Development of Portable Gas Chromatograph Using Ball Surface Acoustic Wave Sensor for Measurement of Crewed Space Environment

A gas chromatograph (GC) is effective as one of the methods for monitoring the atmosphere in a crewed space environment. However, the GC is generally large and difficult to carry. We have developed portable GC systems with a ball surface acoustic wave (SAW) sensor; ball SAW GC. The key features of the ball SAW GC are multiple roundtrips of SAW on a spherical element and a metal micro-electro-mechanical-systems (MEMS) column formed by etching and diffusion bonding of stainless-steel plates. In addition, using the feature of ball SAW sensor that can detect gases non-destructively, we have developed a forward flush method realizing fast analysis of multiple gases by combining two columns and two sensors. In this study, we developed a prototype ball SAW GC applied the forward flush method with the volume of 1 L and which has the same functions as a desktop GC such as a sampler, a preconcentrator, and a column heater. Using this GC, we succeeded in analyzing multiple hazardous gases assumed in the crewed space environment.