Mechanical resonators are attractive for many applications in signal processing and sensing applications [1]. However, the aggressive scaling of their dimensions into the nanometer range with a simultaneous increase of the resonance frequency makes their direct measurement extremely difficult with electrostatic transduction, due to the very low signal level. Novel current modulation mechanisms, such as the FET based detection [2,3,4] and piezoresistive [5,6] current modulation, demonstrated the most promising results for highly sensitive motion detection in Nano-Electro-Mechanical (NEM) resonators. © 2010 IEEE.