A study on the morphology of thin copper films on para-aramid yarns and their influence on the yarn’s electro-conductive and mechanical properties

Abstract

The latest technological advances in new materials and devices enabled wearable systems to be created by utilizing textile solutions. These solutions require electro-conductive yarns as a basic component. Although the production of electro-conductive yarn is widely reported, research is still necessary to characterize them to advance their electro-conductive and mechanical properties. Hence, we served this need and characterized copper-coated para-aramid yarns produced by an in-house developed electroless deposition method. In this paper we present our investigation on the yarn’s copper layer characteristics after deposition. Furthermore, we looked, in depth, at the yarn’s electro-conductive properties before and after washing as well as their mechanical properties before and after copper deposition. We found a dependency of the copper layer morphology on its deposition time. This is directly correlated to the resulting layer thickness and hence to the yarn’s electro-conductive properties, demonstrating the autocatalytic nature of the coating process. Above that, the electro-conductive properties of the coated yarn linearly decrease with washing cycles. Furthermore, the copper coating impairs the yarn’s mechanical properties decreasing its specific stress at break by 30%.

Characterization of electro-conductive textile materials by its biaxial anisotropy coefficient and resistivity

“…R s = ∕h The resistances R 1 and R 2 , the modulus k determined from Eqs. (10) and (12) and the resistivity ρ calculated from Eqs. (9) and (11) for circular sample and square-shaped sample respectively, the surface resistance R s calculated from Eqs.…”

“…Electrical conductivity of flat textile materials results from the electrical conductivity of their components i.e. fibers and threads [11][12][13][14]. It is obvious that electrical conductivity depends on textile material structure.…”

Digital inkjet functionalization of water-repellent textile for smart textile application

“…During wash fastness testing, the functional layer starts to change after 10 domestic washes. Schwarz et al [36] produced thin copper films on para-aramid yarns via wet chemistry route. The morphology of yarns shows damage after 25 washes.…”

Analysis of resistance to bending of metal electroconductive layers deposited on textile composite substrates in PVD process

“…The production of elastic electronics is possible in spray coating processes using carbon nanotubes, graphene flakes or nanofibers, electroless plating, sputtering, physical vacuum deposition, plasma coating or digital printing 4,[8][9][10][11][12][13] . To fabricate the electroconducting elements on or in textile substrates the varied methods are usually used: the embroidery 14 , dip coating 15 , electrospinning 16 , electroless plating 17,18 , ink-jet or screen printing method 19,20 , thin metallic wires or yarns 3 , metal-coated fibres 21,22 , conductive fibers produced by doping intrinsically conductive polymers 23 , the fibers with metallic core and the outer polymer coating, and even with the liquid metal core 24 , sputtering [25][26][27] or chemical and physical vacuum deposition 2,7 . The 3D printing method is also used to direct deposition of electroconductive architectures on textiles.…”