SUMMARY

Energy landscape theory provides the most comprehensive description for all the physical, chemical and biological interactions. However, there are few experimental methods capable of directly measuring the energy landscape of specific interactions. Force probes are the one experimental tool to measure the strength and physical extent of interfacial and intermolecular interactions at nanometer scales or level of single molecules. However, the stochastic nature of force measurements requires a massive quantity of data to obtain meaningful energetic information of the interaction. Moreover, existing models often presume the shape of the energy landscape thus preventing the experimental probing of complex interactions with multiple binding/unbinding steps. The goal of this research is to enable full reconstruction of energy and force landscape of arbitrary interactions at single-molecular/nanometer scale. To understand the fundamental physics of interfacial and intermolecular interactions, a comprehensive framework to describe force spectroscopy without presumed models is developed. In this thesis, I will apply this framework to Develop a thermally modulated force spectroscopy (TM-FS) technique utilizing white-noise excitation to create cantilever’s fluctuation that is similar to high equivalent temperature. Along with a Boltzmann based equilibrium analysis, I will demonstrate the method can reconstruct the underlying energy landscape of strong, single-well interactions. Secondly, to overcome the restriction of the energy landscape reconstruction developed in the first aim, I will develop a novel sampling method to directly reconstruct the force landscape without the assumption made in the energy landscape reconstruction method. Lastly, I will apply the newly developed framework and excitation methods to study the formation of water capillary bridge at physical interfaces.