Ultra-lightweight aerogel-fibrous material with high thermal stability and boosted triboelectricity for crack detection in harsh environments

Effective structural health monitoring (SHM) in harsh environments requires sensing platforms capable of reliable operation under moisture, elevated temperatures, and mechanical stress. Here, we report a crack-detecting triboelectric nanogenerator (CD-TENG) designed for autonomous sensing under extreme thermal and wet conditions. The device incorporates a nanostructured aerogel composed of polyimide (PI) and poly(vinylidene fluoride–trifluoroethylene) (P(VDF-TrFE)), providing high thermal stability and enhanced charge trapping, together with a fibrous polyvinylidene fluoride (PVDF) top layer to improve hydrophobicity and triboelectric performance. The PVDF layer exhibits an advancing water contact angle of 127° and a receding angle of 86°, enabling efficient droplet motion and liquid–solid contact electrification. Surface cracks are detected through alternating current (AC) signals generated as water droplets traverse the inclined TENG surface and interact with crack sites. A single droplet falling from 30 cm onto a 70° inclined surface generated an output of 7.9 V and 0.79 μA. Under optimized conditions (15 cm droplet height, 50° substrate slope, and 20 MΩ load), the CD-TENG achieved a peak power density of 33 mW·m -2 . These results demonstrate the potential of CD-TENGs as lightweight, self-powered sensors for real-time crack detection in harsh environments. • Self-powered triboelectric nanogenerator for real-time crack detection • Hierarchical aerogel–fibrous architecture based on PI/P(VDF-TrFE) and PVDF • High thermal stability and moisture resistance for harsh environments • Peak power density of 33 mW.m -2 under dynamic droplet impact • Demonstrated crack monitoring for aerospace, marine, and automotive structures