Micro Gas Preconcentrator Made of a Film of Single-Walled Carbon Nanotubes

Abstract

The development of micro gas preconcentrators is crucial for the realization of miniaturized gas chromatography (micro-GC) systems which are expected to open up new applications such as breath analysis. One of the major problems with the reduction in the preconcentrator size by miniaturization is the availability of a sorbent material having high enough concentration factor. Single-walled carbon nanotubes (SWNTs) are one of the promising materials for high adsorption capacity. In this report, a gas preconcentrator having a depth of 40 μm and a volume of 1 μL was microfabricated. The synthesized SWNT films with a thickness of 30 μm were embedded in the micro gas preconcentrators by using the hot water-assisted detachment method. The small size of the fabricated micro gas preconcentrator and the use of SWNTs as the adsorbent material allow for achieving a concentration factor as high as 16000 for 2 ppm octane. This concentration factor value is the highest reported to date for micro gas preconcentrators and sufficient for micro-GC detectors to concentrate trace analytes of interest for breath analysis. It is concluded that micro gas preconcentrators using SWNTs as the adsorbent material have great potential to concentrate compounds.