Related Experiment Video
Updated: Jun 12, 2026
13:15
Quantitative and Qualitative Examination of Particle-particle Interactions Using Colloidal Probe Nanoscopy
Published on: July 18, 2014
11.0K
Molecular Probing of the Microscopic Pressure at Contact Interfaces
Chao-Chun Hsu1, Allen Chu-Hsiang Hsu2, Chun-Yen Lin2
1van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
Journal of the American Chemical Society
|May 2, 2024
Summary
Researchers developed a new fluorescence microscopy method using molecular probes to map local pressure distribution in contacts. This technique bridges nanoscale friction studies with real-world applications where surface roughness is critical.
Area of Science:
- Tribology
- Materials Science
- Nanotechnology
Background:
- Friction is crucial in many systems, from transportation to seismology.
- Understanding nanoscale friction requires simultaneous measurement of contact area and local pressure.
- Current methods struggle to accurately map pressure distribution at the nanoscale.
Purpose of the Study:
- To develop a novel method for simultaneous measurement of real contact area and local pressure distribution.
- To bridge the gap between nanoscale friction studies and macroscopic friction behavior.
- To enable visualization of pressure distribution in multiasperity contacts.
Main Methods:
- Utilized planarizable molecular probes that change conformation under pressure.
- Employed fluorescence microscopy to detect pressure-induced spectral shifts (bathochromic and hyperchromic).
- Established a linear relationship between fluorescence intensity and nanoscale pressure.
Main Results:
- Demonstrated a linear correlation between fluorescence intensity and simulated pressure at the submicron scale.
- Successfully mapped local pressure distribution in mechanical contacts.
- Validated the method for depicting pressure distribution in multiasperity contacts.
Conclusions:
- The developed method provides a new approach to study friction at the nanoscale.
- This technique allows for the translation of nanoscale insights into macroscopic friction behavior.
- The method is valuable for understanding systems where surface roughness significantly impacts friction.
Related Concept Videos
03:13Intermolecular Forces
Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions (attractive or repulsive) between charged species (permanent, partial, or temporary charges) and exist with varying strengths between ions, polar, nonpolar, and neutral molecules. The different types of intermolecular forces are ion–dipole, dipole–dipole, hydrogen bonds, and dispersion; among these, dipole–dipole, hydrogen bonds, and dispersion...
02:28Intermolecular Forces in Solutions
The formation of a solution is an example of a spontaneous process, a process that occurs under specified conditions without energy from some external source.
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Such a solution is called an ideal solution. A mixture of ideal gases (or gases such as helium and argon,...
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Such a solution is called an ideal solution. A mixture of ideal gases (or gases such as helium and argon,...
03:13Intermolecular Forces
Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions (attractive or repulsive) between charged species (permanent, partial, or temporary charges) and exist with varying strengths between ions, polar, nonpolar, and neutral molecules. The different types of intermolecular forces are ion–dipole, dipole–dipole, hydrogen bonds, and dispersion; among these, dipole–dipole, hydrogen bonds, and dispersion...
02:56Intermolecular Forces and Physical Properties
01:13Contact Angle
When a solid is dipped inside a liquid, the liquid surface becomes curved near the contact. For some solid–liquid interfaces, the liquid is pulled up along the solid, while for others, the liquid surface is convex or depressed near the solid surface. This phenomenon can be explained using the concept of cohesive and adhesive forces.
The adhesive force is the molecular force between molecules of different materials, that is, between the molecules of the solid and the liquid. The cohesive force...
The adhesive force is the molecular force between molecules of different materials, that is, between the molecules of the solid and the liquid. The cohesive force...
01:24Surface Tension
Surface tension is defined as the force per unit length (γ) acting along the surface of a liquid. It arises due to strong intermolecular forces of attraction. A molecule located inside the bulk of the liquid is surrounded by other molecules and experiences equal forces in all directions. However, a molecule at the surface experiences unbalanced forces because there are more neighboring molecules below than above. This creates a net inward force that pulls surface molecules toward the interior,...