Influence of the axial compression on the natural frequency of AFM probes using double-walled carbon nanotubes with different wall lengths

摘要

Carbon nanotubes (CNTs) appear to be ideal tip materials of atomic force microscopy (AFM) due to their small diameter and high stiffness. In this study, double-walled carbon nanotube (DWCNT) structures with different lengths of inner and outer layers are proposed as AFM tips. Both the vibration response and mode shapes of the tipped nanotubes under axial compression are studied by a theoretical nanobeam model. The results show that the natural frequencies of DWCNTs are significantly affected by the com-pressive loads and the length difference between the inner and outer nanotubes. The natural frequency associated with certain vibrational modes decreases with increasing com-pressive loads. This research may provide a useful reference for practical design for AFM tips with CNTs.