Access Type
Open Access Embargo
Date of Award
January 2023
Degree Type
Dissertation
Degree Name
Ph.D.
Department
Electrical and Computer Engineering
First Advisor
Yong Xu
Abstract
This dissertation introduces the development of 3 type of gas sensors for different applications.Chapter 2 reports a simple but effective methane sensor based on off-the-shelf quartz tuning forks (QTFs). It has been experimentally demonstrated that the presence of methane increases the resonant frequency of a single QTF with a sensitivity of 0.0063 Hz/1% or 0.19 ppm/1% and a detection limit of 0.025% at 0.5 Hz sampling rate. For the differential device with 2 QTFs, the values reach to 0.0050 Hz/1% and <0.0386% at 0.25 Hz sampling rate. An excellent selectivity to carbon dioxide, which causes a decrease of the resonant frequency, has been illustrated. Temperature, pressure and humidity responses have been characterized. This new methane sensor is expected to meet the requirements of cost, power, size, reliability and explosion permissibility for coal mine safety applications. Chapter 3 illustrates an in-situ soil probe prototype development for Arctic area underground greenhouse monitoring utilizing commercially available CO2 sensors. Several single and double measurement site prototypes indoor and outdoor test results show the reliability and robustness. These prototypes are ready for real field test to provide long-term Arctic soil information in harsh environments. Chapter 4 uses a simple, surfactant-free solvothermal method to synthesize spherical Pt−Ni NPs which was coated onto a planar electrochemical sensor device as the electrode material. With BmpyNTf2 as the electrolyte, O2 and H2 sensing reaction were investigated. The sensor exhibited a high sensitivity to O2 ((3.04 ± 0.18) × 10−5 mA cm−2 ppm−1) compared to commercial Pt/C-based sensor ((2.57 ± 0.22) × 10−5 mA cm−2 ppm−1), and H2 sensitivity for (0.331 ± 0.014) × 10−4 mA cm−2 ppm−1. Other feature such as rapid gas response, high selectivity and superior reproducibility were also demonstrated.
Recommended Citation
Chen, Xiaoyu, "Gas Sensor Development For Environmental And Soil Monitoring" (2023). Wayne State University Dissertations. 3902.
https://digitalcommons.wayne.edu/oa_dissertations/3902