Novel Flexible Packaging Enables Highly Sensitive, Self-Decoupled FBG Strain Sensing in Extreme Environments

Accurate monitoring of strain/stress of pipelines in the aerospace field is critical for design verification and fault warning. To overcome the inherent limitations in packaging and thermal stability faced by traditional Fiber Bragg Grating (FBG) sensors, an innovative flexible FBG sensor was proposed. A key feature is its specialized packaging architecture, enabling both effective strain amplification and intrinsic temperature-strain decoupling. At 500°C the sensor demonstrated outstanding operational characteristics: high stability with drift below 0.0014%, superior linearity (R2 > θ.99), and excellent repeatability with errors less than 3.44%. This work presents a viable and advanced FBG-based sensing solution for challenging high-temperature strain measurement scenarios, particularly for non-planar structures.