Using mixed SnO2 nanoparticles with 1 wt.% MWCNTs sensing materials, NO2, NH3, and xylene gas sensors were fabricated on micro-platforms. A micro-platform consists of micro-sensing electrode and micro-heater on 2 μm thick SiNx membrane. The fabricated gas sensors were characterized to NO2, NH3, and xylene gases, respectively, as a function of concentration at 300 °C and temperature from 180 °C to 380 °C at constant concentration. The measured highest sensitivities for the NO2, NH3, and xylene were 1.06 at 1.2 ppm and 220 °C, 0.19 at 60 ppm, and 220 °C, and 0.15 at 3.6 ppm and 220 °C, respectively. So, it was found that 220 °C was the optimum temperature to have the best sensitivities. From these results, mixed SnO2 nanoparticles with 1 wt.% MWCNTs showed good sensitivity and selectivity at low power operation below 30 mW. Fabricated micro-gas sensors could be used for ubiquitous sensor network applications to monitor environmental pollutants in the air.
Bibliographical noteFunding Information:
This work was supported by the IT R&D Program of Ministry of Knowledge Economy/Institute for Information Technology Advancement (MKE/IITA) [2006-S-078-04, Environmental Sensing and Alerting System with Nano-Wire and Nano-Tube]. We acknowledge the Korean Government for its financial support.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry