Measurement of physIcal properties of Gases using resoNant MEMS for chemical detectiON in hostile environments – MIGNON

We propose in the MIGNON project to achieve chemical detection without using a sensitive layer. Our proposed strategy avoids having to choose or develop a new sensitive layer for each application, depending on the species to be detected and the possible interferents.
The detection and discrimination between different gas mixtures will be based on the measurement of multiple physical properties of the gas (viscosity, mass density, acoustic wave speed and attenuation) using two kinds of resonant MEMS: microcantilevers and capacitive micromachined ultrasonic transducers (CMUTs). Then, using a combination of these two generic sensors, it will be possible to address different niche markets without specific and long development process. Moreover, the absence of sensitive coating, which is subjected to sorption or redox phenomena in classical chemical sensors, will lead to a more reliable and reversible behavior. The measurement of the gas physical properties will be done first using silicon resonant MEMS. The MIGNON project will not be focused on the transducer part, but it will rather address the complete measurement chain (sensor, instrumentation, integration and data processing). The proof of concept will be done within the project for applications which need leakage detection of industrial gases, such as O2, N2, H2, CH4, CO2 and He.
Moreover, in order to address harsh environment applications (high temperature, acid environment, radiation, …) resonant MEMS made of silicon carbide, a material known for its inertness, will also be developed. Ageing tests, such as thermal cycling, thermal storage, humidity test, mechanical vibration test on a shaker and irradiations, will be addressed for both silicon and silicon carbide MEMS in order to define their capabilities and limits in harsh environments.
The research program is divided into four scientific work-packages. WP1: Development of optimized electrostatic silicon-based sensors (microcantilevers and CMUTs). WP2: Development of silicon carbide (SiC) CMUT in order to address chemical detection in harsh environment (high temperature, corrosive chemicals and radioactivity). WP3: Development of devices integration and dedicated actuation and read-out electronics. WP4: Development of both data analysis methods to extract the gas detection information from the spectrum analysis in complex gas mixtures and ageing/reliability tests in harsh environment
To summarize, MIGNON addresses (1) the scientific and technical question of using electrostatic MEMS for the determination of multi-physics gas parameters to achieve reliable chemical detection in complex gases (not only binary mixtures) and (2) the development of compact prototypes including electronics and sensors for harsh environment. The achievement of these objectives will allow us to develop a compact generic chemical detection system based on the measurement of multi-physics gas parameters with resonant MEMS.
The achievement of the MIGNON project requires the contribution of 4 complementary partners (IMS, GREMAN, LAAS and CRHEA), covering all the scientific tasks of the project: fabrication of silicon and silicon carbide-based MEMS, electronics for instrumentation, gas test, ageing/reliability test and advanced data processing. Partners have been selected for their world-class expertise and for their ability to work together on multidisciplinary projects. MIGNON will represent a significant progress of the collaborations between IMS, LAAS, GREMAN and CRHEA.