A team led by Prof. Kaichen Xu, Prof. Haibo Xie, and collaborators at Zhejiang University has developed a laser-based fabrication method for thin-film temperature sensors that function reliably across an exceptionally wide temperature range—from –50 °C to 950 °C—without the need for complex protective coatings.
(a) Schematic of the proposed laser-induced double-layer films compared to the conventional thermal sintering. (a-i) Schematic of the material and morphology of the film before and after laser direct writing. (a-ii) Schematic of the oxidized film caused by conventional thermal sintering. (a-iii) Schematic of the wide detection range of temperature for the proposed film-based temperature sensor. (b) Schematic of the formation process of continuous and uniform TiB2 conductive traces using laser-induced sintering. The left and center insets denote the ease of electron migration before and after laser processing, respectively. (c) Schematic of the production of an anti-oxidative glassy protective phase during laser-induced passivation. The right and center insets denote the difference in the ease of oxygen penetration before and after laser processing, respectively. Image Credit: By Yuyu Hou, Haibo Xie, Yibo Li, Zimo Cai, Bin Zhang, Yang Ju, Huayong Yang and Kaichen Xu
Published in the International Journal of Extreme Manufacturing, the research details how a precisely controlled laser pulse can directly inscribe a temperature-sensing layer onto a surface while simultaneously forming a built-in protective coating. This one-step approach could improve how temperature is monitored in high-performance equipment used in aerospace, energy, and automotive applications.
The Xu research group at ZJU is an interdisciplinary team focused on advanced manufacturing of flexible and conformal electronics for monitoring in both regular and extreme environments.
Our research mainly includes the development of innovative fabrication techniques, multifunctional devices, as well as system-level applications. Based on the principle of laser and matter interactions, we focus on manufacturing of versatile devices mainly using hybrid (ultrafast) laser processing platforms, which are endowed with multitasking features.
Kaichen Xu, Study Corresponding Author and Professor, Zhejiang University
Conventional high-temperature sensors are challenging to produce. They often require multiple material layers, lengthy sintering processes, and additional coatings to guard against heat and oxidation. In contrast, the new laser-based technique achieves all of that in a single step.
The laser briefly heats the surface, triggering crystallization that enables the material to conduct electricity and respond to temperature. Simultaneously, it forms a glass-like surface layer that naturally resists oxidation—eliminating the need for extra protective materials or fabrication steps.
The result is a sensor capable of high-accuracy, real-time temperature monitoring with long-term stability. In laboratory tests, the devices showed minimal signal drift—just 1.2 %—even after operating continuously at high temperatures for 20 hours.
Because the method is fast and material-efficient, it could streamline the integration of sensors directly into components like engine housings or gas pipelines, allowing engineers to detect early signs of overheating, stress, or failure more effectively.
The team is now working to extend the approach for measuring other physical variables such as pressure, strain, and heat flux, on the same thin-film platform. Their broader aim is to develop smart sensor systems capable of withstanding and performing in some of the most demanding environments, both on Earth and in space.
Journal Reference:
Hou, Y., et al. (2025) A laser-induced wide-range thin-film temperature sensor without additional anti-oxidative encapsulations. International Journal of Extreme Manufacturing. doi.org/10.1088/2631-7990/adefa2.