Mechanical forces on small scales provide valuable and detailed information on the properties of the probed surface, such as wear, friction and adhesion. Understanding the role of dissipation energy and surface potential in frictional mechanisms is essential for tribology, nanoscale fabrication, catalysis and so on. Through the interaction between the sharp Atomic Force Microscope (AFM) cantilever tip and the surface, various forces can be measured during the scanning experiment, and disclose information in the atomic-resolution. We are interested in the application of nonequilibrium work relations (such as the Jarzynski equility) to reconstruct the surface potential from such atomic friction measurements of mono-crystals and catalysts. One of the main objective of this research is to study surface potential of catalysts in order to optimize their performance in the production of renewable fuels.
Single molecule force spectroscopy.
In recent years single molecule force spectroscopy techniques have evolved considerably, becoming an important measure in addition to traditional bulk methods. While ensemble bulk measurements study the averaged properties of a system, single molecule measurements illuminate the tails of these properties’ distributions. Atomic force microscopy (AFM), which has the ability to detect subtle details at sub-nanometer resolution, can hold a single protein for long periods of time, thus exploring a wide spectrum of forces ranging from a few to thousands of pico-Newtons. The single protein recorded force traces disclose its mechanistic features, such as reaction rates, diffusion coefficients, unfolding/refolding dynamics, free-energy landscapes available to perform work and conformational transition. We focus our interest on exploring proteins and polymers phase-transitions in the presence of co-solutes with the intention to provide new information about the physical-chemistry aspects of the specific ion phenomenon.