Evaluation of Mechanical Properties

Mechanical properties such as elastic modulus, fracture stress, and yield stress of nano/micromaterials are fundamental data for practical design of nano/micromaterial-based devices. These properties generally differ from those of bulk material because of size effects. This chapter is devoted to an introduction of some techniques for evaluating the mechanical properties of nanowires and thin wires. In order to clarify the advantages of the techniques that we introduce, the first section gives an overview of typical techniques reported so far. In the subsequent sections, we take up atomic force acoustic microscopy using a concentrated-mass cantilever and a bending method based on the geometrically nonlinear problem on the bent shape, i.e., elastica, for evaluating elastic modulus and bending strength of brittle nanowires. Finally, evaluation of elastic–plastic properties of metallic thin wires is demonstrated by means of unsymmetrical, small-span bending test.