Effect of silica aerogel incorporation on electrical characteristics and strain-sensing capability of nano-porous CNT/PDMS sensors

The present study focuses on investigating the effect of incorporating silica aerogel on the electrical characteristics and sensing capabilities of carbon nanotube (CNT)-embedded PDMS nanocomposites. Initially, the concept of developing nanohybrid clusters composed of CNT and silica aerogel was introduced, followed by comprehensive evaluations of their formation including zeta potential, Raman spectra and FT-IR spectrum. Subsequently, the nanocomposites with varied silica aerogel contents from 0.5 to 2 % by polymer mass were assessed for their sensing capability. It is observed that porosity has exerts perceptible influence on the overall effective electrical conductivity of the sensor below the percolation thresholds, while it does not have any impact beyond this threshold. In addition, the effective medium proposition theory has been modified to analyze both the effective electrical conductivity and the piezoelectric properties of the sensors fabricated. Based on the theoretical and experimental results, the developed CNT@aerogel nanohybrid clusters displayed the potential to enhance sensing sensitivity and increase linearity during stretching condition.