NanoElectroMechanical Systems (NEMS) have critical structural elements at or below 100 nm. This distinguishes them from MicroElectroMechancial Systems (MEMS), where the critical structural elements are on the micrometer length scale. Compared to MEMS, NEMS combine smaller mass with higher surface area to volume ratio and are therefore most interesting for applications regarding high frequency resonators and ultrasensitive sensors.