Recent progress in simulating the properties of interfacial water at hard hydrophobic and hydrophilic surfaces is reviewed and compared to results for the air/water interface. The authors discuss static properties such as the equilibrium contact angle, the depletion layer thickness, and the orientation of interfacial water molecules. Relations between these properties, e.g., the relation betwee...

Sliding friction across a thin soft lubricant film typically occurs by stick-slip, the lubricant fully solidifying at stick, yielding and flowing at slip. The static friction force per unit area preceding slip is known from molecular dynamics (MD) simulations to decrease with increasing contact area. That makes the large-size fate of stick-slip unclear and unknown; its possible vanishing is imp...

This paper focuses on the problem of force-feedback for the human-operator hand when manipulating virtual objects. We propose a method for the computation of feedback-forces that have to be applied on each individual phalanx and nger of the human hand in order to display pertinent, kinesthetic information about static or dynamic characteristics of objects present in the virtual scene. External ...

In this paper we announce some new mathematical results on the stability of quasistatic paths of a single particle linearly elastic system with Coulomb friction and persistent normal contact with a flat obstacle.A quasi-static path is said to be stable at some value of the load parameter if, for some finite interval of the load parameter thereafter, the dynamic solutions behave continuously wit...

A prototypical problem in the study of wetting phenomena is that of a solid plunging into or being withdrawn from a liquid bath. In the latter, dewetting case, a critical speed exists above which a three-phase contact line is no longer sustainable and the solid can no longer remain dry. Instead, a liquid film is being deposited on the solid. Demonstrating this transition from a dry to a wetted ...

The stick-to-slip transition of a fingertip in contact with a planar surface does not occur instantaneously. As the tangential load increases, portions of the skin adhere while others slip, giving rise to an evolution of the contact state, termed partial slip. We develop a quasi-static model that predicts that if the coefficient of kinetic friction is larger than the coefficient of static frict...

We report on frictional strengthening (healing) in granular quartz gouge as a function of time of true stationary contact. To distinguish between the slip-dependent [Ruina, 1983] and time-dependent [Dieterich, 1979] friction constitutive laws, we designed tests similar to conventional slide-hold-slide (SHS) tests except that shear load was completely removed prior to holds. We find large healin...

When voltage is suddenly applied to vertical, parallel dielectric-coated electrodes dipped into a liquid with finite conductivity, the liquid responds by rising up to reach a new hydrostatic equilibrium height. On the microfluidic scale, the dominating mechanism impeding this electromechanically induced actuation appears to be a dynamic friction force that is directly proportional to the veloci...

Rodents use their whiskers to locate nearby objects with an extreme precision. To perform such tasks, they need to detect whisker/object contacts with a high temporal accuracy. This contact detection is conveyed by classes of mechanoreceptors whose neural activity is sensitive to either slow or fast time varying mechanical stresses acting at the base of the whiskers. We developed a biomimetic a...

Static stiffness is an important indicator of the performance of a rolling guide, having direct influence on the stiffness and precision of computer numerically controlled (CNC) machine tools. After preloading the rolling guide, an outward elastic deformation is generated at the carriage skirt, which leads to a decrease in the static stiffness of the rolling guide. Therefore, there would be rel...