A Comparative Study of Compressible and Conductive Vertically Aligned Carbon Nanotube Forest in Different Polymer Matrixes for High-Performance Piezoresistive Force Sensors.

In present scenario, conducting and light weight flexible polymer nanocomposites rival metallic and inorganic semiconducting materials as highly sensitive piezoresistive force sensors. Herein, we explore the feasibility of vertically aligned carbon nanotube (VACNT) nanocomposites impregnated in different polymer matrixes, envisioned as highly-efficient piezoresistors in sensor applications. Polymer nanocomposites are selectively designed and fabricated using three different polymer matrixes, i.e. polydimethylsiloxane (PDMS), polyurethane (PU) and epoxy resins with ideal reinforcement of VACNTs to enhance the thermal stability, conductivity, compressibility, piezoresistivity and sensitivity of these nanocomposites. To predict the best piezoresistive force sensor the structural, optical, thermal, electrical, mechanical and piezoresistive properties of the nanocomposites are evaluated using field emission scanning electron microscopy (FESEM), x-ray diffraction (XRD), Raman spectroscopy, thermogravimetric analysis (TGA), I-V measurements, compressive stress-strain measurements, hysteresis, sensitivity and force studies. The results demonstrate that the PDMS/VACNT nanocomposite is capable of sustaining large force with almost complete recovery and enhanced sensitivity, thereby fulfilling the desirable need of highly-efficient conductive and flexible force sensor as compared to PU/VACNT and epoxy/VACNT nanocomposites.