A. Siddika, AC. Mills
North Carolina State University,
United States
Keywords: electronic textiles, textile interconnects, conductive threads and wires, ZSK embroidery , EMG armband
Summary:
The integration of reliable electrical interconnects into textiles is a critical challenge for developing wearable electronic systems. Conventional textile-based interconnect fabrication techniques, including printed conductive traces and traditional embroidery using conductive threads, often suffer from cracking, limited mechanical durability, and loss of conductivity under repeated deformation and laundering. In traditional embroidery machines, conductive threads are repeatedly stitched through the textile substrate, exposing them to high tensile forces, cyclic bending, and vertical motion, which can lead to yarn breakage, increased electrical resistance, and reduced reliability. This work presents an alternative approach to embroidered interconnect fabrication using a ZSK embroidery machine, allowing the direct integration of conductive threads or fine metallic wires as functional interconnects with reduced mechanical stress. In the ZSK embroidery process, the conductive threads or wires are laid onto the textile surface and mechanically secured using a non-conductive bobbin thread, rather than being stitched through the fabric itself. This fabrication strategy significantly minimizes strain, bending, and tension on the conductive element during embroidery, facilitating the use of conductive threads and wires that are otherwise unsuitable for conventional embroidery processes. The interconnect architecture is digitally defined and fully customizable using EPCwin software, providing precise control over interconnect geometry and achieving a fully automated, scalable manufacturing process without manual intervention. The technique is compatible with both woven and knitted textile substrates, broadening its applicability across diverse wearable electronic textile platforms. Compared to printed interconnects, the ZSK embroidered interconnect is expected to exhibit improved mechanical robustness, wash durability, and electrical stability. To assess the practical performance of this interconnect technology in a wearable application, an electromyography (EMG) armband is fabricated, where the copper wires are employed as interconnects and integrated onto single jersey knit fabrics using the ZSK embroidery process. To evaluate washability and durability, the EMG armband will be subjected to three standard washing cycles. Electrical resistance measurements will be performed before and after washing to assess the impact of laundering on interconnect performance. In addition to that, the EMG armband will be evaluated before and after washing to assess signal quality and functional performance. This study demonstrates a robust, scalable, and high-performance textile interconnect fabrication method that addresses the key limitations of conventional embroidered and printed approaches. The ZSK-embroidered interconnect technology offers enhanced mechanical durability, wash resistance, and electrical stability, making it well-suited for a wide range of wearable electronic textile applications that require long-term reliability and consistent performance.