High-performance moisture‑electric nanogenerator based on PAN/PSSA/lignin electrospun nanofibers for wearable respiratory monitoring

Moisture‑enabled electricity generation offers a sustainable route for harvesting ubiquitous atmospheric energy. In this study, a high‑performance moisture‑electric nanogenerator was developed based on blend electrospun nanofibers of polyacrylonitrile, sodium polystyrene sulfonate, and lignin (PAN/PSSA/lignin). An optimized PAN:PSSA mass ratio yielded uniform fibers with sawtooth‑like wrinkled nanostructures, which enhanced the specific surface area, moisture absorption, and ion transport. The device achieved an open‑circuit voltage of 0.85 V, a short‑circuit current of 13.52 μA, and a power density of 11.47 μW/cm 2 at 97% relative humidity (RH). The electrochemical activity of porous aluminum electrodes in humid environments enabled the formation of a stronger and longer-lasting ionic concentration gradient, yielding approximately 1.8 times voltage enhancement. The PPL‑MEG exhibited outstanding stability exceeding 100000 s at 97% RH with negligible degradation, as well as modular scalability. Five units connected in series and in parallel yielded 2.87 V and 44.25 μA, respectively. Furthermore, the device functioned as a self‑powered humidity sensor with a wide detection range of 11–97% RH and fast response. Integrated into a commercial face mask, it successfully recognized normal breathing patterns, as well as abnormal patterns such as Cheyne‑Stokes respiration and Biot’s respiration, demonstrating strong potential for wearable respiratory monitoring.