A crucial factor when developing e-textiles is ensuring their robustness and functionality during everyday activities, particularly washing. The ability to launder e-textile garments is not merely a matter of convenience but a necessity for widespread adoption. Incorporating electronics into textiles can lead to damage due to mechanical and chemical stresses, which most electronics are not designed to withstand. This work focuses on electronic yarn technology (e-yarn), in which electronic functionality is added to textiles by embedding small electronic components into a flexible yarn-like structure. First, the component is soldered onto thin conductive wires. The soldered component is then enclosed in a protective polymer resin (micro-pod). Micro-pods have different diameters depending on the size of the embedded electronic component. The ensemble is finally covered in a textile sheath. This study focuses on the wash durability of e-yarns integrated with textiles in three different ways: embroidered onto the surface of a woven fabric, within a knitted channel in a knitted fabric, and woven as a weft yarn. Further, the work studied the impact of using different sizes of micro-pods on the e-yarns’ wash durability. Ultimately, good wash durability was observed under all testing conditions.

This study presents a standalone yarn-level assessment of the mechanical and functional durability of polymer-encapsulated electronic yarns (E-yarns) for wearable electronic textile applications. The investigated E-yarns consisted of miniaturised electronic components soldered onto fine conductive wires, protected by polymer encapsulation, and enclosed within braided textile yarn structures. This heterogeneous architecture enables textile-compatible functionality but creates local regions that may be susceptible to damage under various deformation modes. E-yarns incorporating light-emitting diode, photodiode, and resistor components were evaluated under cyclic bending fatigue, torsional fatigue, quasi-static tensile loading, and wash durability conditions. Electrical measurements were used to monitor functional degradation and failure, while X-ray imaging, scanning electron microscopy and finite element analysis were used to examine structural damage, failure localisation, fracture surface morphology, and local stress and strain distribution. The results show that E-yarn durability depended on the imposed loading condition, with distinct mechanical and functional responses observed across the different test modes. The polymer-encapsulated region emerged as a mechanically important feature of the E-yarn architecture, particularly at transitions between encapsulated and non-encapsulated regions. By addressing multiple deformation and loading conditions at the standalone yarn level, this work provides a systematic reliability assessment of polymer-encapsulated E-yarns, enabling intrinsic failure mechanisms to be distinguished from textile integration effects and supporting the development of more reliable yarn-based electronic textiles.