Photoacoustic MEMS resonant gas sensor

C2N, CNRS-Université Paris-Saclay; France; Sur place; EUR 40 000 - 60 000; Plein temps

Résumé du poste

A research institution in France is offering a PhD position focused on developing a compact, ultra-sensitive, and selective photoacoustic gas sensor. Candidates should possess a Master's degree or be nearing graduation and have a keen interest in multidisciplinary fields like mechanics, electronics, and optics. Skills in optics, analytical modeling, and programming in Matlab or Python are an asset. Funding is available, and early start conditions are negotiable with internships possibly starting in March or April 2026.

Prestations

Funding available

Opportunity for internship starting in 2026

Qualifications

• Master's degree or students due to graduate in relevant research fields.
• Willingness to work in cleanroom conditions.
• Interest in multidisciplinary fields including mechanics, electronics, optics.

Responsabilités

• Develop a compact, ultra‑sensitive, and selective photoacoustic gas sensor.
• Perform analytical modeling and finite element analysis.
• Fabricate and characterize devices in cleanroom conditions.

Connaissances

Optical metrology

Vacuum testing

Analytical modeling

Finite element analysis

Matlab

Python

Acoustic phenomena

Formation

Master's degree in relevant field

Outils

Signal generators

Oscilloscopes

Micro/nanoscale characterization tools

Description du poste

Offer Description

Chronic respiratory diseases are among the most common noncommunicable illnesses worldwide, largely due to harmful environmental, occupational, and lifestyle exposures [James2017]. In 2017, the European Respiratory Society (ERS) defined research priorities in breath biomarkers [Horvath2017], recommending technologies for selective recognition of gases and standardized real‑time procedures to assess pulmonary function. Currently, only a few electrochemical sensors exist for exhaled breath. They are sensitive but poorly selective, detecting only limited gases. In hospitals, nitric oxide (NO) is the sole breath biomarker used in pulmonary disease diagnosis. CO₂, CO, and O₂ are occasionally measured in high concentrations under specific protocols to evaluate mechanisms such as alveolar diffusion. Except for capnography (CO₂), no equipment provides real‑time measurements across respiratory zones like trachea or alveoli.

This thesis aims to develop a compact, ultra‑sensitive, and selective photoacoustic gas sensor. Photoacoustic spectroscopy (PAS) detects gases by measuring their absorption lines. A laser tuned to the target gas wavelength produces local heating and pressure variations, recorded by an acoustic detector (microphone, cantilever, quartz tuning fork, or MEMS). Detection is independent of optical wavelength and path length, enabling work on very small gas volumes and rapid detection. The proposed structure employs a resonant strain gauge, whose frequency shifts with membrane deformation under acoustic excitation.

Funding is already available and the PhD may start as soon as the adequate candidate is found and selected. Starting with an internship starting in March or April 2026 is also possible for candidates who are still Master students at the time of application.

Funding category: Autre financement public

ANR

PHD title: Doctorat en sciences de l'ingénieur

PHD Country: France

This multidisciplinary project involves several fields, including:

Multidisciplinary Fields

• Mechanics: linear and nonlinear resonators, solid understanding of acoustic phenomena and structural vibrations, analytical modeling and finite element analysis.
• Electronics: test benches including signal generators, synchronous detection, phase‑locked loops, oscilloscopes, computer interfacing, etc.
• Optics: even though most of the work is not dedicated to optics, understanding the principles behind the photoacoustic phenomenon is essential. The candidate should also be motivated to improve his/her skills in optical metrology at the micro/nanoscale.
• Cleanroom fabrication processes: willingness to work on the fabrication and characterization of devices in cleanroom conditions, including lithography, etching, microscopy observations, and optical characterization of moving nanostructures.

It is of course not required that the candidate be fully proficient in all these areas, but she/he should be motivated to explore them. Skills in optics (particularly experimental know‑how) and experience with vacuum testing would be considered an asset. Knowledge of Matlab and/or Python would also be a plus.