Carbon nanotube fibers as torsion sensors

Carbon nanotube fibers possess the ability to respond electrically to tensile loading. This research explores their electrical response to torsional loading; results demonstrate that applied twist compacts the fiber, resulting in increased electrical contact between carbon nanotubes. Shear strains in excess of 24% do not result in permanent changes in electrical resistance along uninfused fibers, while irreversible changes in electrical resistance arise from applied shear strains of 12.9% in epoxy infused fibers. Bulk shear modulus is approximated to be 0.40±0.02GPa for unreinforced and 2.79±0.64GPa for infused fibers.