Department of Materials Science & Metallurgy: Research paper of the month

Department of Materials Science & Metallurgy

Research paper of the month

May 2015 - Piezoresistive Effect in Carbon Nanotube Fibres

The complex structure of the macroscopic assemblies of carbon nanotubes and variable intrinsic piezoresistivity of nanotubes themselves lead to highly interesting piezoresistive performance of this new type of conductive material. Here, we present an in-depth study of the piezoresistive effect in carbon nanotube fibres, i.e., yarn-like assemblies made purely of aligned carbon nanotubes, which are expected to find applications as electrical and electronic materials. The resistivity changes of carbon nanotube fibres were measured on initial loading, through the elastic/plastic transition, on cyclic loading and on stress relaxation. The various regimes of stress/strain behaviour were modelled using a standard linear solid model, which was modified with an additional element in series to account for the observed creep behaviour. On the basis of the experimental and modelling results, the origin of piezoresistivity is discussed.

Figure: Graphical abstract as published in ACS Nano. The behaviour of CNT fibre under stress/strain was for the first time modelled using a modified standard linear solid model, which allowed much better insight into the origin of piezoresistive effect in the fibres.

A. Lekawa-Raus, K. K. Koziol, A.H. Windle, “Piezoresistive Effect in Carbon Nanotube Fibres” ACS Nano, 8 (2014) 11214–11224

doi: 10.1021/nn503596f