Any macroscopic deformation of a filamentous bundle is necessarily accompanied by local sliding and/or stretching of the constituent filaments. Yet the nature of the sliding friction between two aligned filaments interacting through multiple contacts remains largely unexplored. Here, by directly measuring the sliding forces between two bundled F-actin filaments, we show that these frictional fo...

coeffcient of  friction  (cof)  for  rubber parts  is one of  the key parameters in their interaction with solid rough surfaces (micrometer to millimeter scales),  such  as  tire-road  interactions. cof  of  rubber  depends  on  viscoelastic properties of rubber, roughness characteristics of the counter-part surface, and process variables such as contact nominal pressure and sliding speed. due ...

We investigate the effective friction encountered by a mass sliding on a granular layer as a function of bed thickness and boundary roughness conditions. The observed friction has minima for a small number of layers before it increases and saturates to a value that depends on the roughness of the sliding surface. We use an index-matched interstitial liquid to probe the internal motion of the gr...

The sliding interfaces found in the body— within the eyes, the digestive system, and the articulating joints, for example—are soft and permeable yet extremely robust, possessing low friction. The common elements among these systems are hydrophilic biopolymer networks that provide physical surfaces, elasticity, and fluid permeability. Stiff, impermeable probes are traditionally used to assess th...

Internally Architectured Materials (IAMs) that exhibit different friction forces for sliding in the opposite directions are proposed. This is achieved by translating deformation normal to the sliding plane into a tangential force in a manner that is akin to a toothbrush with inclined bristles. Friction asymmetry is attained by employing a layered material or a structure with parallel 'ribs' inc...

Friction and wear are detrimental to engineered systems. Ultrasonic lubrication is achieved when the interface between two sliding surfaces is vibrated at a frequency above the acoustic range (20 kHz). As a solid-state technology, ultrasonic lubrication can be used where conventional lubricants are unfeasible or undesirable. Further, ultrasonic lubrication allows for electrical modulation of th...

In the paper, a low friction pneumatic cylinder and a sliding table, and both of them are embedded with aerostatic bearings are designed. A low friction pneumatic table is constructed by combining the pneumatic cylinder and the sliding table. The characteristics for the friction force versus velocity of the pneumatic cylinder and the pneumatic table are measured. Moreover, a hybrid self-tuning ...

It is shown that the exhibition of smooth sliding and relaxation oscillations, or 4 stick-slips under conditions of boundary lubrication, when frictional forces are measured by the deflexion of an elastic system, may be explained as due to the dependence of kinetic friction on velocity. In the cases giving smooth sliding, kinetic friction decreases as velocity decreases, at very low speeds; for...

Planning t>he motion of bodies in cont,act requires a model of contact rnechanics in order to predict sliding, rolling, and jamming. Such a model t'ypi-cally includes estimates of the coefficients of friction. Though, usually assumed t,o be constant, these coefficients vary and are difficult to measure. In this paper, we treat, the coefficient,s of friction as independent variables and derive r...

Understanding friction between material pairs is very crucial when utilizing the materials in various applications, including mechanical and biological systems. In the present investigation, efforts were made to study the influence of surface texture and roughness on friction and transfer film formation during sliding of Ultra High Molecular Weight Polyethylene (UHMWPE) pins against steel plate...