Strain-Dependent Electrical Properties of a Conductive MWCNT/PEO Composite Film

摘要

Multiwalled carbon nanotubes (MWCNT) were combined with polyethylene oxide (PEO) to make a series of conductive MWCNT/PEO composite films containing different volume fractions of MWCNT. Samples from the different loadings of MWCNT were bonded onto the surface of a dogbone-shaped polycarbonate substrate. This substrate allowed the film to be stretched through a large strain range (0.07) using a conventional uniaxial test machine. Unique and repeatable relationships in resistance versus strain were obtained for multiple samples with different volume fractions of MWCNT. The overall pattern of electrical resistance change versus strain for the samples of each volume fraction of MWCNT consists of linear and non-linear regions. A model to describe the combination of linear and non-linear modes of electrical resistance change as a function of strain is suggested. The unique characteristics in electrical resistance change for different volume fractions implies that nanotube composites can be used as tunable strain sensors for application into embedded sensor systems in structures.