Growth of Industry 4.0 and other smart technologies has increased the demand for high-performance sensors in applications such as industrial safety measures, human health monitoring, and wearable electronics. This thesis focuses on developing polymer nanocomposite flexible strain sensors and sustainable carbon nanocomposite-based gas sensors.
The first part of the thesis presents an approach to achieve the stable dispersion of nanofillers without sacrificing their inherent characteristics through polymer functionalization. Two opposite-charged Polystyrene sulfonate sodium (PSS) and Poly-diallyl-dimethyl-ammonium chloride (PDDA) are used to functionalize the different nanofillers such as carbon nanotubes (CNT) and hydrogen exfoliated graphene (HEG). The influence of different polymer functionalization of nanofillers on the flexible strain sensing performance is evaluated, and the significance of selecting suitable polymers for functionalization is highlighted.
In the second part of the thesis, a design framework for polymer nanocomposite flexible strain sensor tape, which cares the manufacturing scalability, packaging feasibility and end-user installation issues, was developed. Numerical simulation is carried out to analyze the impact of adhesive coating and optimize the PVDC-co-VC/PSS-CNT polymer nanocomposite to achieve efficient strain sensing performance. A scaled-up long flexible strain sensor tape with a controlled, uniform adhesive thickness and copper contact pad was developed, demonstrating repeatability and reproducibility.
The third part explores sustainable material manufacturing and green electronics by conversion of invasive alien plant species Prosopis juliflora leaves into a useful carbon material. The characteristics and implications of Prosopis juliflora biomass carbon (PJBMC) are studied, and biomass carbon nanocomposites decorated with SnO2 nanoparticles are evaluated for hazardous gas sensing applications. The uniform distribution of nanoparticles enables gas adsorption and desorption, leading to efficient NO2 gas sensor development.