Graphene‐Functionalized Carbon Nanotubes for Conducting Polymer Nanocomposites and Their Improved Strain Sensing Properties

Functionalization of carbon nanotubes (CNTs) is essential for the dispersion of CNTs in polymer matrices due to their inherence. However, conventional functional groups are insulating in nature, thereby destroying the basic structure of the CNTs and their electrical conductivity due to the harsh and long‐period acid treatments. Hence, a new method of functionalization is essential. In this article, a poly(vinyliedene fluoride) (PVDF) composite comprising graphene wrapped CNTs as a conducting filler is described. A strain‐gauge factor of ≈20 at low strain levels (0.1%) is with a 3 wt% graphene wrapped CNT hybrid in PVDF, which overwhelms conventional metal foil strain gauges as well as functionalized CNT or functionalized graphene based polymer composites for strain sensing.