Ultra-low frequency wireless power transmission for sensor node charging
Wireless power transfer (WPT) technologies are rapidly expanding, particularly for wireless charging of everyday electronic devices and for powering wireless communicating sensor nodes. However, their transmission ranges remain limited, and the high operating frequencies typically used prevent energy transfer in the presence of, or through, conductive media (such as metallic barriers or seawater). This constraint significantly limits their adoption in complex environments (industrial, biomedical, etc.).The ultra-low-frequency technology investigated in our laboratory is based on an electromechanical receiver system comprising a coil and a magnet set into motion by a remotely generated magnetic field. The objective of this PhD project is to propose and develop novel ultra-low-frequency concepts to increase transmission range while maintaining sufficient power density for supplying sensor systems. The work will therefore involve studying, designing, optimizing, and experimentally validating the performance of new topologies (emitter field shaping, receiver geometries and materials, etc.). The candidate will develop analytical and numerical models to identify key system parameters and compare performance with the state of the art (range, power density, sensitivity to orientation). In addition, the candidate will propose, design, and experimentally evaluate innovative energy conversion electronics, on the transmitter and/or receiver side, to assess their impact on the overall system performance. A joint optimization of the electromechanical system and its associated power electronics will ultimately lead to the realization of a high-performance wireless power transfer system. A multidisciplinary profile with a strong orientation toward physics and mechatronics is sought for this PhD project. In addition to solid theoretical foundations, the PhD candidate must demonstrate the ability to work effectively in a team environment as well as a strong aptitude for experimental work. The PhD candidate will be integrated into the Systems Department of CEA-Leti, within a team of researchers with strong expertise in the development and optimization of electronic and mechatronic systems, combining innovative solutions for energy harvesting, wireless power transfer, low-power electronics, and sensor integration aimed at the development of autonomous systems.
Acoustic and Ultrasound-based Predictive Maintenance Systems for Industrial Equipment
Power converters are essential in numerous applications such as industry, photovoltaic systems, electric vehicles, and data centers. Their conventional maintenance is often based on fixed schedules, leading to premature replacement of components and significant electronic waste.
This PhD project aims to develop a novel non-invasive and low-cost ultrasound-based monitoring approach to assess the state of health and remaining useful life (RUL) of power converters deployed across various industries.
The research will focus on identifying and characterizing ultrasonic signatures emitted by aging electronic components, and on developing physics-informed neural networks (PINNs) to model their degradation mechanisms. The project will combine experimental studies with advanced signal processing and AI techniques (compressed sensing), aiming to detect early signs of failure and enable predictive maintenance strategies executed locally (edge deployment).
The research will be carried out within a Marie Sklodowska-Curie Actions (MSCA) Doctoral Network, offering international training, interdisciplinary collaboration, and secondments at leading academic and industrial partners across Europe (Italy and Netherlands for this PhD offer).
Instrumented PCB for predictive maintenance
The manufacturing of electronic equipment, and more specifically Printed Circuit Boards (PCBs), represents a significant share of the environmental impact of digital technologies, which must be minimized. Within a circular economy approach, the development of monitoring and diagnostic tools for assessing the health status of these boards could feed into the product’s digital passport and facilitate their reuse in a second life. In a preventive and prescriptive maintenance perspective, such tools could extend their lifespan by avoiding unnecessary periodic replacement in applications where reliability is a priority, as well as adapting their usage to prevent premature deterioration.
This PhD proposes to explore innovative instrumentation of PCBs using ‘virtual’ sensors, advanced estimators powered by measurement modalities (such as piezoelectric, ultrasonic, etc.) that could be integrated directly within the PCBs. The objective is to develop methods for monitoring the health status of the boards, both mechanically (fatigue, stresses, deformations) and electronically.
A first step will consist of conducting a state-of-the-art review and simulations to select the relevant sensors, define the quantities to be measured, and optimize their placement. Multi-physics modeling and model reduction will then make it possible to link the data to PCB integrity indicators characterizing its health status. The approach will combine numerical modeling, experimental validations, and multiparametric optimization methods.
Optically Pumped Magnetometers based on helium-3
The laboratory, reknown for its expertise in high-resolution and high-precision magnetic measurements, has been developing and providing for several decades successive generations of optically pumped helium-4 magnetometers. These instruments serve as reference sensors aboard the ESA Swarm mission satellites launched in late 2013, and will also equip the forthcoming NanoMagSat mission, scheduled to launch from the end of 2027 onward.
In an effort to diversify its activities and to address emerging applications involving autonomous or “deploy-and-forget” sensors, where power consumption constraints are particularly demanding, the laboratory now aims to develop a new magnetometer technology based on helium-3 atoms as the sensitive medium. The lifetime of the helium-3 atomic state used for magnetic field measurement is significantly longer than that of the equivalent helium-4 state. This property enables a substantial reduction in optical pumping requirements, thereby offering the prospect of improved energy efficiency and power consumption.
The objective of this research is to advance the Technology Readiness Level (TRL) of this helium-3-based magnetometer architecture, with the ultimate goal of realizing an instrument that combines outstanding metrological performance with exceptional energy frugality, suited to these highly specific and constrained applications.
Accordingly, the purpose of this PhD work will be to design, implement, and experimentally evaluate a helium-3 magnetometer architecture capable of fulfilling these performance and efficiency objectives.