MST enabled gas-chromatography and spectroscopy for Security, Industry, Health and Environment: state-of-the art, trends and perspectives

摘要

Smart sensing systems based on MicroSystems Technologies (MST) are expected to have an important economic impact, especially when miniaturized low-cost devices with increased performance and high reliability will be available. A good analytical performance and a high quality of the acquired data is mandatory for special applications like security, safety, industrial monitoring and medical analyses, while transportability, low power consumption, automatic operation and smart signal processing are required for integration in autonomous sensor networks. A major issue in reliable gas analyses is the interference typically occurring in complex mixtures, where an incomplete selectivity of the sensing devices can result in false positives or in missing detections of the target analyte. As an example, many sensing technologies suffer from interferences caused by changes in the relative humidity of the sample, since water vapour is generally present in most gaseous realworld samples. In analytical chemistry, several techniques were developed to perform selective analyses by means of sample treatment and/or separation techniques. Gas-chromatography (GC) and mass spectroscopy are widely established techniques for laboratory analyses of very complex samples, allowing to reliably perform quantitative measurements, although well-trained personnel is generally necessary. MST have been successfully proposed for the miniaturization of chromatographic techniques for several decades, while mass spectroscopy requires high vacuum operation and complex pumping systems. On the other hand, ion mobility spectroscopy (IMS) can be performed at atmospheric pressure and scales well into the micro-domain, which has led to several interesting developments during the last decade. For the study, design and development of micromachined analytical systems a multidisciplinary knowledge in chemistry, physics, engineering, signal processing and system engineering is mandatory, together with a good understanding of market issues and user needs.