Bioinspired Wettability Engineering Enables Efficient Exhaled Breath Condensate Harvesting for Wearable Respiratory Monitoring

Efficient collection of exhaled breath condensate (EBC) remains a major challenge for wearable respiratory monitoring because limited sample yield often compromises analytical sensitivity and signal reliability. Herein, we report a smart bioinspired mask that enables efficient EBC harvesting through hybrid wettability engineering. Inspired by the hydrophilic–hydrophobic patterns on the Namib Desert beetle’s back and the hierarchical transport networks of leaf veins, a hybrid wettability pattern consisting of hydrophilic star-shaped domains and vein-like microchannels is constructed on a superhydrophobic substrate through a facile three-step fabrication process. This design enables coordinated droplet nucleation, coalescence, directional transport, and centralized collection of EBC. Experimental results demonstrate that this mask achieves a high EBC collection rate of 139.8 μL min–1. Integrated with a flexible electrochemical sensor array, the wearable platform further enables real-time multiplexed analysis of representative EBC biomarkers with high sensitivity and reliability. Continuous human monitoring demonstrates the capability of the system for dynamic tracking of physiological signals under real-world conditions. This work not only provides a versatile bioinspired structural design strategy for efficient regulating interfacial condensation and transport but also provides a promising platform for wearable respiratory analysis devices toward personalized health care.