A development on the wireless SAW gas sensor
Date Issued
2015
Date
2015
Author(s)
Kuo, Lu-Chung
Abstract
For the sake of human safety and industry applications, the gas detection is gradually taken seriously. CO is one of the most harmful pollutants which is colorless, odorless and tasteless. When human inhale the CO, it could cause the symptoms of headaches, dizziness and even death. Furthermore, CO is able to poison the noble metals making poor performance on the catalyst like Pt used in fuel cells. Hence, monitoring the condition of hydrogen gas is important for environmental protection and human safety. The CO SAW sensor is developed for its stability, sensitivity, convenience and low cost. In this thesis, the SAW resonator component was based on 128˚YX-LiNbO3 and the operating frequency was designed as 433MHz. The senor can operate at room temperature without a heater. It is available to combine the antenna with the SAW device to be a passive wireless SAW sensor. With mobile device, the sensor can link up with wireless system and monitor in real-time. First, the impedance load sensor and SAW resonator were designed according to the couple of mode(COM) and fabricated by MEMS technique. For higher sensitivity and better surface-area-to-volume ratio, the zinc oxide nanorod was used to be as sensing material. Furthermore, the gold particle decorated ZnO nanorod as a catalyst for strengthening the sensitivity of carbon monoxide. Second, the signal of the impedance loaded SAW sensor was analyzed in signal processing. Finally, the wireless passive sensor was completed by combining with an antenna. Besides, the sensing distance of the passive sensor could be increased by power amplify applying background reflection.
Subjects
SAW resonator
CO sensor
Au-ZnO nanorod
wireless
passive
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-104-R01543081-1.pdf
Size
23.54 KB
Format
Adobe PDF
Checksum
(MD5):0e03362d78f02889c132fb867029e75a