Coating Glass Fibre Yarn with Conductive Materials for Real-Time Structure Sensing

Abstract

Nowadays, the demand for glass fibre-reinforced polymers (GFRPs) has increased in the industry owing to their low weight, high strength, corrosion resistance and low cost compared with other fibre-reinforced polymer composites. However, GFRP is anisotropic material with low interlaminar strength where the damage can occur without warning. Integrating a real-time damage detection process can mitigate this problem. Therefore, this paper presents the initial fabrication of an embedded capacitive sensor into the GFRP by using conductive electrodes inbetween its layers. To form the sensing electrodes, glass fibre yarns were coated with conductive material and braided into the fibregalss woven fabric. Two coating methods were considered to form embedded electrodes in this work which include aerosol spray coatings that were carbon based and gold-based physical vapour deposition, (PVD). It has been shown that spray coating has a weak bond and the carbon particles disperse during the molding process. In the PVD technique the nanoparticle (Au) distributed uniformly along the fibres and has a good resistance (≈100Ω). The capacitive sensor based on gold coating was exaimined using a three point bending test which demonstrate linear response toward the flexural load with a sensitivity of 25.1 fF/N.

Structural Health Monitoring of Fiber Reinforced Composites Using Integrated a Linear Capacitance Based Sensor

“…Two different materials of filament yarn, namely glass and Kevlar fiber, were considered in this investigation. Various conductive coating techniques were evaluated, and physical vapor deposition (PVD) was selected as the appropriate coating technique, based on previous work [31]. PVD was chosen for its lower operational temperatures, which are vital for avoiding thermal degradation of the fibers and ensuring their continued structural and functional integrity [32].…”

“…Additionally, Figure 2i displays images of cured laminates with lateral sensor configurations for glass fiber-reinforced polymer composites. To verify that the problems encountered in prior studies [31], specifically the dispersion of spray carbon coating within the epoxy resin, were not repeated, a gold-coated glass fiber yarn filament embedded in an epoxy resin matrix underwent visual inspection via microscopy post-curing, as depicted in Figure 3e. This examination, carried out using an OLYMPUS MX61L microscope, (Tokyo, Japan), confirmed that the gold coating remained intact without dispersal.…”