POST-DOC POSITION 2025 - Interface functionalization for improving the reliability of onboard piezoresistive sensors (Acronym : FIABLE)

Keywords: adhesive, elastomer, oil, thermo-oxidation, visco-hyperelasticity, sustainability 

Dates: 24 Months: February/March 2025 - January/February 2027 

Location: University of Technology Tarbes Occitanie Pyrénées (FRANCE) – National School of Engineering in Tarbes (ENIT) – Production Engineering Laboratory (LGP) – Mechanics-Materials-Processes Department 

Salary: gross annual salary 35000 € 

Context

The objective is to develop a new generation of sensors incorporating piezoresistive cells that can withstand a high temperature range of -55°C to 200°C, without reducing the stability of the signal during the pressure transmission. The research subject concerns the identification of physico-chemical challenges for a relevant choice of polymer materials used as components and assembly solutions to avoid any instabilities in the sensor output signal in this severe and confined environment. 

Scientific issues and methodology 

Two material grades are of interest to this research project: (A) the adhesive polymer ensuring the assembly between the piezoresistive element and the support (base); (B) the encapsulating resin for the transmission of pressure from the metal membrane to the piezoresistive element. For the first material family, based on specifications, commercial adhesives will be studied. An experimental plan will: (i) identification of rheological and thermal behaviors during adhesively bonding assembly, (ii) study of the adhesion and adherence of adhesive joint, (iii) the sustainability of the joint under thermal stress. Custom formulations will be proposed to compensate for the shortcomings of commercial solutions.

In parallel, from specifications based on functional properties but also implementation constraints, several commercial encapsulation materials will be studied. The first characterizations will focus on the thermal stability of materials under thermal stress and the evolution of material parameters, in particular the compressibility rate and thermal expansion. Then the pressure transmission from the encapsulant to the sensor under thermal stress will be quantified experimentally by modeling in the case of a simplified design. Analytical, semi-analytical or even finite element resolution schemes can be defined based on experimental behaviors. 

Requirements 

We are looking for a highly motivated candidate with solid knowledges of Materials Science, particularly polymers and specific skills in experimental testing. Knowledge of Materials Mechanics would be a plus. Adaptability, an inquisitive mind, enthusiasm for exploring new directions and the ability to provide practical solutions will be essential qualities. Good presentation skills and a willingness to publish and promote your research are essential.

The post is available for 24 months from: February/March 2025.

Applicants must provide CV, covering letter, PhD thesis and reviewers reports to valerie.nassiet@uttop.fr, bouchra.hassoune-rhabbour@uttop.fr

Host establishment

This work will be carried out at the laboratory LGP (Laboratory of Engineering Production) that is housed at the University of Technology in Tarbes UTTOP - National School of Engineering in Tarbes, located in the South-West of France. The LGP has had a strong track record since its early days and has been recognised by the French Ministry of Higher Education and Research since 1991. The vision of the LGP is the achievement of excellence across the production process, through a multidisciplinary approach in the field of material science, mechanical engineering and systems engineering. Precisely, this work will be supervised by senior researchers working in the field of solid materials mechanics and materials sciences.