Sliding contacts in liquid environments: A nanotribology study

• Applicant: Professor Dr. Gianaurelio Cuniberti, since 8/2021
• Subject Area: Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 445400600

Understanding the influence of the surrounding environment on the sliding friction between two solid surfaces in liquids is of utmost importance for applications to MEMS/NEMS or colloidal systems as well as to shed light on the dynamics of formation and rupture of single contact junctions. In this project we aim to perform an experimental investigation of the mechanical properties of contacts formed by sharp silicon tips on sodium chloride, silica, calcite, and molybdenum disulfide using friction force microscopy. The sample surfaces will be exposed to electrolite acqueous solutions to explore specific-ion effects all along the Hofmeister series, and to polar and nonpolar solvents (ethanol, acetone, dichlorobenzene, etc.) with varying viscosities. The different interaction potentials will be quantitatively reconstructed from the time variations of the friction forces acting on the tip with an original method proposed by one of the applicants (RB) and recently applied to reconstruct the free energy landscape of protein unfolding under mechanical load. The results so obtained will be compared to complementary information available with dynamics AFM techniques.

• DFG Programme: Research Grants
• International Connection: Israel
• International Co-Applicant: Professor Ronen Berkovich, Ph.D.
• Cooperation Partner: Dr. Assaf Yaakobovitz
• Ehemaliger Antragsteller: Professor Enrico Gnecco, Ph.D., until 8/2021