Mask‐Integrated Triboelectric Nanogenerator With Electrical Discharge Output and Sustained Wearability via Ultralight Silver‐Coated Balls

ABSTRACT Human breathing generates continuous low‐frequency airflow in daily life, which can serve as a naturally available mechanical energy source for wearable energy harvesting without requiring additional user action. Breathing‐driven airflow has attracted attention as an input source for mask‐integrated self‐powered wearable systems. However, breathing‐induced airflow is typically low in intensity (3–6 m/s) and frequency (12–20 breaths/min). Even small structural additions to mask‐based wearables can increase their weight and volume, thereby reducing their wearability. To address these challenges, we developed a mask‐integrated ultralight triboelectric nanogenerator with silver‐coated balls and a discharge‐based power‐generation structure. By coating the expanded polystyrene balls with silver paste, the device maintained metal‐to‐metal contact while minimizing weight. Under breathing‐driven operation, the optimized device produced 22.4 V and 12.8 mA and remained electrically stable over 1 million operating cycles. These results indicate its potential as a compact, lightweight, and comfortable energy harvester for breathing‐based wearable devices.