Waste‐to‐Wearables: Stretchable Sensors from Discarded Mask Straps for Real‐Time Motion Detection

Abstract In the post‐pandemic era, face masks remain a crucial measure for preventing the spread of influenza and airborne pathogens. Among their components, discarded elastic straps pose a significant environmental threat due to their non‐biodegradability, potential for wildlife entanglement, and fragmentation into microplastics. Despite the aforementioned limitations, the straps, predominantly consisting of spandex and polyester yarns, exhibit superior mechanical resilience and flexibility, thereby underscoring their potential as reliable candidates for integration into advanced wearable sensing platforms. Herein, a simple drop‐coating and drying approach is presented to deposit a conductive poly(3,4‐ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS)/PVA/pullulan composite onto these elastic straps, yielding ultra‐flexible, stretchable, and highly conductive wearable sensors. The resulting devices demonstrate outstanding mechanical properties, including stretchability beyond 100%, a gauge factor of 3.43, and durability over 1000 cycles. These sensors enable real‐time monitoring of various human joint motions, including finger, wrist, elbow, and knee bending, offering a sustainable strategy to upcycle pandemic‐related polymer waste into high‐performance components for next‐generation wearable electronics.