One of the main current challenges in nanosciences is the exploitation of single molecular machines for mechanical applications in the real world. In the proposed project, molecular design, chemical synthesis, theory and STM experiments will be combined to investigate the mechanical properties of single molecular rotors and motors for which we can trigger and control a unidirectional rotation. We will first design and synthesize prototypes of nanowinch integrating our motor capable of towing a large panel of "nanoloads" on a surface. Covering a broad range of loads will allow us to determine the effective mechanical work delivered by this molecular motor. If validated, this strategy could be generalized to test other electrically-addressed molecular motors. In a second part, we will develop original strategies to explore the use of double-decker coordination complexes and polyaromatic hydrocarbons with star-shaped geometries as molecular gears. These studies will be performed on metallic surfaces at very low temperature and on semi-conducting surfaces at room temperature. The transfer of a rotation movement in a train of gears, as well as the laws governing the mechanics of such movements, will be studied.