The field of micro/nanoelectromechanical systems (MEMS/NEMS) has grown drastically over the last decade. Applications in which MEMS/NEMS elements have taken part include sensors, microactuators, accelerometers, RF switching arrays, probe-based data storage, micro cantilevers, molecular gears and biological motors. Because the surface-to-volume ratio is high, and MEMS elements generally operate under light load conditions, surface forces, such as adhesion and friction, play an important role in their performance, particularly the performance of the systems with elements that move relative to each other. MEMS, therefore, requires materials and surfaces that avoid stiction as well as reduce friction and wear.
Since silicon is a traditional material for MEMS, but it does not have good tribological properties, its surface needs to be treated in order to increase the reliability and the operating lifetime. For this purpose, various surface modifications, including chemical and topographical modifications, have been developed and utilized effectively. Among the chemical modification, lubricant thin films like self-assembled monolayers (SAMS) or perfluoropolyether (PFPE) are popular treatments. In recent years, topographical modification, including the patterning and the transferring of tailored structures, has attracted scientists and triblogists worldwide as an effective method to enhance the tribological properties of engineered surfaces.