This thesis aims to provide the latest progresses on the experimental investigation of friction and adhesion phenomena, occurring at the nanoscale in microelectromechanical systems (MEMS). I have studied and characterized the interaction between MEMS sidewalls in contact and sliding one onto another. Ultrananocrystalline diamond (UNCD) and aluminum oxide have been tested and utilized for the fabrication and integration process in MEMS micro-tribotesters. The results of this research are new in the field of nanotribology, and interesting for the development of micro-devices that can allow sliding surfaces in their operations.