QEPAS device capable of measurements whose quality one would normally associate with laboratory-based detection techniques such as mass spectroscopy or chromatography, but from a device well over two orders of magnitude smaller in volume;
- Capability to detect, in real time, with high precision the concentration of the targeted VOCs in the air with exceptional selectivity without the need for continuous calibration, or re-programming if an additional molecular species becomes of interest.
- autonomous nature and low-cost architecture suitable for embedded, ubiquitous pollution monitoring in an urban environment, taking advantage of the electronics cheap, embedded computers and micro-controllers.
Environmental monitoring of methane (CH4), ethane (C2H6), carbon dioxide (CO2) and water (H2O) with miniaturized QEPAS trace gas sensors composed by a common platform for the accommodation of laser source, optics and the acoustic detection module.
Calibration, validation and assessment of sensor performance: sensor responsivity, minimum detection limit and long-term stability.
Development of a computational algorithm for QEPAS sensor signal compensation for external climatic factors, namely the pressure, the temperature and the relative humidity, monitored by an electrical hygrometer installed on the QEPAS sensor.
Design, realization and test of an ultra-compact Quartz-Enhanced PhotoAcoustic spectroscopy (QEPAS) sensor employing two fiber-coupled diode laser sources and an acoustic detection module (ADM). The ADM includes a QEPAS spectrophone composed by a custom quartz tuning fork (QTF) acting as an electro-acoustic transducer, acoustically coupled with a pair of resonator tubes, to further enhance the QEPAS signal. The design of the QEPAS sensor fulfill the requirements to be installed on a drone: compact size and low-power consumption.
Design, realization and test of a miniaturized QEPAS trace gas sensor with a 3D-Printed Acoustic Detection Module (ADM). The 3D printing technique is used to realize an ADM as well as a gas cell, with reduced volumes and weight. The choice of the material was guided by performance in terms of: (i) low influence of acoustic external noise, (ii) best electro-magnetic shielding; (iii) reduction of the overall weight; and (iv) best vacuum sealing. UV-curable resin was used as the material in the 3D printing fabrication process. The target is the reduction of the weight and volume for easy accommodation on Unmanned Aerial Vehicle (UAV) systems.
Realization of fiber-coupled dual-gas QEPAS sensor employing two distributed feedback pigtailed diode lasers emitting at 1654 nm and 1684 nm, for methane and ethane detection respectively, and a single ADM. The two diode lasers are beam-combined with a custom-made solid-core fiber. The gas sensor reached a minimum detection level of 18 parts per million and 570 parts per billion at 1 s integration for ethane and methane, respectively.
Realization of fiber-coupled QEPAS sensor employing a distributed feedback pigtailed diode laser emitting at 2004 nm for carbon dioxide detection and an ADM. The gas sensor reached a minimum detection level of 20 parts per million at 1 s integration.
Publications:
Sgobba, G. Menduni , S. Dello Russo, A. Sampaolo, P. Patimisco, M. Giglio, E. Ranieri, V.M.N. Passaro, F.K. Tittel and V. Spagnolo, “Quartz-Enhanced Photoacoustic Detection of Ethane in the Near-IR Exploiting a Highly Performant Spectrophone”, Appl. Sci. 10, 2447 (2020).
Giglio, A. Zifarelli, A. Sampaolo, G. Menduni, A. Elefante, R. Blanchard, C. Pfluegl, M.F. Witinski, D. Vakhshoori, H. Wu, V.M.N. Passaro, P. Patimisco, F.K. Tittel, L. Dong, V. Spagnolo, “Broadband detection of methane and nitrous oxide using a distributed feedback quantum cascade laser array and quartz-enhanced photoacoustic sensing”, Photoacoustics 17, 100159 (2020).
Elefante, M. Giglio, A. Sampaolo, G. Menduni, P. Patimisco, V. M.N. Passaro, H. Wu, H. Rossmadl, V. Mackowiak, A. Cable, F.K. Tittel, L. Dong and V. Spagnolo, “Dual-Gas Quartz-Enhanced Photoacoustic Sensor for Simultaneous Detection of Methane/Nitrous Oxide and Water Vapor”, Anal. Chem. 91, 12866-12873 (2019).
Giglio, A. Elefante, P. Patimisco, A. Sampaolo, F. Sgobba, H. Rossmadl, V. Mackowiak, H. Wu, F.K. Tittel, L. Dong, V. Spagnolo, “Quartz-enhanced photoacoustic sensor for ethylene detection implementing optimized custom tuning fork-based spectrophone”, Optics Express 27, 4271-4280 (2019).
Sampaolo, S. Csutak, P. Patimisco, M. Giglio, G. Menduni, V. Passaro, F.K. Tittel, M. Deffenbaugh, V. Spagnolo, “Methane, ethane and propane detection using a compact quartz enhanced photoacoustic sensors and a single interband cascade laser”, Sens. Act. B Chem. 282, 952-960 (2019).