Facile and scalable fabrication of stretchable flame-resistant yarn for temperature monitoring and strain sensing

Electronic textiles with functions of temperature monitoring and human motion detection have attracted considerable interest, especially those which can be operated under extreme conditions such as high temperature. However, the restricted working conditions and poor stretchability have limited the practical application of most reported electronic textiles. Herein, we report a facile and scalable strategy to fabricate flame-resistant sensing yarn with a core-sheath structure for temperature monitoring and strain sensor applications via a large-scale spinning technique. The hierarchical yarn comprises a spandex filament as the core, carbon nanotube (CNT)-coated aramid fibers as the middle layer, and aramid fibers as the sheath. The obtained spandex/ CNT@Aramid/Aramid (SCAA) yarn exhibited stretchability up to 160 % with excellent thermal resistance, outstanding thermal insulation performance, and temperature monitoring ability within a wide-range of 50-400 degrees C. Additionally, SCAA-based textiles showed excellent strain sensing performance in a wide operating temperature range (0-300 degrees C). Based on the above, a SCAA-based textiles which can transmit high-temperature alarms through active (stretching) and passive (thermosensation) modes was designed, enabling temperature monitoring presenting at extremely high temperatures. We believe this work will contribute to the development of practical sensing e-textiles towards applications in harsh environment.