Integrating metal-oxide-decorated CNT networks with a CMOS readout in a gas sensor.
We have implemented a tin-oxide-decorated carbon nanotube (CNT) network gas sensor system on a single die. We have also demonstrated the deposition of metallic tin on the CNT network, its subsequent oxidation in air, and the improvement of the lifetime of the sensors. The fabricated array of CNT sensors contains 128 sensor cells for added redundancy and increased accuracy. The read-out integrated circuit (ROIC) was combined with coarse and fine time-to-digital converters to extend its resolution in a power-efficient way. The ROIC is fabricated using a 0.35 μm CMOS process, and the whole sensor system consumes 30 mA at 5 V. The sensor system was successfully tested in the detection of ammonia gas at elevated temperatures.
Department of Electrical Engineering, Seoul National University, Seoul, Korea. hyunjoong.lee@amic.snu.ac.kr
Hyunjoong
H
Lee
Sanghoon
S
Lee
Dai-Hong
DH
Kim
David
D
Perello
Young June
YJ
Park
Seong-Hyeon
SH
Hong
Minhee
M
Yun
Suhwan
S
Kim
D000641:Ammonia / Q000032:analysis; D005740:Gases / Q000032:analysis*; D008670:Metals / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D012666:Semiconductors; D013696:Temperature
D005740:Gases; D008670:Metals; D037742:Nanotubes, Carbon; D010087:Oxides; D000641:Ammonia