To perform reliable analyses of real-world gas samples, a very high selectivity is necessary to avoid false signals provided by interferents in the complex sample matrix. In most cases, especially for chemical analyses, a single sensor response is not sufficient to precisely quantify the target analyte.

Multifunctional sensing systems based on microsystems integration, often exploiting nanomaterials/nanosystems at the sensing interface, allow for acquiring, processing and evaluating multiple signals on different domains. As an example, chromatographic techniques separate complex mixtures in the time-domain, while different sensing principles (MOX sensor, photoionziation detectors, thermal conductivity detectors) can detect and quantify the target gases through different chemical and/or physical interactions. The combination of different technologies, including sample pre-separation and conditioning, and use of multiple sensing principles, allows for a great enhancement of the sensing system selectivity, enabling the use in real-world application scenarios.

Smart Systems Integration of micromachined devices with custom acquisition and signal processing electronics allows for extreme miniaturization of complex analytical sensing chains, similar to those which are usually found as bench-top instrumentation in analytical laboratories. Furthermore, most physical and chemical sensing mechanisms scale favorably into the micro- or nano-domain, therefore miniaturized analytical devices generally provide higher sensitivity, shorted analysis times and lower consumption of electrical power and consumables/reagents.

IMM-Bologna develops advanced analytical multi-sensing systems, and all the core components are developed as MEMS-based devices: gas and/or liquid injectors, fast pre-concentrators, packed and capillary gas chromatographic separation columns, and miniaturized or micromachined detectors. The microfluidic devices are based on silicon and silicon/pyrex multi-wafer assemblies, integrating multisensing capabilities (e.g. integrated heating and temperature sensing). These devices are currently integrated at system level, including custom electronics, firmware and software. Future development activities target package-level integration of an all-in-silicon gas-chromatographic system, and development of new analytical microdevices and detectors.

Applications include environmental analyses, safety&security, agrofood, energy (natural gas analyses) and industrial applications. Miniaturized and portable multisensing systems exploiting gas-chromatographic separation for in-field analyses are prototyped up to TRL6, and technological transfer to national SMEs is in progress.

Contact person: Stefano Zampolli