Analysis of ball surface acoustic wave sensor response to wide variety of gases using gas chromatography

It is necessary to detect a wide variety of dangerous gases for environment assessment and security. Gas chromatography using a gas separation column has been used for this purpose; however, a compact and high-performance system has not yet been established. Thus, we propose a new approach to measure gases using a ball surface acoustic wave (SAW) sensor, after separating them using gas separation columns. In this work, amplitude responses were observed for mixed alcohol gases. With water-ethanol mixed gas, both delay time and amplitude responses were observed, and different response and recovery times were found for these responses. Also, an amplitude response reflecting the leaky loss of SAW was observed and an approximate equation of leaky loss was derived to quantitatively evaluate the roles of leaky loss and other parameters observed in the ball SAW sensor. These results suggest that the proposed approach is promising for developing compact and high-performance multigas sensors.