Related Experiment Video
Updated: Mar 23, 2026
09:21
Experiments on Ultrasonic Lubrication Using a Piezoelectrically-assisted Tribometer and Optical Profilometer
Published on: September 28, 2015
13.1K
A new tribological experimental setup to study confined and sheared monolayers
L Fu1, D Favier1, T Charitat1
1UPR22/CNRS, Institut Charles Sadron, Université de Strasbourg, 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2, France.
The Review of Scientific Instruments
|April 3, 2016
Summary
We developed a novel experimental setup to measure friction and velocity of nanoscale layers. This setup aids in understanding fluid dynamics in confined layers for lubrication and polymer friction applications.
Area of Science:
- Tribology
- Nanotechnology
- Fluid Dynamics
Background:
- Understanding friction at the nanoscale is crucial for lubrication and material science.
- Directly measuring the velocity of confined layers during sliding has been a significant challenge.
Purpose of the Study:
- To present an original experimental setup for simultaneous measurement of friction coefficient and velocity of nanoscale confined layers.
- To demonstrate the setup's accuracy in investigating nanometer-scale sliding layers.
Main Methods:
- Coupling tribology, velocimetry, and direct contact visualization.
- Utilizing a rigid spherical indenter sliding on a flat surface at constant speed.
- Studying a model lipid monolayer on glass slides to validate the setup.
Main Results:
- The setup successfully measures the apparent friction coefficient and velocity of confined layers down to the molecular scale.
- Demonstrated accuracy in capturing information from a nanometer-thick sheared zone.
Conclusions:
- The developed experimental setup is effective for investigating nanoscale sliding layers.
- This setup will advance the understanding of hydrodynamic effects in confined layers relevant to lubrication, biolubrication, and polymer friction.
Related Concept Videos
01:23Design Example: Deciding Thickness of Lubricating Fluid in a Shaft
386
Effective lubrication between a rotating shaft and its bearing housing is essential in rotating machinery to minimize friction, wear, and energy loss. With carefully controlled thickness and viscosity, the lubricant layer prevents metal-to-metal contact, ensuring smooth operation.
To calculate the required thickness of the lubricant layer, the tangential velocity at the shaft's surface must first be determined. This velocity is calculated by converting the rotational speed to angular velocity...
To calculate the required thickness of the lubricant layer, the tangential velocity at the shaft's surface must first be determined. This velocity is calculated by converting the rotational speed to angular velocity...
386
01:17Steady, Laminar Flow Between Parallel Plates
982
Understanding steady, laminar flow between parallel plates is essential for analyzing and designing flow in narrow rectangular channels, commonly found in various water conveyance and drainage systems. The Navier-Stokes equations govern fluid motion and are generally challenging to solve due to their nonlinearity. However, simplifications are possible in certain cases, like the steady laminar flow between parallel plates. For this scenario, we assume steady, incompressible, laminar flow.
982
01:18Shearing Stress
2.4K
Shearing stress, denoted by the Greek letter tau (τ), is stress caused by forces acting transversely on an object. These forces create internal ones within the entity in the plane where the external forces are applied. The resultant of these internal forces is the shear in the section.
The average shearing stress can be calculated by dividing the shear by the area of the cross-section.
The average shearing stress can be calculated by dividing the shear by the area of the cross-section.
2.4K