An Acoustic Sensing Fabric based on PVDF-HFP Nanofiber Core-Shell Yarns for Respiratory Acoustic Signal Monitoring

Abstract

Respiratory acoustic signals provide a crucial insight for assessing respiratory system health and diagnosing related diseases. Flexible acoustic sensors hold promise for continuous, wearable monitoring but often face trade-offs between performance, comfort, and integration into daily textiles. Herein, we present an acoustic sensing fabric (ASF) woven from silver-plated nylon warps and PVDF-HFP nanofibrous core-shell wefts, which form piezoelectric/triboelectric units at yarn interlacing points to efficiently convert micro-amplitude vibrations into electrical signals. The optimized ASF exhibits high output of up to 38.3 V at 170 Hz/118 dB, and shows notable sensitivity, reaching 15 mV•Pa^-1 at 1000 Hz/94 dB and even reaching 2.5×10³ mV•Pa^-1 at 170 Hz/90-95 dB. Through systematic investigation of structural parameters, supported by laser Doppler vibrometry and finite element simulation, we elucidate how fabric structure influences forced vibration and signal output. The ASF accurately records the directly produced respiratory sounds, the playback of pathological cardiopulmonary acoustics, and daily speech, demonstrating its capability for respiratory disease diagnosis. Moreover, it can be seamlessly integrated into common textiles using standard weaving processes. This work thus provides a practical, scalable platform for designing everyday wearable systems for applications such as respiratory monitoring, remote cardiopulmonary auscultation, and voice-assisted human-machine interface.