Integrating Flexible Filament Circuits for E‐Textile Applications

Practical wearable e‐textiles must be durable and retain, as far as possible, the textile properties such as drape, feel, lightweight, breathability, and washability that make fabrics suitable for clothing. Early e‐textile garments were realized by inserting standard portable electronic devices into bespoke pockets and arranging interconnects and cabling across the garment. In these examples, the textile merely served as a vehicle to house the electronics and had no inherent electronic functionality. A reduction in electronic component size, the development of flexible circuits, and the ability to weave robust interconnects offer the potential for improved levels of electronic integration within the textile. The weaving of electronic circuit filaments less than 2 mm wide into fabrics such that the electronics are fully concealed in the textile and given extra protection by the surrounding textile fibers is introduced. The failure mechanisms for different filament circuit designs before and after integration into the textile are investigated with a 90° cyclical bending test. Results show that encapsulated filament circuits embedded within the textile survive 45 washing cycles and more than 1500 cycles of 90° bending around a bending radius of 10 mm, performing five times better than equivalent filament circuits before integration into the fabric. An electronic textile that completely conceals the presence of any integrated electronic functionality from the wearer is produced by weaving traditional textile fibers/yarns with electronic filament circuit prototypes consisting of reprogrammable temperature sensors and digitally controlled LED lighting. The textile fibers disguise the filaments in bespoke pockets that enhance durability of filaments during the bending and washing of the e‐textile.