Application of 3-D Printing and Upconversion to Optical Temperature Sensors

A functional optical thermal sensor has been fabricated by coating the internal surfaces of a hollow tube, produced through 3D printing technology, with a composite of resin and fluoroindate glass doped with erbium and ytterbium. The active material’s response to temperature changes was initially calibrated using the luminescent intensity ratio (LIR) technique. Subsequently, the tube’s temperature was estimated while filled with a flowing liquid by analyzing the upconversion emission spectra of the tube, again using the LIR technique. The relative sensitivity and temperature uncertainty, essential for the comparison with other luminescence-based optical thermal sensors, were obtained. The results of this study demonstrate that the tube fabricated with 3D printing technology is effective as an optical thermal sensor and offers a wide array of potential industrial applications.