Mechanical and electrical response models of carbon nanotubes

Carbon nanotubes have remarkable mechanical and electrical properties. One promising feature is their electrical resistance that strongly depends on mechanical deformation. This, in combination with the fact that nanotubes can be dispersed into polymeric matrices, makes them ideal constituents for the development of novel multifunctional materials and devices. When dispersed into an insulating polymer, nanotubes are known to induce conductive behavior to the composite. This is attributed to the formation of conductive nanotube networks due to percolation. When a nanocomposite is mechanically deformed, load is transferred to the nanotubes, as well. As they deform and rearrange, their electrical properties change and the percolation networks are distorted. This effect is studied in this chapter using three models: (i) an atomistic molecular mechanics approach for prediction of the mechanical response of carbon nanotubes, (ii) a subatomic tight-binding approach for prediction of the piezeoresistive response of individual carbon nanotubes, and (iii) a homogenized microscale model for prediction of the piezoresistive response of carbon nanotube doped insulating polymers. Results seem to be in agreement with experimental results for small deformations. © Springer Science+Business Media Dordrecht 2013.