Strain Sensing in Polymer/Carbon Nanotube Composites by Electrical Resistance Measurement

Abstract

In this work multiwall carbon nanotubes (MWCNTs) dispersed in a polymer matrix have been used for strain sensing of the resulting nanocomposite under tensile loading. This was achieved by measuring the relative electrical resistance change (ΔR/R 0 ) in conductive PVDF (Polyvinylidenefluoride)/MWCNT nanocomposites prepared by melt-mixing with varying filler content from 1.25wt% to 8wt%. The samples were subjected to tensile loading and the longitudinal strain was monitored together with the longitudinal electrical resistance. The results showed that CNTs dispersed in an insulating polymer matrix have the potential to be used as a sensitive network to monitor or predict the damage in polymer/carbon nanotube nanocomposites.

Study of the reinforcing mechanism and strain sensing in a carbon black filled elastomer

“…1. A non-contact experimental method, based on a laser extensometer was employed for detailed strain measurement [20]. The maximum value of strain applied during the tensile experiments was 60% for materials.…”

“…This filler content is above the percolation threshold but not very far from it, making the nanocomposite sensitive enough to monitor low strain changes, because a relatively low strain change can result in a more significant alteration of resistance change. It is generally accepted that the higher sensitivities observed for filler contents close to the percolation threshold is attributed to the more prominent changes of the sparse filler network [20,34]. The breakage of a contact in a sparse network has a higher impact on the electrical resistance than if happened in a dense network.…”

Nano-enhanced composite materials under thermal shock and environmental degradation: A durability study

“…This concept provides the potential to combine benefits of the nanoscale reinforcement, such as sensing abilities and toughness, with the functionality of well-established fiber composites [5][6][7][8][9][10][11][12][13].…”

Detection of damage in cylindrical parts of carbon fiber/epoxy composites using electrical resistance (ER) measurements

“…Generally the changes in the ER signal due damage in such conductive materials has been under tensile loading [7][8][9][10].The "probes" used in the ER method need to have very good adhesion between the probes and the specimen in which the displacement are relatively small [11,12]. Flexural and compression loading, on the other hand, may produce larger shape changes and potentially unstable ER signals [13][14][15].…”