In-situ damage self-monitoring of fiber-reinforced composite by integrating self-powered ZnO nanowires decorated carbon fabric

The tradeoff between damage self-sensing abilities and mechanical properties of composites is still a challenge for incorporating functional materials as potential sensing components. In this work, multifunctional carbon fabric coated with piezoelectric zinc oxide nanowires (ZnO NWs) was integrated into a carbon fiber reinforced composite as simultaneously a self-powered damage sensing component and mechanical reinforcement. The embedded ZnO NWs endowed the composite with in-situ self-sensing of damage. The sensing characteristics corresponding to the composite damage were validated by a well-established acoustic emission method. The results showed comparable performances to those obtained by common damage detection techniques. Additionally, the introduction of ZnO NWs had a positive impact on the mechanical properties of the host composite, increasing tensile and flexural strengths by 7.4% and 4.8%, respectively. These values were significantly higher than those of the interleaved strong piezoelectric PVDF thin films, leading to severe degradation in both tensile strength (−28.6%) and flexural strength (−82.4%). The enhanced mechanical properties may be ascribed to the interfacial mechanical interlocking and the increased bond area induced by the penetration of stiff ZnO NWs into the resin matrix. Overall, the excellent online and in-situ damage self-monitoring abilities with inherent structural benefits make ZnO NWs-based sensing scheme promising for broad applications in the field of structural health monitoring.