We report on a new method to characterize nano-hydrodynamic properties at the liquid/solid interface relying solely on the measurement of the thermal motion of confined colloids. Using Fluorescence Correlation Spectroscopy (FCS) to probe the diffusion of the colloidal tracers, this optical technique --equivalent in spirit to the microrheology technique used for bulk properties-- is able to achieve nanometric resolution on the slip length measurement. It confirms the no-slip boundary condition on wetting surfaces and shows a partial slip b=18 +/- 5 nm on non-wetting ones. Moreover, in the absence of external forcing, we do not find any evidence for large nano-bubble promoted slippage on moderately rough non-wetting surfaces.
@article{arxiv.cond-mat/0507054,
title = {Probing the nanohydrodynamics at liquid-solid interfaces using thermal motion},
author = {L. Joly and C. Ybert and L. Bocquet},
journal= {arXiv preprint arXiv:cond-mat/0507054},
year = {2015}
}