Stability analysis of double-walled carbon nanotubes as AFM probes based on a continuum model

The instability of single-walled carbon nanotubes (SWCNTs) under compressive loading has been observed experimentally by TEM and may limit their performance and structural integrity as atomic force microscopy (AFM) tips. Double-walled carbon nanotubes (DWCNTs) with inner and outer nanotubes of different lengths are proposed as AFM probes, and a theoretical approach based on a nanobeam model is developed for investigating the critical buckling stress of the DWCNTs under an axial compressive load. The influence of structural parameters on the buckling stress of DWCNT AFM probes are analyzed using this approach. The results show that the influence of the length mismatch between inner and outer nanotubes, as well as buckling modes on the buckling stress of DWCNTs was significant.