(en anglais) Machine Learning for Enhanced Silicon Photonics Devices
A partir de février 2024
We are seeking a postdoctoral researcher with interest and experience in integrated photonics to join the Silicon Photonics team at the Center for Nanoscience and Nanotechnology (C2N). This project stems from a longl asting collaboration with the National Research Council Canada (NRC) and aims at developing accurate silicon photonics surrogate models using machine learning. In particular, we will address the key open challenge of modeling the impact of fabrication and operation environment on the perfromance of photonic devices. We will exploit both simulations and optical measurements in a data-efficient manner, and leverage transfer learning and active learning methods. The developed models will then be used to anticipate and pre-emptively compensate for fabrication errors, providing an innovative approach to design and calibrate large photonic circuits
The successful candidate will be responsible for the design and layout of photonic components and circuits to be used as test cases; fabrication of the devices in the C2N clean room and their experimental characterization to build the dataset required for neural network training; identify, implement, and train neural network architectures both for optical behavior prediction and inverse design purposes. Activities will be carried out in collaboration with the PI and the NRC team. Short stays in Ottawa (Canada) are foreseen as part of the project.
(en anglais) Development of a crystalline oxide-based resonant magnetic sensor
A partir de décembre 2023
Within the C2N OXIDE team, part of the research activities consists in taking advantage of oxide materials with perovskite structure to produce micro-devices. This aspect has been exploited for the development of sensors [1-2] but also for more fundamental studies aimed at understanding the physical properties of this class of materials produced in thin layers [3-4].
The production of MEMS (Micro Electro-Mechanical Systems) based on crystalline oxides is made possible by their integration on silicon substrates, for which the micro-structuring processes are particularly mature. Such fabrication processes of crystalline oxide MEMS are mastered in the laboratory (see figure inset).
From the sensor point of view and with the objective of bearing the necessary reduction in size of the devices, and therefore of
the signals to be measured, we have recently evolved towards devices where the quantity measured is the resonant frequency
of a vibrating element, thus allowing to gain in sensitivity when certain parameters of the sensor are correctly tuned.
In particular, we demonstrated the ability to sense magnetic field by measuring the resonant frequency of piezoelectric cantilevers
with magnetostrictive layer as top electrode (see figure). 
The objective of the post-doc will be to go beyond the existing proof of concept.
In the framework of PEPR Spin and more precisely of ADAGE project dedicated to the development of enhanced
magnetic sensors, the candidate will design, fabricate, and characterize the resonant devices. For that purpose,
the candidate will benefit from all the C2N facilities (clean room, material growth and characterization, device
characterization) and the well-established know-how of the OXIDE team for the fabrication and characterization
of perovskite-based MEMS devices.
Collaboration with the other members of the consortium is also expected to improve (i) the magnetostrictive
layer, (ii) the device geometry, (iii) the fabrication process, and (iv) the measurement approach, with the overall
objective to maximize the sensibility and the range of measurement.
Scientific articles and eventually patents are expected to be published.
• Enthusiasm and strong involvement in your project, autonomy, and the ability to address your topic as a project with milestones and deliverables;
• Taste for Materials Science, device fabrication and characterization. This work is mainly experimental, but a part of simulation can be integrated depending on the candidate;
• Ability to communicate and work in a group, an open-minded attitude, and an ability to conduct a project by addressing questions to relevant people around you.
For any questions and to apply : email@example.com
(en anglais) Assessment of an original electromagnetic non-contact continuous glucose monitoring wearable sensor in a bio-mimetic environment
A partir de décembre 2023
Scientific background. A non-contact electromagnetic wearable sensor, based on the use of original passive and inductive resonators, has been developed in recent work within C2N's Microsystems and NanoBioFluidics department, in collaboration with the SATIE Laboratory, Université Cergy Pontoise. Patents have been filed for this work in 2021 and 2022. The developed sensing approach involves flexible, passive, multi-resonant sensors in the radio-frequency (RF) range (10 MHz to 500 MHz). These planar sensors can be produced on a flexible support, and can be easily integrated into a textile or a bandage-type adhesive patch, with no directly attached electronics. This makes them completely wearable and low-cost. Remotely excited by a broadband RF inductive probe combined with control electronics (RF reader), this type of sensor can interrogate and monitor, via inductive coupling, the complex dielectric properties of tissues affected by glucose concentration, with depths of investigation well suited to subcutaneous tissues and blood vessels. Preliminary tests using a multi-resonant sensor with 8 frequencies in the RF range were successfully carried out in 2023 on saline
solutions reproducing the conductivity of subcutaneous tissues, and presenting d-glucose concentrations representative of blood glucose levels.
Objective and work program. The aim of the present project is to assess the relevance of the proposed sensing approach in a biomimetic environment closer to the in-vivo environment of continuous blood glucose monitoring. We therefore plan to size and test a set of sensors on biomimetic phantoms to be designed and developed. These phantoms will comprise artificial tissue with biomimetic dielectric properties (polymer, gels and/or saline solutions), and one or more polymeric fluidic vessels carrying blood or solutions that mimic blood properties. This device will be placed in a climatic chamber that allows us to vary the experiment's humidity and temperature conditions, as well as geometric conditions, and if necessary in biological lab environment. Finally, we will test the sensor sensitivity to the presence of other substances in the blood (paracetamol, metformin, fructose, oleic acids, etc.).
We will then conclude on the sensor robustness to these influences, and on any corrective actions that need to be taken on sensor design and/or implementation for more robust blood glucose measurements.
Expected Profile: the candidate should have a PhD degree in electrical engineering or applied physics and should be motivated for and experienced in the field of sensors for health, including micro-fluidics, micro-fabrication, and instrumentation. The candidate will have a high degree of experimental rigor, and familiar with data processing tools (Matlab, etc.) for instrumental programming and experimental data processing. Knowledge of electromagnetic sensors would also be appreciated. Fluent in English
The activities are founded though a “POC in Lab” program supported by Université Paris-Saclay.
Location: C2N, Palaiseau. Duration: 12 months, starting late 2023 - early 2024. Remuneration:
Université Paris Saclay salary scale for post-docs, depending on experience.
Contact : Pierre-Yves JOUBERT, Head of Department « Microsystems and nanobiofluidique »
Courriel : firstname.lastname@example.org