Excellent piezoresistivity of composites made from networked carbon nanotubes and polydimethylsiloxane: An intertube barrier driven strain sensing

Composites made from multi-walled carbon nanotubes and polydimethylsiloxane exhibit an excellent piezoresistivity at elastic limits where strain sensitivity reaches 0.93–0.96 and resistance changes due to stretching and compressing matches with loading histograms. Resistance change becomes pulse-like as the samples are bent and/or twisted, attributed to the rapid increase in intertube spacing. Straining induces movements and segmentations of tube aggregates with tube mobility ranging at 0.1–90 nm/s. Intertube barrier driven sensing mechanism is viscoelasticity related and is therefore interpreted on the basis of spring-dashpot models.