Ultrasensitive Strain Sensor Based on Separation of Overlapped Carbon Nanotubes

TLDR

Stretchable strain sensors have improved, yet scalable fabrication that delivers both high sensitivity and stretchability remains challenging. This study presents a stretchable strain sensor using overlapped carbon‑nanotube bundles integrated with silicone elastomer. The sensor is fabricated by line‑patterning vertically aligned CNT bundles, rolling and transferring them onto silicone elastomer, and operates through sliding and disconnection of the overlapped CNTs. It achieves a broad range (≥145 % strain) with an ultrahigh gauge factor of 42 300 at 125–145 % strain, excellent repeatability and durability, and its performance can be tuned by adjusting the overlapped CNT area, making it suitable for wearable healthcare applications.

Abstract

Abstract Although there have been remarkable improvements in stretchable strain sensors, the development of strain sensors with scalable fabrication techniques and which both high sensitivity and stretchability simultaneously is still challenging. In this work, a stretchable strain sensor based on overlapped carbon nanotube (CNT) bundles coupled with a silicone elastomer is presented. The strain sensor with overlapped CNTs is prepared by synthesizing line‐patterned vertically aligned CNT bundles and rolling and transferring them to the silicone elastomer. With the sliding and disconnection of the overlapped CNTs, the strain sensor performs excellently with a broad sensing range (≥145% strain), ultrahigh sensitivity (gauge factor of 42 300 at a strain of 125–145%), high repeatability, and durability. The performance of the sensor is also tunable by controlling the overlapped area of CNT bundles. Detailed mechanisms of the sensor and its applications in human motion detection are also further investigated. With the novel structure and mechanism, the sensor can detect a wide range of strains with high sensitivity, demonstrating the potential for numerous applications including wearable healthcare devices.