Abstract
The recent advent of high-resolution imaging and force spectroscopy using atomic force mi- croscopy (AFM) in organic and inorganic solutions opens the way to imaging a wide variety of surfaces and their solvent structure. However, to take full advantage of the high resolution and provide signicant new analytical capability, a detailed understanding of the background contrast mechanisms that lead to atomic and molecular resolution is critical. Without a theory that connects the measured force to atomic models of the surface and tip of the microscope, the information that can be distilled from these measurements is limited. Molecular dynamics simulations show that the forces acting on the microscope tip result from the direct interaction between a tip and a surface and are entirely due to the structure of water around the tip and surface.