Integrated Temperature and Hydrogen Sensors with MEMS Technology

Hongchuan Jiang; Min Huang; Yibing Yu; Xiaoyu Tian; Xiaohui Zhao; Wanli Zhang; Jianfeng Zhang; Yifan Huang; Kun Yu

doi:10.3390/s18010094

Integrated Temperature and Hydrogen Sensors with MEMS Technology

Sensors (Basel). 2017 Dec 31;18(1):94. doi: 10.3390/s18010094.

Authors

Hongchuan Jiang¹, Min Huang², Yibing Yu³, Xiaoyu Tian⁴, Xiaohui Zhao⁵, Wanli Zhang⁶, Jianfeng Zhang⁷, Yifan Huang⁸, Kun Yu⁹

Affiliations

¹ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. hcjiang@uestc.edu.cn.
² State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. hmpine@hotmail.com.
³ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. 201621030517@std.uestc.edu.cn.
⁴ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. 201621030515@std.uestc.edu.cn.
⁵ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. xhzhao@uestc.edu.cn.
⁶ State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. wlzhang@uestc.edu.cn.
⁷ National Key Laboratory of Science and Technology on Vacuum Technology and Physics, Lanzhou Institute of Physics, Lanzhou 730000, China. zhangjianfeng510@spacechina.com.
⁸ National Key Laboratory of Science and Technology on Vacuum Technology and Physics, Lanzhou Institute of Physics, Lanzhou 730000, China. huangyifan@spacechina.com.
⁹ Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621000, China. yukun@caep.cn.

Abstract

In this work, a PdNi thin film hydrogen gas sensor with integrated Pt thin film temperature sensor was designed and fabricated using the micro-electro-mechanical system (MEMS) process. The integrated sensors consist of two resistors: the former, based on Pt film, is used as a temperature sensor, while the latter had the function of hydrogen sensing and is based on PdNi alloy film. The temperature coefficient of resistance (TCR) in both devices was measured and the output response of the PdNi film hydrogen sensor was calibrated based on the temperature acquired by the Pt temperature sensor. The SiN layer was deposited on top of Pt film to inhibit the hydrogen diffusion and reduce consequent disturbance on temperature measurement. The TCR of the PdNi film and the Pt film was about 0.00122/K and 0.00217/K, respectively. The performances of the PdNi film hydrogen sensor were investigated with hydrogen concentrations from 0.3% to 3% on different temperatures from 294.7 to 302.2 K. With the measured temperature of the Pt resistor and the TCR of the PdNi film, the impact of the temperature on the performances of the PdNi film hydrogen sensor was reduced. The output response, response time and recovery time of the PdNi film hydrogen sensors under the hydrogen concentration of 0.5%, 1.0%, 1.5% and 2.0% were measured at 313 K. The output response of the PdNi thin film hydrogen sensors increased with increasing hydrogen concentration while the response time and recovery time decreased. A cycling test between pure nitrogen and 3% hydrogen concentration was performed at 313 K and PdNi thin film hydrogen sensor demonstrated great repeatability in the cycling test.

Keywords: MEMS; PdNi thin film; TCR; hydrogen gas sensor.