Reinforced standing multi-walled carbon nanotube film for stretchable strain sensor

To meet the requirements of flexible and wearable electronic devices, strain sensors with high sensitivity, stretchability and reliability are essential prerequisite. In this work, we developed a strain sensor of resistance type, which is composed of standing multi-walled carbon nanotube (MWCNT) network, reinforced by PDMS film. Benefiting from the standing MWCNT network structure, the strain sensors show high-sensitivity not only in high strain but also in the low strain region (<; 10%). In addition, the designed sensor can overcome the nonlinearity defect. The performance of the proposed strain sensors can be controlled by varying the length and density of the as-grown carbon nanotube (CNT) samples. By adjusting the CNT samples, a gauge factor up to 4.5 was achieved. Besides, the strain sensors also show high stretchability, with strain up to 120%. Finally, we utilized the sensors to detect the motions of human fingers, demonstrating their high performance in applications.