ABSTRACT
In recent years, nanoscale materials (i.e., thin films, nanowires, nanotubes, etc.) have gained significant technological interest thanks to their outstanding intrinsic properties compared to those of bulk materials. The knowledge of their nanomechanical properties is extremely important to identify potential application areas. However, mechanical measurements of freestanding nanoscale objects are quite challenging due to the difficulties encountered in the setup of standard tensile or bending tests. Recently, several methods based on the use of atomic force microscopy (AFM) have been developed to study the mechanical behavior of nanostructured materials (Salvetat et al., 1999a; Wong et al., 1997; Yu et al., 2000). As an example, AFM has been used in contact mode to carry out three-point bending tests on nanotubes and nanowires suspended on nanoporous membranes or on silicon substrates (Cuenot et al., 2000; Ni et al., 2006; Niu et al., 2007; Salvetat et al., 1999b; Wu et al., 2005). In this configuration, the one-dimensional nanomaterial is considered as a beam (clamped or simply supported) lying over a pore and the vertical deflection is measured as a function of the force applied midway along the suspended length.
