Laser micro-fabricated multifunctional sensing layer for structural health monitoring

Multifunctional sensing layer (MSL) integrated with multiple sensors and transducers has diverse applications in structural health monitoring (SHM). However, current MSLs still suffer from using rigid sensing units and complicated fabrication methods. To address this, a type of MSL integrated with flexible multi-functional sensing units and stretchable interconnectors was developed in this study by a laser-microfabrication (LMF) method with high efficiency and scalability. The flexible strain sensor has a sensitivity of 8.5, a minimum detection limit of 0.01%, and a durability of up to 12 000 cycles. The flexible temperature sensor has a temperature coefficient of resistance up to 2.75 × 10⁻³ °C^–1 and a response time of 2.5 s. The flexible comb transducer provides a damage detection accuracy of over 90%. Further investigation proves the capability of the MSL for real-time monitoring of pressure vessels. The high efficiency and scalability of the LMF as well as the multi-functional sensing ability pave the potential application of the MSL in SHM.