Electrohydrodynamic Printed Ultramicro AgNPs Thin-Film Temperature Sensor

• Published in: IEEE sensors journal Vol. 23; no. 18; pp. 21018 - 21028
• Main Authors: He, Yingping, Chen, Hongyu, Li, Lanlan, Liu, Jin, Guo, Maocheng, Su, Zhixuan, Duan, Bowen, Zhao, Yang, Sun, Daoheng, Hai, Zhenyin
• Format: Journal Article
• Language: English
• Published: New York The Institute of Electrical and Electronics Engineers, Inc. (IEEE) 15.09.2023
• Subjects: Electrohydrodynamics; Encapsulation; Error analysis; Film thickness; High density; Microelectromechanical systems; Multilayers; Performance tests; Polydimethylsiloxane; Screen printing; Sensors; Temperature measurement; Temperature sensors; Thin films
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2023.3302355

To achieve high-density and arrayed temperature sensing, thin-film temperature sensors require a multilayer structure and miniaturized preparation technology. Currently, screen printing, direct writing by squeeze, and MEMS are the main methods for preparing thin-film sensors; however, the film linewidth produced by screen printing or direct writing by squeeze is impossible to achieve width within [Formula Omitted], while MEMS is costly, and limited in terms of target materials. Electrohydrodynamic (EHD) printing is a promising alternative due to its ability to print multiple materials and multilayer structures with patterned films less than [Formula Omitted] width. In this study, we propose a method using only EHD printing to prepare ultramicro thin-film temperature sensors, including an AgNPs sensitive layer and polydimethylsiloxane (PDMS) encapsulation layer. The area of the AgNPs film sensitive layer is less than [Formula Omitted], with an average linewidth of less than [Formula Omitted], and a film thickness of less than 200 nm. The printing range of the PDMS encapsulation layer is [Formula Omitted], with a minimum film thickness of 567 nm. The performance test results show that the ultramicro AgNPs thin-film temperature sensor after EHD printing of PDMS encapsulation has a higher temperature measurement upper limit. The hysteresis error was ±0.1309%, and the repeatability error was ±0.3311%, both much lower than previously reported. The successful fabrication of ultramicro thin-film temperature sensors using EHD printing suggests the potential of this method to supercede MEMS for achieving high-density and arrayed temperature sensing in limited space.