Noncontact friction and force fluctuations between closely spaced bodies

The measurement of noncontact friction between closely spaced bodies was performed at various temperatures. Analysis was performed between Au(111) and gold-coated cantilever using Brownian motion and cantilever damping observations. The force fluctuations were interpreted in terms of near-surface fluctuating electric fields using the fluctuation-dissipation theorem. The importance of inhomogeneous contact potential was discussed in comparison with measurements over dielectric surfaces.