Scientific direction Development of key enabling technologies
Transfer of knowledge to industry

PhD : selection by topics

Technological challenges >> Cyber physical systems - sensors and actuators
6 proposition(s).

Integration of piezoelectric-based power converters

Département Architectures Conception et Logiciels Embarqués (LIST-LETI)

Laboratoire Intégration Gestion d'Energie Capteurs et Actionneurs

SL-DRT-20-0286

adrien.morel@cea.fr

Cyber physical systems - sensors and actuators (.pdf)

The aim of this thesis is to integrate high-efficiency power converters based on resonating piezoelectric transducers. A large part of the work is to develop the integrated circuit to handle high switching frequency operation while maintaining an adiabatic energy transfer. Based on our recently published results [Pollet2019], the integration of the power stage and the control between phases paves the way of the miniaturization of the piezoelectric transducer using microelectronics process. The PhD student will cover the sizing, IC design, electro-mechanical characterization and feedback control of miniaturized piezoelectric-based power converters. [Pollet2019] B. Pollet et al., A New Non-Isolated Low-Power Inductorless Piezoelectric DC?DC Converter, Trans. on Power Electronics, 2019.

Download the offer (.zip)

Piezoelectric MEMS actuator hydraulically amplified

Département Composants Silicium (LETI)

Labo Composants Micro-actuateurs

01-09-2020

SL-DRT-20-0488

laurent.mollard@cea.fr

Cyber physical systems - sensors and actuators (.pdf)

The main objective of micro-actuators research is an architecture that can generate large displacements and forces over a wide frequency range, while not consuming a significant amount of electrical power. To date, no solution meets all these criteria. Indeed hydraulic actuators do not meet the criterion of compactness and frequency but allow significant force and displacement. Similarly, electromagnetic actuators have a good frequency range with excellent force and stroke output, but they are generally heavy and require significant electrical current. Piezoelectrics are also known for their excellent operating bandwidth and can generate large forces in a compact size, but traditionally they have very small displacements. The technological breakthrough of the thesis will consist to develop a hydraulic amplification mechanism, by applying small displacements on a large surface, sa as to move a liquid, and to generate, by conservation of the volume, important displacements on a weaker moving surface. Therefore, the thesis will consist to develop and integrate into a MEMS (Micro Electro-Mechanical System) system, this hydraulically amplified piezoelectric actuator (called HDAM system for "Hydraulic Displacement Amplification Mechanism") and optimize it

Download the offer (.zip)

Adaptative frequency tuning electronic systems for broadband vibration energy harvesting

Département Systèmes (LETI)

Laboratoire Autonomie et Intégration des Capteurs

01-09-2020

SL-DRT-20-0530

pierre.gasnier@cea.fr

Cyber physical systems - sensors and actuators (.pdf)

Energy harvesting is a theme whose aim is to supply power to wireless sensor nodes by replacing the source of electrical energy (battery, cables) with ambient energy. Vibration energy harvesting, in particular, makes it possible to exploit the mechanical energy of an environment and convert it into electricity in order to supply a wireless sensor node. The thesis will focus on the exploitation of piezoelectric materials on resonant structures to convert vibration energy into electricity. The use of mechanical resonators amplifies ambient vibrations, but the harvested power drops sharply when the spectrum of ambient vibrations no longer coincides with the harvester's resonant frequency. For the adoption of this type of system by industry, one of the major obstacles is therefore this frequency selectivity. The CEA and the University of Savoie Mont-Blanc (SYMME Laboratory) have recently proposed high-performance techniques to solve this problem by using harvesters that can be dynamically tuned by an electronic system. Indeed, coupled with intelligent electronics, a "strongly coupled" harvester has its mechanical behavior modified (its resonance frequency in particular), making it possible to follow the evolution of the input frequency. The objective of the thesis is to propose, dimension, simulate, fabricate and test innovative electronic architectures (based on discrete components and/or microcontrollers) allowing the automatic tuning and the search for the maximum power point of piezoelectric vibration energy harvesters. Particular attention will be paid to the low power and small size of the electronic architectures since the ultimate goal is to propose an autonomous circuit consuming a negligible part of the harvested electrical energy. At the end of the thesis, the selected architecture(s) will then be proposed to the CEA-Leti's integrated circuit department for miniaturization. A complete demonstrator (harvester, micro-converter and adjustment circuit) is targeted for the end of the thesis.

Download the offer (.zip)

Low-frequency wireless power transmission for autonomous systems

Département Systèmes (LETI)

Laboratoire Autonomie et Intégration des Capteurs

01-09-2020

SL-DRT-20-0615

pierre.gasnier@cea.fr

Cyber physical systems - sensors and actuators (.pdf)

Wireless power transmission (WPT) technologies are expanding rapidly, particularly for wireless charging of electrical systems (phones, electric vehicles, etc.). However, these technologies have a limited transmission range and their high operating frequency prohibits any transmission of energy in the presence or through conductive media (metal walls or seawater), which limits their adoption in complex environments (industrial, military...). The low-frequency WPT technology we propose is based on an electromechanical system comprising two coils and a magnet. This type of technology has the advantage of being able to power wireless sensor nodes for a variety of applications (health monitoring of structures in isolated environments is one example among others). The purpose of the thesis is to study the addition of a piezoelectric converter at the receiver side. This so-called "hybrid" system (electromagnetic/piezoelectric) will take advantage of each converter, in order to improve the receiver's performance and ultimately increase the maturity of the technology (increase in range, power densities, etc.). In this context, the thesis will consist in studying, developing and testing the performance of hybrid WPT solutions. The candidate will develop analytical and numerical models to identify the parameters of influence of the coupled system and compare its performance to the literature. The candidate will also have to develop adapted innovative energy conversion electronics. A joint optimization of the electromechanical system and its associated electronics will lead to the development of a complete high-performance wireless power transmission system. The final goal of the thesis is to analyze and understand the advantages and limitations of this hybrid technology. A multidisciplinary profile oriented towards physics and mechatronics is sought for this thesis. In addition to a solid theoretical background, the candidate must have teamwork skills and an ability for experimentation. The student will integrate the Systems Division 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 transmission, low-power electronics and sensor integration for the development of autonomous systems.

Download the offer (.zip)

Innovative haptic interface

Département Composants Silicium (LETI)

Labo Composants Micro-actuateurs

01-09-2020

SL-DRT-20-0724

fabrice.casset@cea.fr

Cyber physical systems - sensors and actuators (.pdf)

A haptic interface allows to the user to interact with its environment by the sense of touch. It can be used for example to give complex information in harsh, noisy or low visibility environment. Today, demonstrators provide haptic effects essentially on glass screen. We propose to develop innovative haptic solutions to generate complex effects on curved surfaces, conformable, and potentially in various materials such as metal, plastic? The objective of the candidate will be to design, build and characterize haptic interfaces. A reflection will be conducted on the different possibilities to integrate this haptic function on various substrates. To do this, he will develop analytical models and use finite element method (COMSOL). Supervised by CEA experts on the subject, he will propose the most adapted technology (thin-film actuators or bulk piezoceramics) to integrate piezoelectric actuators able to generate the haptic effect on curved surfaces, conformable, ideally flexible. Finally, a reflection on the global system will be necessary in order to propose an innovative and complex haptic demonstrator integrating different functions such as finger position detection, actuation and driving mechanisms.

Download the offer (.zip)

Remotely powered and searchable sensors

Département Composants Silicium (LETI)

Laboratoire Composants Micro-Capteurs

01-09-2020

SL-DRT-20-0803

patrice.rey@cea.fr

Cyber physical systems - sensors and actuators (.pdf)

The need for sensors that can be remotely interrogated makes it possible to envisage new applications both in aeronautics (aircraft wing monitoring, turbine blades), energy (measurements on rotating devices), civil engineering (structural monitoring) consumer applications such as screens, health (medical patch) and also in the fields of security and defense. For these sectors, we can emphasize the interest of this type of remotely powered and searchable sensors, in all situations where a sensor must be placed in an inaccessible location, where the sensor can be buried, in harsch environment for electronics or batteries (high temperature, explosive atmosphere, etc ...), where it can not be electrically connected to the outside (rotating machine, cramped space, etc ...). The "M&NEMS" sensor technology developed by CEA-LETI can meet this need for extreme miniaturization, ultra-low consumption, high performance and low cost. In addition, CEA-LETI is also working on passive sensors with electromagnetic transduction integrating a miniature antenna, sensors that have a very strong interest to be read remotely by an interrogating antenna. This type of sensor coupled to an antenna without an electronic circuit can also enable an increase of the interrogation distance between the reader and the remote-powered sensor, compared to RFID tags that require energy to wake up the circuit. The challenge is to couple and integrate these silicon sensors with an antenna architecture (co-design). The work will consist of designing and manufacturing antenna-sensor systems by jointly studying each of the two components in order to optimize the coupling in remote power and remote transmission. This will require close interaction between the sensor design and the antenna. Several types of sensors operating in static mode or in resonant mode can be studied. To carry out this multidisciplinary work, the PhD student will rely on the expertise and resources of several CEA-LETI laboratories: the Sensors Laboratory (LCMC), the Tests and Reliability Laboratory (LCFC) of the Silicon Components Department and also on the Antenna, Propagation and Inductive Coupling Laboratory (LAPCI) of the Systems Department as well as on a technological platform for the sensor manufacturing. It will be able to collaborate with other PhD students involved in this theme, especially for the design part of the adapted antenna

Download the offer (.zip)

Voir toutes nos offres