Flexible Resistance-Type Strain Sensors toward Monitoring Finger Movements

Flexible strain sensors with superior flexibility and high sensitivity are critical to artificial intelligence, and it is favorable to develop highly sensitive strain sensors by simple and cost-effective methods. We have prepared carbon-nanotubes-enhanced thermal polyurethane nanocomposites with good mechanical and electrical properties for the fabrication of highly sensitive strain sensors. The nanomaterials were prepared through a simple but effective solvent-evaporation method, and cheap polyurethane was used as the main raw material. Only a small quantity of carbon nanotubes (mass content 5%) was doped into a polyurethane matrix with aim of enhancing the mechanical and electrical properties of the nanocomposite. The resulting flexible nanocomposite films show a highly sensitive resistance response under an external strain stimulus. Strain sensors based on these flexible composite films deliver excellent sensitivity and conformality under mechanical conditions, and can detect finger movements precisely at various bending angles. © 2021 Royal Society of Chemistry. All rights reserved.