Progress in research on surface acoustic wave gas sensors and system environmental adaptability

[ Instrument network instrument research and development ] Surface acoustic wave has the unique advantages of fast, high sensitivity, miniature, and light weight in gas sensing applications, so it has great application prospects in the fields of individual defense, public safety and industrial process monitoring.

The Wang Wen team of the Institute of Acoustics of the Chinese Academy of Sciences and the Pan Yong team of the Institute of Chemical Defense of the Academy of Military Sciences, based on long-term research on the mechanism of surface acoustic wave gas sensing and device optimization, have carried out acoustic Research on the environmental adaptability of surface wave gas sensors and systems. Related results have been published in Sensors and Actuators B and RSC Advances.

In addition, the surface acoustic wave gas sensor involves three aspects: chemical interface film, saw sensor and electronic circuit. In the application, in order to eliminate the influence of environmental temperature, pressure, humidity and other factors on the measurement results, a dual-channel structure is usually used. One channel is coated with a sensitive film for measurement, and the other is an uncoated reference channel for the ambient temperature. For compensation of factors such as pressure, humidity, etc., the frequency difference between the two can be obtained through calculation, and the concentration of the gas to be measured can be obtained.

Researchers through the synthesis of hexafluoroisopropanol polysiloxane (fluoroalcoholpolysiloxane, SXFA) and polyepichlorohydrin (polyepichlorohydrin, PECH) synthesis and thin film preparation methods and surface acoustic wave device optimization research, designed and developed for phosphine-containing High-performance surface acoustic wave gas sensors for rapid detection of sulfur-containing toxic gases, and experimental research on their environmental adaptability. The test results show that the lower detection limit of the sensor for dimethyl methyl phosphonate (DMMP) and 2-chloroethyl ethyl sulfide (CEES) can reach 0.12mg/m3 and 1.5mg/m3; It has a reliable ability to adapt to a wide temperature and high humidity environment; the smoke that troubles most gas-sensing technologies does not have a significant impact on the sensor.

Studies have shown that surface acoustic wave gas sensing technology can provide a good solution for the rapid and highly sensitive monitoring and early warning of toxic gases in complex application environments. The research work is funded by the National Natural Science Foundation of China.