale control macroscopic tribological performance. It is known that topography evolve with time mutually influence one another. However, mature body largely uncharted territory its early stages are unknown. He...

The tribological properties of two smooth surfaces in the presence of a thin confined film are investigated with a generic model for the interaction between two surfaces and with computer simulations. It is shown that at large normal contact pressures, an ultra thin film automatically leads to static friction between two flat surfaces-even if the surfaces are incommensurate. Commen-surability i...

We propose a novel complementarity model for a general three-dimensional manipulation system with rolling and sliding contacts to solve the forward dynamics problem. The key idea is to derive complementary constraints for a rolling contact by decomposing the tangential properties. We also discuss the existence and uniqueness of a solution to the model, and algorithms for solving the problem. We...

The main challenge in predicting sliding friction is related to the complexity of highly nonequilibrium processes, the kinetics of which are controlled by the interface temperature. Our experiments reveal a nonmonotonic enhancement of dry nanoscale friction at cryogenic temperatures for different material classes. Concerted simulations show that it emerges from two competing processes acting at...

Topological entanglements in polymers are mimicked by sliding rings (slip links) that enforce pair contacts between monomers. We study the force-extension curve for linear polymers in which slip links create additional loops of variable sizes. For a single loop in a phantom chain, we obtain exact expressions for the average end-to-end separation. The linear response to a small force is related ...

The efficient planning of contact tasks for intelligent robotic systems requires a thorough understanding of the kinematic constraints im on the system by C l J form analytic eolutionrr for the poeition and orientation of a pamive polygon moving in contact with two or three active polygonrr whoee itions and orientations are independently c o n t r o l E This is done by applying elimination tech...

We study the effect of the anisotropy induced by loading on the elastoplastic response of a two dimensional discrete element model granular material. The anisotropy of the contact network leads to a breakdown of the linear isotropic elasticity. We report on a linear dependence of the Young moduli and Poisson ratios on the fabric coefficients, measuring the anisotropy of the contact network. The...

Using high-resolution X-ray scattering techniques, we measure the variation, q(x), of the position in reciprocal space of the CDW satellite, in the sliding state, along the length of NbSe3 whiskers. We show that structural defects and intentionally X-ray radiation-damaged regions increase locally the CDW pinning force, and induce CDW phase distortions which are consistent with those observed ne...

Boron carbide (B4C) has been studied under dry sliding conditions for use as a potential finite-life run-in coating. Such a coating has been found to polish its mating surface during dry sliding wear, thereby providing fatigue resistance to the coated part. Employing such run-in coatings requires a complete understanding of the changes that occur in the coating abrasiveness during the polishing...