Smart Masks for in situ Exhaled Breath Condensate Harvesting and Analysis

Citation

Heng, Wenzheng (2025) Smart Masks for in situ Exhaled Breath Condensate Harvesting and Analysis. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/7kzx-ee44. https://resolver.caltech.edu/CaltechTHESIS:03172025-234845488

Abstract

With the growing focus on personalized breath health management and early detection of chronic pulmonary diseases, there is an urgent demand for noninvasive wearable technologies capable of continuous breath molecular monitoring during daily activities. Existing respiratory monitoring systems remain limited to physical signal tracking and lack the capability for real-time biochemical analysis of exhaled biomarkers. To address this critical gap, we developed EBCare, a fully integrated smart mask platform for automated in situ analysis of exhaled breath condensate (EBC) biomarkers. The system combines tandem passive cooling strategies (hydrogel evaporation and radiative metamaterials) with bioinspired microfluidics to enable sustainable breath condensation and efficient sample transport under real-world conditions. A multiplexed electrochemical sensor array functionalized with nanoengineered interfaces achieves selective detection of key inflammatory markers (nitrite, pH) and metabolic indicators (ammonia, alcohol), while an embedded wireless module facilitates continuous data transmission. System validation through controlled breathing experiments and field trials demonstrates reliable operation across diverse environments (10-35°C, 30-80% humidity). Clinical evaluations involving healthy subjects, COPD/asthma patients, and post-COVID cohorts reveal EBCare's ability to dynamically track airway inflammation patterns and metabolic shifts during daily tasks. This wearable EBC analysis platform bridges the gap between laboratory-based breath testing and real-world respiratory monitoring, offering a scalable solution for home-based management of chronic respiratory conditions and post-infection recovery tracking. The modular design and automated operation framework further support future expansion to monitor airborne pathogens and systemic metabolic disease biomarkers through exhaled breath.

Thesis Files