Local solvation shell measurement in water using a carbon nanotube probe

Combining a carbon nanotube probe and a highly sensitive dynamic measuremen t scheme has enabled us to use atomic force microscopy to measure oscillato ry forces in water on approaching a surface that has been laterally charact erized on a nanometer scale. This opens up the possibility of investigating water layers under a variety of experimental conditions and as a function of precise lateral position on any surface including biological membranes a nd macromolecules. Among the many and varied roles of water layers are effe cts on biomolecular adhesion, colloid dispersion, and tribology, which can now be investigated with nanometer lateral resolution and with a wider rang e of materials than that previously provided by surface forces appartus.