Paper Title
A Flexible Strain Sensor Design Based on Ny-6 Yarn Coated With Ag Nanoparticles for Real Time Strain Monitoring Application

Abstract
Composites show better performance than traditional materials however, they are inclined to damage formation, delamination, or fracture. So, it is necessary to detect damage or crack formation with in time in these materials to avoid any catastrophic incident. Therefore, numerous researchers have been developing in-situ sensors and monitoring systems for composite structures. The objective of this study is to create a microscale, flexible strain sensor wire for real-time sensing applications. This strain sensor wire was developed by depositing conductive silver (Ag) nanoparticles on the surface of Ny-6 untwisted yarn using electroless plating process to achieve uniform conductive coating over each filament of the Ny-6 polymer. The electro-mechanical behavior of this Ny/Ag sensor wire was verified experimentally and gauge factor was found to be in range of 62-69. This flexible Ny/Ag sensor wire was then integratedwith in a composite sample to validate the monitoring of deformation and detection of damage initiation. Experimental procedure was performed where the mechanical behavior of the composite sample was tested in a standard tensometer machine, while the electrical signal of the Ny/Ag sensor wire was recorded. The results showed that the electrical response of the sensor was correlated perfectly with the mechanical behavior of the specimen. This indicated that Ny/Ag strain sensor wire can be used for real-time damage detection and structural health monitoring (SHM) applications. Keywords- Composites, Structural health monitoring, Conductive Ag-metal coating, Microscale strain sensor wire, Electro-mechanical response