Sensors to improve combat gas detection

Thanks to the work of the NanoMIR team at the Institut d'Électronique et des Systèmes (IES, CNRS/Université de Montpellier), new solid-state optical sensors have been developed. These sensors improve the sensitivity of combat gas detection. This work opens up innovative prospects for using or refining gas detection in many fields: military, of course, but also environmental, agronomic, food and security.

The objectives and results of this work

To effectively detect the dangerous gases associated with armed conflicts, particularly nerve agents such as sarin, a collaboration between the Institut d'Électronique et des Systèmes (IES, CNRS/Université de Montpellier) and the Nanomatériaux pour les Systèmes sous sollicitations Extremes (NS3E, ISL/Université de Strasbourg) laboratory has led to the development of an optical sensor based on semiconductors (an insulating material that can be made to conduct electricity).

Infrared absorption spectroscopy is a powerful technique for identifying molecules within a sample, but it has sensitivity limitations at low concentrations. To solve this problem, Pierre Fehlen and his team have designed a new type of optical sensor, based on light/matter interactions: plasmonics. They integrated it with semiconductors operating in the mid-infrared range. Numerical simulations and analyses were carried out to design the sensor. The plasmonic sensor was then successfully tested, demonstrating its selectivity in relation to the volatile gases used.

The results of this study offer a solution to the limitations of light-matter interactions in the detection of hazardous gases. It demonstrates the effectiveness of semiconductor-based plasmonics for the detection of complex molecules by infrared absorption. The next challenge is to improve the concept by miniaturizing the device and increasing the transducer's sensitivity.