115 views | Created on 2025.01.06 | Modified on 2025.01.06 | Public Relations Team

·         Professor Ha Taejun (Department of Electronic Materials Engineering)‘s Research Team Develops a YSZ-based Capacitive Wearable Temperature Sensor

- Published in Top-Tier Journal in the Field of Compound and Alloy-Based Materials Science, Journal of Alloys and Compounds

 (IF: 5.8, Top 8.3% in JCR Ranking) -

 (Left) Kim Chaeun, Master's student, (Right) Ha Taejun, Professor

Professor Ha Taejun (Department of Electronic Materials Engineering) and his research team have developed a YSZ (yttria-stabilized zirconia)-based capacitive wearable temperature sensor by applying an optimized all-solution process. They also successfully implemented an interactive sensor capable of detecting real-time touch using body temperature.

The results of this research were published in Journal of Alloys and Compounds (IF: 5.8, Top 8.3% in JCR ranking), a leading journal in the field of materials science for compounds and alloys, under the title "Capacitive-type wearable temperature sensors based on yttria-stabilized zirconia films fabricated via microwave-assisted all-solution-process and their application for detection of touch stimuli" (Reference:https://doi.org/10.1016/j.jallcom.2024.178334).

Temperature sensors capable of real-time body temperature monitoring have garnered significant scientific interest in the field of healthcare monitoring systems. In particular, capacitive temperature sensors composed of high-dielectric constant metal oxide thin films are highly advantageous for wearable electronic devices due to their simple device structure, high thermodynamic stability, and excellent mechanical robustness. However, since the sensing performance of capacitive wearable temperature sensors is significantly affected by quasi-free carriers (QFC) depending on the crystallinity of the insulating layer, it is crucial to develop metal oxides with high dielectric constants and excellent insulating properties for use as the insulating layer. Recently, extensive research has been conducted in this area; however, the process of controlling the crystallinity of metal oxide thin films typically requires high-temperature heat treatment, which inherently limits their application and use on flexible substrates.

In response, Professor Ha Taejun (Department of Electronic Materials Engineering) and his research team developed a high-performance capacitive wearable temperature sensor based on the metal oxide YSZ using an optimized all-solution process with a low-temperature annealing technique. The fabricated capacitive temperature sensor exhibited high crystallinity based on surface potential and demonstrated a high sensitivity of 38.76 pF/°C within the temperature range of 35？50°C, which is close to body temperature. In addition, the sensor demonstrated excellent operational stability over 30 days, high response/recovery speed, low operational hysteresis, and outstanding mechanical stability under repeated bending with a curvature radius of 5 mm. Finally, leveraging the characteristics of the YSZ-based wearable temperature sensor capable of detecting temperatures within the body temperature range, the research demonstrated its potential application in healthcare monitoring systems by enabling touch detection based on body temperature.

Temperature sensing performance of the YSZ insulating layer-based capacitive temperature sensor,

analysis of the crystallinity of optimized all-solution-process YSZ thin films in flexible temperature sensor arrays, and operational stability under 5 mm bending

This research was conducted solely by Professor Ha Taejun and his research team. It is a result of the Interactive Display Research Center, where Professor Ha serves as the director, under the University Innovation Future Challenge Project. Additionally, it was supported by the Carbon Neutral Industrial Core Technology Development Project, overseen by the Ministry of Trade, Industry and Energy. Professor Ha Taejun is conducting extensive research on next-generation electronic devices, as well as sensors and energy devices, based on advanced materials. He has published over 80 papers in SCI journals and holds more than 20 international and domestic patents related to this field. In addition, first author Kim Chaeun achieved the accomplishment of publishing a paper in a top-tier international journal within the first semester of her master's program.