Flexible strain sensors based on carbon nanotubes and silver nanowires and polydimethylsiloxane

Abstract

Flexible strain sensors with varied architectures were fabricated via depositing mixtures or stacked layers of AgNWs and SWCNT/MWCNT onto PDMS substrates. A comprehensive investigation was conducted to uncover how sensor construction and materials impact the conductivity of the sensing layer, along with key performance metrics such as sensitivity, linearity, hysteresis, and repeatability. A systematic exploration was then carried out to analyze the effect of the sensor structure and materials on the sensing layer’s conductivity, as well as its sensitivity, linearity, hysteresis, and repeatability. Experimental results show that the sensor with a MWCNT (inside)-AgNWs (surface) stacked structure showcases outstanding capabilities. In the range of 0–100% tensile strain, it shows a high sensitivity (GF = 0.98), a low nonlinear error of 2.97%, and an ultrafast response time of 0.122 s. After subjecting it to 150 strain cycles, the sensitivity only drops to 0.996. Moreover, it can precisely detect finger motions across angles of 0°, 30°, 60°, 90°, and 120°. These advantages suggest that the sensor holds great potential for applications in wearable controllers and motion detection fields.