NEMS (Nanoelectromechanical Devices) have been of particular interest in recent years due to a growing set of new applications they offer in domains such as sensitive charge detection, mass sensing and biological imaging. Their size, being reduced down to the nanometer-scale, allows high operating frequencies. Applications in the Gigahertz range have been demonstrated. With devices operating faster the sensitivity is improved. As an example, a sensitivity of 12 Zn/p Hz12 zN⁄√Hz (1zN=〖10〗^(-21) N) N) has been achieved using a carbon nanotube resonator. Moreover, NEMS have very low operating power and high quality factors.