The rapid development of the micro & nanomechanical industry has stimulated the need and design of molecular assemblies capable to impart new functional surface properties to materials or improve those existing, for the control of their interface behaviors (adsorption, condensation, wetting, lubrication, adhesion, liquid ﬂow). Self-assembled monolayers (SAMs) have played and still continue to play a major role in the achievement of this goal. For such small devices, the control of adhesion and friction between the moving surfaces is crucial. Indeed the surface-to-volume ratios in these micro-and nanoscale devices are so large that adhesive and friction forces dominate gravitation and inertia. Thus, the basis for molecular design and tailoring of SAMs must include a complete knowledge of interrelationships between the molecular structure and frictional properties of SAMs, as well as an understanding of friction of SAMs at a molecular level.