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

PhD : selection by topics

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Modeling phase transitions in LIB active materials

Département de l'Electricité et de l'Hydrogène pour les Transports (LITEN)

Laboratoire Modélisation multi-échelle et suivi Performance

01-09-2020

SL-DRT-20-0851

marion.chandesris@cea.fr

Electrochemical energy storage incl. batteries for energy transition (.pdf)

For Generation 3 lithium-ion batteries (LIB), the materials have reached a fair maturity level and current challenges focus on optimization of these technologies under various and most of the case antagonist constraints. Modeling and simulation numerical tools allow to tackle these optimization questions but suffer from a low knowledge of active materials physical and electrochemical properties. The aim of this thesis is to investigate the link between the crystallographic structures of LIB active materials and their thermodynamic properties at and out of equilibrium. In particular, this thesis work aims at modeling and simulating phase transitions occurring during lithium insertion in lamellar active materials (graphite at the negative and alloy of transition metal oxide at the positive) to understand (i) staging phenomena, which corresponds to periodic ordering of lithium and (ii) shift in the planes of the host materials. Progress in our understanding of these two phenomena and their coupling should bring a better comprehension of the main physical properties of a large majority of lamellar active materials.

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Task oriented gripper design methodology for robotic manipulation ? application to pluridigital grippers with flexible joints

Département Intelligence Ambiante et Systèmes Interactifs (LIST)

Laboratoire d'Architecture des Systèmes Robotiques

01-09-2020

SL-DRT-20-0852

florian.gosselin@cea.fr

Factory of the future incl. robotics and non destructive testing (.pdf)

Robots are increasingly visible in our environment, with applications in e.g. fruits and vegetables picking, food packaging and human-robot interactions. All these applications require an efficient solution for grasping and manipulating many different objects. Several approaches have been proposed so far to solve this issue, ranging from double jaw pliers which are very efficient for the grasping of specific tools but cannot deal with other objects nor manipulate them finely, to pluridigital grippers which offer a higher grasping stability and can be reconfigured to grasp various objects. The latter's mechanical complexity and control difficulty however still limit their use in practice to grasping tasks and slow their spread in industry and service robotics. This thesis aims to solve these limitations by combining innovative technological solutions based on the latest advances in flexible structures and 3D printing, distributed sensors and actuators, with task oriented mechanisms synthesis methods, to develop a task oriented design methodology for versatile grasping and dexterous manipulation mechanisms. This methodology will be used for the design and control of novel grippers making use of innovative and adaptive structures that conform automatically to the objects' geometry and can generate sufficiently large in-hand movements. These developments will be validated experimentally on one or several demonstrators.

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Design of a 3D stacked smart imager dedicated to neural network processing

Département Architectures Conception et Logiciels Embarqués (LIST-LETI)

Laboratoire Adéquation Algorithmes Architecture

01-10-2020

SL-DRT-20-0855

stephane.chevobbe@cea.fr

New computing paradigms, circuits and technologies, incl. quantum (.pdf)

The 3D stacked silicon technologies allow the fabrication of new kinds of smart vision sensors by vertically coupling image sensor and specific processors or memories inside the same chip. Some research teams develop 3D stacked vision chip either to increase the quality of the sensor or to embed high powerful processors inside the chip closely coupled to the imager, as we did by developing the RETINE chip. Deep neural networks are widely used in many application domains including computer vision. A lot of research consists in increasing the power efficiency and decreasing the power consumption of embedded systems dedicated to neural networks execution. In this PhD thesis we propose to evaluate the opportunities offered by 3D stacked silicon technologies to question and envision new kind of digital 3D stacked vision chip embedding neural network hardware. In this PhD thesis we wish to study the contribution of 3D integration technologies in an intelligent imager integrating neural network processing functions. We will focus this study mainly on deep neural networks, however other types of neural networks can be evaluated. The architectural contribution expected from this thesis is the study and design of an efficient and low-power computing architecture that meets the high constraints imposed by deep neural networks, namely the need for very regular high-performance computing and the very high need for memory

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Suspended vertical diodes for LWIR detection

Département d'Optronique (LETI)

Laboratoire d'Imagerie thermique et THz

01-09-2020

SL-DRT-20-0856

patrick.leduc@cea.fr

Photonics, Imaging and displays (.pdf)

Uncooled thermal detectors absorb the infrared flux for wavelengths from 7µm to 14µm. This corresponds to an atmospheric transmission window and to the maximum emission of a blackbody at 300K, which enables the detection of temperature variations of less than 100mK. The operating principle of microbolometers is based on the temperature measurement of a suspended membrane absorbing the infrared flux. The thermal transducer is the sensitive element of the microbolomètre, which determines its signal-to-noise ratio and therefore the performance of the bolometric pixel. In recent years, the miniaturization of microbolometer technologies has led to pixel size reduction down to 12 µm and has been accompanied by a reduction of manufacturing costs. However the current technology reaches its limits in a way that it becomes extremely difficult to pursue the pixel size reduction. The thesis topic is the study of a breakthrough technology for microbolometers. Unlike conventional detectors, which use thermistor for the thermal transduction, the proposed research topic will examine an original technology based on vertical diodes. The subject will focus on characterizing and modeling the performance of such a device.

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Random number generators ? Tests and exploitation of vulnerabilities

Département Systèmes (LETI)

Centre d'Evaluation de la Sécurité des Technologies de l'Information

01-10-2020

SL-DRT-20-0857

cecile.dumas@cea.fr

Cyber security : hardware and sofware (.pdf)

The embedded cryptography in smart card amply uses random numbers in order to guarantee uniformity properties or to hide information. In practice these numbers are generated by the chip from a hardware unit named TRNG (True Random Number Generator). The evaluation of this generator requires on the one hand to characterize the statistical properties of generated numbers and on the other hand to verify its resistance to side channel attacks. This thesis proposal is to study methods of evaluating the generator quality, to characterize the defects observed at the output and to analyze the ways of exploiting these vulnerabilities when using numbers that are not quite random.

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Development of superconducting single photon detectors and receiver circuits for quantum communications

Département d'Optronique (LETI)

Laboratoire d'Intégration Photonique sur Silicium

01-10-2020

SL-DRT-20-0859

segolene.olivier@cea.fr

Photonics, Imaging and displays (.pdf)

Quantum information processing turns out to be a major challenge for our society with the development of quantum computers, able to solve complex problems much more rapidly than a classical computer, and of quantum communications providing absolute security for information transfer. The development of integrated technologies is essential for the future large-scale deployment of compact and low-cost quantum information systems. CEA-Leti has been developing for several years a silicon photonics platform, providing integrated components and circuits for various applications such as telecom/datacom, lidars and more recently quantum communications. The objective of this PhD is in a first step to design, fabricate in the Leti clean room and characterize a new generation of advanced superconducting quantum detectors on Silicon able to detect single photons with above 90% efficiency. In a second step, these detectors will be integrated into secure quantum communication circuits. This PhD will benefit from collaborations with academic laboratories in France and in Europe.

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