High‐Temperature Flexible Piezoelectric Sensors based on PZM composite Nanofiber Mats for Structural Health Monitoring in Extreme Environments

Abstract Micro‐damage detection and recognition with sensors are crucial for structural health monitoring (SHM) in extreme environments. However, traditional high‐temperature sensors are mostly restricted below 200 °C and face poor conformability; simultaneously achieving high‐temperature resistance and good flexibility remains a major challenge. Therefore, this study presents a high‐temperature flexible piezoelectric sensor based on polyacrylonitrile (PAN)/zinc acetate (Zn(Ac) 2 )/multi‐walled carbon nanotubes (MWCNT) (PZM) composite nanofiber mat via electrospinning and thermal‐treatment processes. Weakened interaction between PAN nitrile groups reduce its cyclization temperature to 259.68 °C and improves its cyclization degree to 83.33% (260 °C). The fabricated PZM sensor demonstrates an exceptional performance across a broad work temperature range (25–550 °C), high sensitivity (1.84 V/N), and high piezoelectric output (15.78 V). The PZM sensor‐based monitoring system not only demonstrates comparable monitoring capabilities to PZT sensors but also achieves damage diagnosis in complex curved structures under extreme high‐temperature environments. The PZM high‐temperature flexible piezoelectric sensor health monitoring system can accurately measure millimeter‐level damage, and long‐term operational stability and durability (5000 press‐releasing cycles repeated tapping test without performance loss at 400 °C). These demonstrations illustrate that the PZM sensor offers a versatile solution for hetero‐components health monitoring in high‐temperature environments.