In Situ Resistance Measurements of Strained Carbon Nanotubes

TL;DR

This study measures how multi-walled carbon nanotubes respond electrically to mechanical strain, revealing contact resistance effects, fracture behavior, and tunable resistance in broken tubes, advancing understanding of their mechanical-electrical properties.

Contribution

It provides new insights into the electrical response of strained carbon nanotubes, including contact resistance effects and the ability to tune resistance after breaking.

Findings

Contact resistance dominates in some samples.

Tubes can be fractured without resistance change.

Resistance can be tuned after breaking.

Abstract

We investigate the response of multi-walled carbon nanotubes to mechanical strain applied with an Atomic Force Microscope (AFM) probe. We find that in some samples, changes in the contact resistance dominate the measured resistance change. In others, strain large enough to fracture the tube can be applied without a significant change in the contact resistance. In this case we observe that enough force is applied to break the tube without any change in resistance until the tube fails. We have also manipulated the ends of the broken tube back in contact with each other, re-establishing a finite resistance. We observe that in this broken configuration the resistance of the sample is tunable to values 15-350 kW greater than prior to breaking.