Transparent Strain Sensors Through Randomly Self-Assembly of Single Walled Carbon Nanotubes at the Air/Water Interface

Abstract

Transparent, stretchable strain sensors have numerous applications in structural health monitoring, smart clothing, human motion detection etc. In this research, we reported a versatile, simple method for transparent, stretchable strain sensors based on sandwich structure of single-walled carbon nanotube (SWCNT) network and polydimethylsiloxane (PDMS) substrate. The SWCNT network showed isotropy due to the surfactant driven random self-assembly at air/water interface. The SWCNT film of 2 layers presents high transparency (>90%) and great conductivity (12.1 kΩ/cm2) without strain. During first 50 cycles of stretching/releasing, the resistance increased due to the irrecoverable loss of junctions between nanotubes. After 50th cycle, the conductivity of SWCNT thin film remains stable and shows good linearity due to the strong inter-bundle junctions.