Optical Temperature Sensor Evaluation in a Working Gear Motor: Application of Luminescence Thermometry in Industrial Technology

3D printing constitutes a technological advancement, revolutionizing contemporary industry by enabling manufacturers to fabricate intricate, customized components efficiently and precisely from digital blueprints. Moreover, the fusion of 3D printing with cutting‐edge materials has given rise to compelling elements boasting a diverse range of applications. For this reason, this work describes the incorporation of a luminescent material, NaYF4, doped with Yb3+ and Er3+, embedded in resin for 3D printing to create motorized luminescent gears. The fabricated luminescent gears take advantage of the intensity ratio between the Er3+ emissions at 525 nm (2H11/2 → 4I15/2) and 550 nm (4S3/2 → 4I15/2), which are thermally coupled, to detect the slight temperature variations that gears undergo through friction. This technique can be complementary to thermovision, proving especially valuable for monitoring temperature in elements where measurement with thermographic cameras or direct contact thermometers is hampered. The findings demonstrate that optical measurements provide enhanced (statistical) precision in temperature readings compared to thermovision, with δT = 0.07 K for luminescence thermometry as opposed to δT = 0.3 K for the thermal camera. This work can inspire new research directions using 3D printing and materials with exciting properties, fostering innovative solutions in contemporary industrial technologies. The upconverting NaYF4:Yb3+‐Er3+ particles excited with 975 nm NIR laser are used as a remote optical temperature sensor. They are mixed with resin to 3D‐print and fabricate gears and determine the temperature that is reached due to the friction between the teeth in the gears, in a working gear motor. The results from luminescence thermometry are finally compared with thermovision.