Material-integrated composite humidity sensors for condition monitoring of fiber-reinforced plastics

Penetrating water in fiber-reinforced plastics can alter the mechanical properties considerably. To avoid potential resulting failure of the component, we propose continuous monitoring of the humidity inside the material by highly-sensitive humidity sensors based on nano- or microcomposites. Here we report on the inline-capable fabrication and integration of humidity sensors in glass fiber-reinforced polyamide (GF-PA6). Mean water concentrations of less than 0.5 wt. % have been clearly determined inside the laminate.