Electrohydrodynamic Printed Ultramicro AgNPs Thin-Film Temperature Sensor

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 10 mu m, 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 10 mu m 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 120 x 120 mu m, with an average linewidth of less than 10 mu m, and a film thickness of less than 200 nm. The printing range of the PDMS encapsulation layer is 300 x 300 mu m, 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.

Automated summary

This study successfully demonstrated the fabrication of ultramicro thin-film temperature sensors using EHD printing, showing higher performance compared to previous methods. The potential of EHD printing to replace MEMS for achieving high-density and arrayed temperature sensing in limited space was highlighted.