WP2 - Objective 1 – Photonic Sensor Modules from the conception to the fabrication
Module 1: Mid-IR sensor
During the period M1-M18, CNRS-UR puts efforts to reduce absorption band in region of interest between 4 and 9µm and to minimize the rugosity of the sides of the waveguides, which could lead to a reduction of the propagation losses using Rapid Thermal Annealing (RTA) treatment. PIC based on ChG for Mid-IR applications were fabricated by CNRS-FOTON. With minimal optical losses value equal to 2.5 dB/cm. Carbon dioxide was used to demonstrate transduction in the gas phase, while acetonitrile, ethanol, isopropanol and acetic acid were used for the liquid phase. VIGO’s detectors department was carrying out the work on the prototype detectors. After a series of internal tests and measurements, the prototype modules were shipped to CNRS-FOTON and MIRSENSE. VIGO was also working on the processes based on MIRSENSE’s architecture of QCLs, to provide the epi wafers to the MIRSENSE for the next processing steps.
Module 2: Vis-NIR sensor
Active tellurite glass targets in the TeO2–ZnO–Na2O/BaO/Bi2O3 system were developed at TAU and deposited at UP into thin films using RF magnetron sputtering technique to obtain thin films that emit light in the visible and NIR confirming the presence of Er3+ ions in the network, with excellent guiding of the fundamental modes at both the pump and signal wavelengths. In the meanwhile, the designs for module 2a (Mach-Zehnder interferometer) and 2b (Young interferometer) have been realized at UEF. An initial test of the MZI has been performed with TiO2 thin film to imitate the glass film. The achieved refractive index variation measurements were as low as 10-6 RIU, which is the target.
Module 3: Optode
CNRS-LAAS worked on the development of the optode sensors, starting with the oxygen. An in-depth review of the literature guided the selection of commercial O2 sensor spots. A complete readout device for these O2 sensor spots based on lifetime sensing was designed, simulated, fabricated and characterised. The complete system was finally intercompared with a commercial reference sensor in laboratory conditions, with very promising results. The same approach is under progress for the CO2 and pH sensors.
WP3 - Objective 2 – Electrochemical Sensor Module research and development
During the period M1-M18, on the subtask 3.1.1 Au electrode size reduction from mm to µm and the subtask, in collaboration with IFREMER, CNRS-ITODYS and BRGM, KLEARIA designed and manufactured 3 iterations of electrochemical platforms. IFREMER has shown that phosphate can be detected in the micromolar range using a C/Cu working electrode. In this case, the presence of phosphate is monitored by observing the HER blocking. Phosphate can also be detected following its complexation with molybdenum in solution. Thanks to this strategy, a limit of detection (LOD) of 1.6 µmol/L is achieved.
WP4 - Objective 3 – Sensor functionalisation and Microfluidic system implementation
During the M1 -M18 period, UMONS efforts are directed towards developing HMDSO thin films to improve PDMS polymerization on chalcogenide substrates. The architecture and chemical composition of PDMS resins has been optimized for diclofenac (DF) uptake by UDE and could be suitable selective layers for the detection of hydrophilic pollutants via mid-IR sensors. O2 plasma surface treatment of ChG film, made by IFREMER prior to PDMS deposition enabled polymerization of PDMS on contact of ChG thin film. Concerning task 4.2 IFREMER was able to manufacture (using a combination of 3D printing, soft-lithography and xurography) PDMS microfluidic cells on top of various surfaces such as chalcogenide, porous silicon or polymer (such as PIB). MICROLIQUID successfully transferred the microfluidic flow cell proposed by IFREMER to rigid plastic and fabricated using 3D printing techniques. This device has then been affixed to chalcogenide surfaces and demonstrated a leak-proof flow cell system using different flow rates and kinds of commercially available pumps and values.
WP5 - Objective 4 – Integration into a portable and flexible multi-sensor device
ARGOTECH has been in cooperation with MIRSENSE and working on the HHL modules assembly and working to improve all steps to assemble the laser module (gluing processes for lasers assembly, adjusting station with high resolution camera, TEC controller for better laser cooling, clamping system for optical cables and use very precise positioning measurement system.
WP6 - Performance of the modular multi-sensor device
CNRS-UR/BRGM conducted experiments at CEDRE Laboratory to determine actual concentrations of calibration solutions of BTX ((benzene, toluene, and xylene), in order to prepare the polymer membrane functioning for non-polar analytes, with good stability of the solutions over time (5% average change in concentration after two weeks). IPHT processed electrochemical sensor data for nitrate detection, analyzed ATR-FTIR absorbance spectra to build regression models for detecting pollutants and developed a web application for data visualization and processing and conceptualized an IoT system architecture for scaling up data workflows. CNRS-UR is developing metrics for a monthly survey and plans to use OpenLCA software to assess the environmental impact of IBAIA outputs. SCIRPE investigate and find an experimental site were the probe would be tested once built with the idea to monitor Agricole non-point source pollutions (nitrates, pesticides…).
