In this paper a method for MEMS (micro-electromechanical systems) lubrication consisting in chemical grafting of long alkyl chains onto silica is proposed. In a first step, we have compared chemical grafting with other methods of layer fabrication such as Langmuir-Blodgett films and self-assembled monolayers. In a second step, various monomolecular layers were grafted on the silica surface, in order to study the influence of the chain length and chemical structure on lubrication. Friction tests were performed on a reciprocating tribometer in a sphere on plane geometry. The plane specimen was the surface of treated silica wafers. The coefficient of friction is lowered from 0.6 for bare silica to a minimum of 0.07, depending on the lubricant monolayer.