A Wearable Thermoelectric Respiratory Sensing System for Quantitative Pulmonary Function Monitoring

The dynamic management of chronic obstructive pulmonary disease (COPD) and related obstructive airway diseases, such as asthma, demands respiratory monitoring technologies that combine high spatiotemporal resolution, long-term stability, and broad applicability. Yet current approaches, including bulky clinical systems, thoracoabdominal strain sensors prone to motion artifacts, and hydrogel-based airflow sensors susceptible to drift from solvent evaporation, fall short of these requirements in terms of portability, robustness against interference, and durability. Here, we report a porous graphene-based foam sensor that decouples strain-temperature to achieve simultaneous, crosstalk-free detection of deformation and airflow temperature without complex signal processing. The foam sensor maintains high mechanical and thermoelectric stability after 15,000 cyclic compression at 80% strain. Using the produced thermoelectric signal, we define a novel small airway obstruction index (SAOI) that provides individualized early warning of COPD acute exacerbation risk, enabling timely, real-time adjustment of treatment regimens.