Highly sensitive and durable wearable strain sensors from a core-sheath nanocomposite yarn

With fiber-based wearable electronics being developed and widely used in various fields, the safety and durability of nanomaterials in fibrous system become big concerns due to the leakage of nanomaterials and possible failure in functionality. To date, it is still challenging to fabricate wearable strain sensors with sensitivity and durability. Herein, we report a simple strategy for large-scale fabrication of core-sheath nanocomposite yarn (CSCY) based wearable sensor with high sensitivity and superior durability. By dispersing aqueous CNT ink into braided composite yarns as the core (BYs-CNT) and electrospun polyurethane (PU) nanofibers as the sheath, a unique core-sheath micro-nanofibrous structure was fabricated to grant the yarn with extremely high sensing sensitivity (maximum GF up to 980), long-term stability and great durability (against washing and dilute hydrochloric acid). The as-developed CSCY strain sensor was demonstrated to monitor real-time subtle and vigorous human activities. The present work provides insights for developing reliable and stable, highly sensitive, flexible and durable wearable electronics with potential applications in different areas.