Conformal Integration of Microfabricated Thin‐Film Thermocouples for In Situ Turbine Blade Thermal Characterization

ABSTRACT In situ monitoring of the temperature distribution on a turbine blade can enhance the real‐time evaluation of air‐cooling efficacy and facilitate the optimization of cooling channel designs. Microfabricated thin‐film thermocouples (TFTCs) provide next‐generation in situ temperature monitoring solutions for turbine designers, delivering precise temperature measurement and quick response time. However, significant challenges persist in the conformal and monolithic integration of thermocouple arrays, especially on surfaces with complex geometries and varying curvatures, like those on actual turbine blades. This study has introduced a new method for the conformal integration of thin‐film thermocouple arrays on continuously variable curvatures in a single microfabrication process, while maintaining the aerodynamic performance of the turbine blades. By using 3D‐printed shadow masks during sputtering processes, this method tackles the difficulties of conformal metal alloy thin‐film formation caused by twisted curvatures in conventional microfabrication. E‐type TFTCs are conformally microfabricated using a 3D shadow sputtering process on turbine blade test structure surfaces, forming an on‐blade in situ temperature characterization network. These microfabricated thin‐film thermocouples act as a toolbox for characterizing the temperature distribution on air‐cooled turbine blade surfaces. Furthermore, the proposed method presents a strategy for conformal microfabrication and integration of thin‐film sensors on multi‐scale complex industrial surfaces.