Bioinspired Interfacial Stabilization for Ultrahigh‐Temperature Wide‐Range Conformal Thin‐Film Strain Sensors

ABSTRACT Conformal thin‐film sensors enable in situ monitoring of harsh service environments in hot‐section components. Nevertheless, rapid oxidation and structural degradation at ultrahigh temperatures significantly restrict their long‐term stability and reliability. Inspired by the layered protection–support–function organization of cactus tissues, we design a bioinspired multilayer thin‐film strain sensor for sustained operation under ultrahigh‐temperature conditions. The sensor is composed of a top glass–glaze layer, an intermediate HfO 2 /SiCN composite microgrid, and an underlying platinum resistive sensing layer. During operation at 1300°C–1500°C, the glass–glaze layer limits oxygen ingress, while the HfO 2 /SiCN microgrid provides structural confinement and interfacial support for the Pt sensing network, collectively suppressing thermally accelerated oxidation and microstructural degradation. As a result, the sensor achieves a low resistance drift rate of 0.15%/h during long‐term operation at 1500°C. Stable and repeatable strain responses are maintained at 1500°C under 370 µε, and large‐strain sensing up to 6400 µε is further demonstrated on Ni‐based superalloy substrates. This work establishes a bioinspired multilayer functional‐material architecture for stabilizing Pt thin‐film sensors in ultrahigh‐temperature oxidizing environments, providing a viable route toward reliable in situ sensing for extreme‐environment systems.