Strain sensing behaviour of elastomeric composite films containing carbon nanotubes under cyclic loading

The resistivity response under cyclic loading of thermoplastic polyurethane (TPU) multi-walled carbon nanotube (MWNT) elastomeric nanocomposite films fabricated by a solution process with good nanotube dispersion and low percolation threshold (pc ∼ 0.35 wt.%) is reported. At a strain amplitude of 5%, the strain-dependent resistance shows good recoverability and reproducibility after stabilisation by cyclic loading. When larger strains are applied, only a small part of the resistance is recoverable, and a double peak appears when a single loading cycle is applied. This behaviour is attributed to the competition of network deformation and network reformation during cyclic loading of the polymer composites.