Flexible strain sensors with superior flexibility and high sensitivity are critical to artificial intelligence. And it is favorable to develop highly sensitive strain sensors with simple and cost effective method. Here, we have prepared carbon nanotubes enhanced thermal polyurethane nanocomposites with good mechanical and electrical properties for fabrication of highly sensitive strain sensors. The nanomaterials have been prepared through simple but effective solvent evaporation method, and the cheap polyurethane has been utilized as main raw materials. Only a small quantity of carbon nanotubes with mass content of 5% has been doped into polyurethane matrix with purpose of enhancing mechanical and electrical properties of the nanocomposites. As a result, the flexible nanocomposite films present highly sensitive resistance response under external strain stimulus. The strain sensors based on these flexible composite films deliver excellent sensitivity and conformality under mechanical conditions, and detect finger movements precisely under different bending angles.
