BRIC19 ID07

Integrated system of mobile and fixed sensors for the space-time dynamic mapping of volatile compounds in a working environment

Financed by: INAIL Period: July 2020 - July 2022

Introduction

The monitoring and control of the composition of the air in the workplace is an absolute priority for maintaining the well-being of the working staff and for the protection of the surrounding environment. The present project therefore aims to provide a solution to these needs and is based on the concept of cross-selective sensor arrays and on machine learning techniques for the extraction of information relating to both the quality and quantity of volatile compounds in the environment.

Description

Standard analyzes of the air composition are based on laboratory instrumentation (typically gas chromatography and mass spectrometry) characterized by high costs and the need for specialized personnel. Moreover, this instrumentation does not allow, unless at high costs, real-time measurements. Therefore, the information obtained is averaged over a long time and does not provide indications regarding releases of volatile substances that expose personnel to critical concentrations, albeit for a short time. The project aims to mimic a natural olfactory monitoring system based on chemical sensors suitably developed through the use of nanotechnologies. The technological analogue of smell consists of a matrix of partially selective sensors combined with modern data analysis techniques and Machine Learning algorithms. These algorithms are optimized to extract from the sensor array the information necessary to characterize the composition of the measured sample. The performance of this system depends on the matrix of sensors that are not selective but different from each other. This system is analogous to a system of equations with several variables, where the solution is not obtainable from a single equation but from the system. As in the system of equations, the solution of the variables can only be obtained if the equations are sufficiently different from each other, therefore it is necessary to be able to realize sensors that are quite different from each other.

Aims

The general objective of the project is the realization of an integrated system for the dynamic monitoring in time and space of volatile compounds of interest in work environments. The use of non-selective gas sensors coupled with multivariate data analysis techniques has been proposed for many years for the characterization of chemically complex environments. This project proposes an innovative use of this technology aimed at monitoring volatile compounds in a work environment providing a dynamic mapping both in time and in space. For this purpose, a network of Wireless Sensors Nodes (WSNs) will be created based on mini-arrays of sensors on flexible supports, wireless communication and suitable for being integrated into the clothes by personnel without interfering with their movements. The mobile systems will be supported by an innovative fixed system, equipped with higher performance sensors. This system is based on the integration of data from quartz microbalances and FIR spectroscopy. A further innovation concerns the unconventional use of spectroscopy which, instead of measuring VOCs in free air, will be based on the measurement of the IR spectrum in absorbent films (eg polymers) by exploiting the partition coefficient of the various volatile species. The integration of the sensors (mobile and fixed) will give rise to an innovative sensorial supra-system capable of producing localized data in time and space.

Participants

• Department of Electronic Engineering, University of Tor Vergata (Rome), UNITORV, Italy
• Department of Sciences, University of Roma Tre, Rome, UNIRM3, Italy
• DIMEILA, INAIL, Monteporzio Catone (RM), Italy
• CNR-IIA

Working group