How does it work?
Photoacoustic sensors use medium-infrared laser sources to heat up a target gas. Miniaturized microphones then detect the characteristic sounds emitted by the induced thermal expansion. These sensors can measure the concentrations of a variety of substances such as CO2, CO, nitrogen oxides, formaldehyde or methane.
Advantages?
These miniaturized sensors are protected by more than 10 patents and can be integrated into analysis devices that are just as powerful as their laboratory counterparts all the while being lighter and more compact. This makes it easy for them to be deployed in the field.
CEA-Leti is developing silicon-based manufacturing processes that will considerably lower their cost. Notably, quantum cascade mid-infrared lasers, which are currently very expensive components, could see their price divided by 1000. This would help democratize access to these spectroscopic analysis methods.
Finally, photoacoustic sensors can be highly sensitive (down to the part-per-billion range, which is equivalent to one cubic millimeter in a cubic-meter). Certain volatile organic compounds already impact human health at such low concentrations.
Our research areas:
- Manufacturing processes for quantum cascade laser sources on silicon
- Advanced sensor integration
- Development of specific multi-gas measurements
Applications?
- Indoor and outdoor air quality monitoring
- Process and industrial discharge monitoring
- Chemical detection for security and defense
"To meet different needs in terms of performance, cost and use, we are developing four other sensor technologies: thermal conductivity sensors, non-dispersive infrared sensors, interferometric sensors and miniaturized chromatography systems.” Bertrand Bourlon, Head of CEA-Leti's Optical Sensors Laboratory