Endurance behavior of conductive yarns

• Bending fatigue causes failure of the conducting Cu-wires in photonic textiles.
• The location of failure is the transition region from rigid to flexible parts.
• The results are modeled with the Coffin–Manson relation.
• The results enable to estimate the endurance under various bending stress conditions.

Various companies are industrializing ‘photonic’ textiles for medical and architectural applications. Here we report reliability testing of photonic textiles based on woven textiles with integrated copper-based conductive yarns used to drive attached LEDs. These textiles were subjected to cyclic mechanical stress tests and the cycle life was analyzed in terms of fatigue. Results show that failure is due to wire fractures at the transition from the rigid component to the compliant textile. The results are in good agreement with Cu-fatigue data from literature. This shows that it is possible to estimate the lifetime of electronic textiles under use conditions by the mechanical fatigue of the conducting yarn material properties.