Phd Project Title : Study And Realization Of New Sensors Dedicated To The Environment From...

Universities and Institutes of France

France

November 23, 2021

Description

  • Organisation/Company: FEMTO-ST Institute
  • Research Field: Physics › Acoustics Physics › Chemical physics Physics › Electronics Physics › Solid state physics Technology › Environmental technology
  • Researcher Profile: First Stage Researcher (R1)
  • Application Deadline: 23/11/2021 12:00 - Europe/London
  • Location: France › BESANCON
  • Type Of Contract: Temporary
  • Job Status: Full-time
  • Hours Per Week: 35
  • Offer Starting Date: 01/10/2021
  • Air pollution poses a major environmental health risk and is estimated to cause around two million premature deaths worldwide each year. Environmental monitoring requires the measurement of different species of gases and particles. It cannot therefore be carried out by a single sensor but a set of specific and selective sensors.

    Our environment is made up of many micro and nanometric particles suspended in the air that can have varying degrees of health consequences. This can result in poisoning in the case of carbon monoxide or in lung problems in the case of formaldehyde, classified as a gas carcinogenic to humans by the International Agency for Research on Cancer (IARC). Other gases, such as hydrogen, have the effect of causing explosion hazards, yet they can be of value as an energy source in many applications. Carbon dioxide is harmless to humans at low concentrations but can be emitted in very large amounts during natural combustions such as volcanic eruptions or fires. It also comes from the transport sector (fuel combustion), industry (use of fossil fuels) and housing (use of energy for heating, lighting, etc.). It is responsible for 26% of the greenhouse effect at work in our atmosphere, where the increase in its concentration is partly responsible for the global warming observed on the scale of our planet since the last decades of the twentieth century. Finally, fine particles called PM10 and PM2.5 penetrate deep into the lungs and can be the cause of inflammation and worsening of the state of health of people with heart and lung diseases. All these gases or microparticles are used or emitted in a relatively banal way on a daily basis. However, they can present a real danger to health when their concentration reaches a critical threshold.

    Elastic Surface Wave (SAW) devices are currently being investigated for the detection of low concentrations of gases or particles. Indeed, they are of high sensitivity, small in size, can be produced at low cost and have great robustness. The principle of these is based on variations in the propagation properties of surface waves from sensitive layers deposited on the sensors, depending on the amount of gas present in the environment. The phenomena of adsorption and desorption can thus be followed in a simple way by these sensors. Associated in-situ monitoring techniques are then necessary for the development of industrializable sensors.

    Description of the thesis work and integration into the general project

    The proposed subject is to study and develop surface wave sensors (Figure 1) on piezoelectric substrates with particular acoustoelectric properties in order to precisely detect toxic species present in the environment (gases and fine particles). These substrates will come from the Smart-Cut technology developed by the SOITEC company.

    - In the case of the selective detection of toxic gases, functionalization by specific organometallic layers is necessary. This will make them perform well even in the presence of interfering gases and / or humidity.

    - In the case of measuring fine particles, the nature of the latter is not important, the important criterion is their diameter; the smaller it is, the more particles will penetrate deeply into the lungs leading to respiratory pathologies.

    Currently, the sensors operate in the hundreds of hertz range but depending on the application need, in vehicle interiors in particular, they can be designed to operate in different frequency ranges up to 2.4 GHz.

    This work will be mainly carried out in the Time-Frequency department of the FEMTO-ST institute (main direction Virginie Blondeau-Patissier) in collaboration with the P2DA team of ICMUB (Dijon), specialized in porphyrins and corroles, under the management of Prof. Claude Gros and the frec n sys company directed by Dr. Sylvain Ballandras.

    More precisely, the work carried out will be shared between theory, experiments on a calibrated gas and fine particle measurement bench and numerical simulations. The project consists of developing a new generation of CO / CO2 and fine particle sensors for an automotive application based on the convergence of fundamental research and industrial motivations.

    In particular, the work program may include the following elements:

    • Study the acoustic behaviour of different POI substrates (quality coefficient, electromechanical coupling, losses, etc.), compare them with the quartz devices currently used in the team for measuring gases and particles.

    • The team has software to predict the behaviour of sensors based on their design. This will involve studying sensors with a higher operating frequency in order to reduce their size and increase their sensitivity to the species to be detected.

    • The detection of fine particles in the air required the manufacture of an impactor developed in the team (see figure 2 - Patent 2017). It is now a question of reducing its size and developing a system allowing the cleaning of the various sensors placed at the level of the floors via surface waves.

    • It will also be considered to add a new stage to the impactor in order to meet current standards on air pollution (see figure 2) and tests in outdoor conditions will be carried out.

    • Different methods of depositing layers of MOFs and COFs (organometallic molecules in the form of networks) previously synthesized by fellow chemists from ICMUB (Dijon) will be studied and their detection efficiency will then be compared according to environmental conditions (T °, Pressure) and the presence of interfering gases. The work of synthesizing these molecules is carried out in collaboration with Prof. Karl Kadish of the University of Houston.

    • Propose and perform tests in the presence of target and interfering species to quantify their selectivity and sensitivity for automotive applications. Tests in real conditions in vehicle interiors.

    • The student will benefit from the knowledge and help of the staff of the Mimento microtechnology plant for the manufacture of sensors in a clean room.

    The company Frec / n / Sys will be able to put at the service of the doctoral student its know-how and its capacities of realization of industrial components to test the molecules which it will develop within the framework of its thesis, thus providing an effective evaluation of their applicability for concrete cases of detection of molecules of interest. The complementarity of the teams in terms of research and development, associated with academic laboratories, including one in collaboration with the University of Houston, and the possibility of transferring the complete technology for the mass production of these sensors, associated with an industrial (Sté Frec / n / Sys), is an essential asset and a strong point of this project. The very strong complementarity of the 2 teams in terms of research and development is an essential asset for carrying out this work.

    Contact : Virginie Blondeau-Patissier (MCF-HDR)

    Time and frequency department – COSYMA Team

    FEMTO-ST Institute

    26, chemin de l'Épitaphe

    25 000 Besançon

    Téléphone : 03-81.40.29.58

    Mail : virginie.blondeau@femto-st.fr

    Offer Requirements
  • REQUIRED EDUCATION LEVEL
  • Physics: Master Degree or equivalent

    Skills/Qualifications

    Candidate Profile:

    Engineer and/or Research Master - Good level of general and scientific knowledge. Good level of practice of French and English. Good analytical, synthesis, innovation and communication skills. Adaptability and creativity. Motivation for research activity, in particular experimental.

    Knowledge of physic, acoustic (waves propagation). Skills and motivation for experimental research and microtechnology. Knowledge of numerical modelling in fluid mechanic, COMSOL, SOLIDWORKS will be an advantage.

    Contact Information
  • Organisation/Company: FEMTO-ST Institute
  • Department: Time & Frequency - Institute FEMTO-ST
  • Organisation Type: Public Research Institution
  • Website: https:// www. femto-st.fr/fr/Departements-de-recherche/TEMPS- FREQUENCE/Presentat...
  • E-Mail: virginie.blondeau@femto-st.fr yann.kersale@femto-st.fr
  • Country: France
  • City: BESANCON
  • Postal Code: 25000
  • Street: 26 chemin de l Epitaphe
  • Phone: +33 3 81 40 29 58
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