Advances in nanogenerator enabled smart mask-based self-powered health monitoring units

Abstract

The detection and analysis of volatile biomarkers in exhaled breath have emerged as promising non-invasive strategies for early disease diagnosis, therapeutic monitoring, and personalized healthcare. Traditional gas sensing platforms, however, often face limitations including dependency on external power sources, bulky designs, and inadequate sensitivity or selectivity under physiological conditions. This work provides a complete overview of recent improvements in self-powered gas sensors, with a special emphasis on their use in exhaled breath analysis for health monitoring. We begin by discussing the biomedical importance of breath-based diagnostics and the significant challenges associated with traditional sensor technology. Afterward, we investigate the mechanisms of energy harvesting systems such as triboelectric nanogenerators (TENGs) and piezoelectric nanogenerators (PENGs), which facilitate the self-powered operation without an external energy supply. Innovations in materials, structural design techniques, and integration strategies that improve mechanical flexibility, sensitivity, and gas selectivity are highlighted. We also highlight recent breakthroughs in wearable and portable gas sensing platforms that demonstrate real-time responsiveness and human-interfaced compatibility. Despite significant progress, challenges such as miniaturization, biomarker specificity, signal stability in dynamic environments, and large-scale manufacturability still need to be addressed. Finally, we discuss potential ways to address these barriers, envisioning a future where selfpowered gas sensors play a transformative role in point-of-care diagnostics, continuous health monitoring, and smart healthcare ecosystems. This review aims to serve as a valuable resource for researchers and developers seeking to advance the field of self-powered biomedical sensing technologies.