5. Conclusions and outlook

The use of spherical nano-indentation has enabled us to reproduce the mechanical stresses of MEMS microrelays and analyze their impact on the contact surfaces of thin gold layers. In this way, the link between adhesion forces and topography, via the Fuller parameter, is highlighted. The use of the latter can lead to design rules for contact surfaces (figure 26 ). For example, for asperities with a mean radius of curvature of 350 nm, the standard deviation of the height distribution of the vertices must be greater than 3 nm (figure 26 ).