The use of a carbon nanotube sensor for measuring strain by micro-Raman spectroscopy

We present a Raman spectroscopy study on a film of carbon nanotubes (CNTs) acting as a wireless sensor for measuring strain at the microscale. A model for the CNT strain sensor was proposed by evaluating the quantitative contributions of individual deformed CNTs to the entire Raman spectrum. The proposed model provides an analytical relationship between the in-plane strain components to be measured and the spectral parameters detected directly through polarized Raman tests on the CNT film sensor. Based on this model, a noncontact technique for strain measurements is developed. The experiments using this technique confirmed that the CNT strain sensor described is appropriate for measuring the in-plane strain components at the microscale by using polarized Raman spectroscopy.