Stretchable Carbon Nanotube-Polymer Composites with Homogenous Deformation and as Liquid Droplet Sensors

Carbon nanotubes have the potential to develop functional and stretchable nanocomposites; tailoring the mechanical property especially enabling uniform deformation at large strains is key to those applications. Here, continuously woven are single-walled carbon nanotubes (SWNTs) through a poly(vinyl alcohol) (PVA) solution into a highly flexible and processable composite film combining the reinforcing effect of SWNTs and high stretchability of PVA matrix. Observed is a homogenous strain field distribution throughout the composite film during tensile tests until large strains of 300-358% with a local fluctuation of only 10% that of total strain, also exhibiting consistent transverse and longitudinal true strains as well as Poisson's ratio. This property further leads to highly sensitive and electrical response to attached liquid droplets including water, NaCl solution, and typical organic solvents, in original and stretched states for many cycles, owing to the tunable SWNT networks within the polymer matrix upon volume expansion or shrinkage. The continuously fabricated SWNT/PVA composites with high stretchability and uniform deformation have potential applications in stretchable/weavable electronics, sensors, and actuators.