Design and manufacturing of electrically conductive composites via microvascular channels

Tanabi, Hamed
Owing to their tunable properties and wide range of applications, conductive composites are one of the most important, interesting, and active areas in advanced composite research. For instance, among numerous types of health-monitoring and damage-sensing sensors that can be integrated into composites, electrically conducting sensors offer a simple, cost-effective, and durable option for structural health monitoring in fiber reinforced composites. Despite these advantages, the development of internal electrical sensors in composite systems is limited due to sensitivity and reliability of the sensor. The unique electrical and mechanical properties of carbon nanotubes (CNTs) render CNT reinforced nanocomposites as potentially attractive materials for strain-sensing and monitoring purposes in various industries. The dispersion state of CNT’s in polymeric matrix has a significant role on the physical and the mechanical properties of the resulting CNT reinforced nanocomposites. In this study, a series of experiments was designed to investigate the effect of dispersion process parameters and CNT concentration, as well as their interactions on electrical and mechanical and strain sensing properties of CNT-epoxy nanocomposites. Composite samples were produced under different CNT-resin dispersion conditions based on a design of experiments approach, and were characterized using tensile testing, conductivity measurements and micrography. Also, electrical conductivity of the fabricated nanocomposites was improved with aligning of nanotubes under a magnetic field. In order to create electrical conductive networks in composite specimens, hollow micro-channels were made using vaporization of sacrificial components and then were filled with CNT-epoxy conductive filler. The use of such conductive pathways for in situ strain monitoring of a composite specimen was also investigated. It was found that the strain sensitivity of the prepared conductive channels is nearly two times of conventional strain sensors.
Citation Formats
H. Tanabi, “Design and manufacturing of electrically conductive composites via microvascular channels,” Ph.D. - Doctoral Program, Middle East Technical University, 2017.