학술논문
Amine-Functionalized Capacitive Carbon Dioxide Sensor Performance as a Function of Temperature and Sensing Film Thickness
Document Type
Periodical
Source
IEEE Sensors Journal IEEE Sensors J. Sensors Journal, IEEE. 21(13):14645-14654 Jul, 2021
Subject
Language
ISSN
1530-437X
1558-1748
2379-9153
1558-1748
2379-9153
Abstract
This paper systematically investigates sensor performance of amine-functionalized, microfabricated capacitive carbon dioxide (CO 2 ) sensors as a function of sensor temperature and sensing film thickness. The sensor comprises a 1 mm by 1 mm interdigitated electrode structure with $2~\mu \text{m}$ line width and $2~\mu \text{m}$ line spacing, surrounded by a resistive temperature sensor and a resistive heater. A mixture of 3-aminopropyltrimethoxysilane and propyltrimethoxysilane was spray-coated onto the sensors and the CO 2 response was measured in a gas mixing system. Using a 100 nm thick sensing film, a maximum sensor sensitivity of −1.2%/1,000ppm CO 2 concentration was obtained with response times of 5-10 minutes at a sensor temperature of 85°C. The sensor sensitivity decreases for higher and lower temperatures while the sensor response time monotonically decreases with increasing sensor temperature. Thicker sensing films improve sensor sensitivity at the expense of a longer response time.