Description du sujet de thèse

The French industry includes several sectors of excellence in the fields of aerospace and defense: naval vessels, aircraft, satellites, missiles. In these sectors, value chains require the availability of MEMS (Micro-Electro-Mechanical Systems) components whose performance is far superior to that of consumer-grade components. Transferring these high-performance components to aeronautical applications currently reveals a major obstacle: their ability to withstand harsh environments, including resistance to vibrations and shocks.
One of the techniques considered to reduce this limitation is the insertion of an interposer incorporating phononic crystals between the sensitive element and the environment. Phononic crystals are assemblies of periodic materials that make it possible to manipulate mechanical waves in new ways, notably by creating frequency band gaps that prevent mechanical waves from propagating through structures.
The objective of the PhD is to develop a phononic crystal that will be used to create an interposer for isolating a resonant MEMS and/or protecting it from vibrational environments. The interposer will include a network of structures acting as attenuators or reflectors to either limit external vibrations from interfering with the MEMS, or concentrate the MEMS vibration on the resonant system in order to improve its quality factor.
The PhD work will focus on:
Studying a phononic crystal adapted to a MEMS developed at ONERA (gyroscope or time base) using finite-element simulations.
Developing fabrication processes as well as manufacturing demonstrators in a clean room.
Fully integrating the interposer into a package with ONERA's MEMS sensors to produce a first complete demonstrator.
This PhD project is part of an ASIC agency program dedicated to developing packaging technologies for harsh environments.

Required qualifications:
The candidate will contribute to data analysis and interpretation, manuscript preparation, and dissemination of results at national and international conferences/meetings. The candidate must hold a Master's degree in engineering, physics, or a related discipline. Experience in numerical modeling is a plus.

Location:
The PhD will take place at ONERA (https://www.onera.fr/en) at the Châtillon site.

Contexte de travail

This PhD project is part of a program funded by an ASIC agency focused on developing technologies for packaging in harsh environments.

Host laboratory: ONERA
Department: Physics, Instrumentation, Environment, Space
Location (ONERA center): Châtillon (92)