Dynamic characterization of nanoelectromechanical oscillators by atomic force microscopy

Dynamic detection of vibrational characteristics of nanoelectromechanical systems (NEMS) was investigated through direct coupling with a micromechanical probe. The nanomechanical structures were harmonically driven using piezoelectric transducers and the resulting out-of-plane excitations were monitored with a conventional atomic force microscope (AFM) probe. Intermittent contact imaging data show quantitative linear classical resonance behavior. Additionally, noncontact AFM interrogation revealed the initiation of interaction between the two oscillators, providing a qualitative description of the resonant response. The vibrational spectra measured through optical excitation and detection were in good agreement with the coupled NEMS-AFM system measurement results. The dynamic response of the coupled system was modeled through a combination of long range van der Waals and contact forces using the Derjaguin-Muller-Toporov model. These results collectively demonstrate that this is a viable method for detecting the dynamic behavior of nanoscale suspended mechanical structures.(c) 2007 American Institute of Physics.