Development of Advanced Conductive Polymer Composite Yarns for Multifunctional Electronic Textile Applications in Nigerian Healthcare and Wearable Technology Markets

Conductive polymer composite yarns capable of transmitting electrical signals while maintaining textile flexibility and processability are foundational to the emerging electronic textile and wearable technology market. This research develops novel conductive polymer composite yarns through systematic investigation of composite formulation, spinning technology, and yarn architecture optimisation, targeting healthcare monitoring and interactive wearable applications in the Nigerian market. Carbon nanotube and graphene nanoplatelet fillers were systematically incorporated into thermoplastic polyurethane and polyamide matrices at loadings from 1 to 15 percent by weight. Composite fibres were produced by melt spinning and wet spinning routes, with post-spinning drawing applied to develop fibre orientation and electrical percolation network alignment. The effect of filler type, loading, aspect ratio, and spinning parameters on electrical conductivity, tensile properties, and electromechanical behaviour under cyclic strain was characterised. Gauge factor for strain sensing and temperature coefficient of resistance for temperature sensing were determined. Yarn integration into knitted and woven structures was evaluated for signal transmission quality, textile processability, and wash durability. An original model relating percolation network connectivity to electrical conductivity as a function of strain state was developed and experimentally validated. Results demonstrate electrical conductivities of 12 to 340 S/m achievable in melt-spun composite fibres depending on filler type and loading. Gauge factors of 2.1 to 8.4 were achieved for strain sensing yarns, suitable for body motion capture applications. Temperature coefficient of resistance of minus 0.8 to minus 1.6 percent per degree Celsius was measured, enabling body temperature monitoring. The research establishes a comprehensive scientific basis for developing conductive yarn manufacturing capabilities in Nigeria's textile engineering sector. Keywords: conductive polymer composite, electronic textile, yarn spinning, strain sensing, healthcare wearable