The objective of CARBO²DERM is the development of a transdermal drug delivery (TDD) platform for the intradermal delivery of therapeutic molecules using electroporation in order to temporarily increase the permeability of the skin and make possible the delivery of molecules whose size is too large to allow a simple passive diffusion. In CARBO²DERM, two TDD mechanisms are targeted, diffusion and electrophoresis, which concern neutral and charged molecules, respectively. These two mechanisms condition the type of interaction between the molecule and the reservoir. This reservoir is the central part of our project and consists of an electrically-conducting nanocomposite which should be able to first, contain the drug without leakage in the absence of electrical stimulation and then, permeabilize the skin and release the drug when under electrical voltage. Such kind of device could open the path to eliminating the use of needles, and potentially improving the quality of care of patients, especially those needing repeated injections. Scientific challenges to accomplish this are numerous and require an interdisciplinary approach, combining Materials Science, Biophysics and Electrical Engineering. Our starting idea is to develop a platform based on a nanocomposite material containing carbon nanotubes (CNTs) with a biocompatible hydrogel polymer matrix, which could be tailored in order to host different kinds of drugs (neutral: insulin for diabetes; charged: nucleic acids for DNA vaccination) for different applications. CNTs are used to improve both mechanical and electrical properties of the nanocomposite material. The electrical behaviour of such a material is non-standard because of the complexity of the microstructure and the unavoidable presence of ions, leading to a mixture of both ionic and electronic conduction. The percolation threshold of the CNTs in such a complex system needs to be determined in order to adapt the amount of CNTs. The microstructure plays a central role on key parameters such as the amount of drug which can be stored, the release rate, the electrical conductivity and electrical stimulation conditions. The presence of CNTs is also expected to allow decreasing the voltage threshold to reach the permeabilization of the skin. The microstructure itself depends on the concentration of CNTs, their surface chemistry, the concentration and nature of polymer(s) in the hydrogel, the dispersion procedure, the elaboration process and the drying conditions (porosity), which are all interconnected. The electrical stimulation profile needs to be optimized in real conditions (skin), requiring complex in situ electrical characterization. The actual delivery (ex vivo, in vivo) also needs to be addressed. CARBO²DERM aims to overcome these scientific challenges to allow the development of an original (no existing equivalent) and versatile TDD platform in which the nature and composition of the nanocomposite can be tailored depending on the application, with very promising potential in the biomedical field.

Power electronics (PE) is the key technology to control the flow of electrical energy from the source to the load. New developments in PE allow the increase of the total power density of the conversion systems through the advances in: semiconductor technology (wide band-gap semiconductor), packaging materials, system integration and design reliability. However, this also increases the electric field, thus stressing electrically more and more the insulating materials. Field reinforcements in insulating polymers can reach critical values, resulting in space-charge build-up, partial discharge activity, treeing or even breakdown of the solid materials. We propose a new approach to deal with field reinforcements in the polymeric dielectric materials. Appropriate dielectric properties across the dielectric will be simulated and tailored. First by elementary, then by complex structures, such as power modules; the developed materials will be processed and then characterized to determine their performance as insulators. The overall proposed strategy for material development could have an impact on the conception and use of insulators in electrical engineering (particularly in PE), since it could also be used to control other physical properties on the composites.

The FASTER-3D project proposes a breakthrough approach to address the reliability issues of standard packaging materials (encapsulation, substrate, interconnect, thermal interface material) in 3D electronic modules by replacing all of them by tailored functionalized polymer-based composites with advanced dielectric, thermal conductive, electrical conductive and thermo-mechanical properties. It is expected that the proposed multifunctional materials will allow a large reduction of the physical constraints (electrical, thermal, mechanical) into 3D integrated modules involving new wide bandgap power devices thanks to tailored stress relaxation. An efficient reduction of all the constraints with the proposed materials should have a major impact on the overall performances and reliability of the next generation of 3D power modules. Consequently, this project strongly supports the development of more efficient power electronic systems to help electrical energy saving during its conversion and distribution.

The properties of wave propagation in moving media differ from those in non-moving media. The rotation of an isotropic dielectric medium is for instance known to lead to polarisation rotation, which corresponds to a phase shift between the spin angular momentum (SAM) components of the wave, and image rotation, which corresponds to a phase shift between the orbital angular momentum (OAM) components of the wave. Compared to typical dielectrics, a rotating magnetised plasma stands out in that polarisation rotation can arise from two different contributions: Faraday rotation, which stems from the intrinsic gyrotropy of plasmas, and mechanical polarisation rotation, which stems from the medium's rotation. A rotating magnetised plasma could also provide new means to transform SAM into OAM. Understanding the implications of rotation effects on propagation is anticipated to be of importance for basic plasma physics, but also for applications including pulsars physics and light manipulation. The first part of this project will be mostly theoretical and fundamental. We will seek here to derive dispersion relations for electromagnetic wave propagation in a rotating plasma. Practically, we will build on our recent results, notably the simple case of propagation without OAM in an aligned rotator, and progressively add complexity with the goal of producing the most general model possible. We will in particular aim to include both SAM and OAM, as well as different geometrical effects. These fundamental results will then provide us with the necessary tools to examine two practical applications. The first applied problem considered here will be to examine how these effects of rotation on wave propagation could be observed in laboratory experiments. Our preliminary results indeed suggest that the effect of mechanical rotation on wave polarisation in a plasma could in principle be separated from Faraday rotation in the presence of strong magnetic fields (tens to hundreds of Teslas). Such fields have recently been achieved using capacitor-coil targets in laser driven high energy density plasma (HEDP) experiments, and we will here seek to confirm in collaboration with HEDP specialists the possibility of using these unique conditions to measure polarisation drag. Concurrently with this work on polarisation rotation in laboratory experiments, a second applied problem we will consider is the possible effects of the mechanical rotation of the magnetosphere surrounding pulsars on the polarisation of pulsars's signal received on Earth. We will notably study here, in collaboration with pulsar polarimetry specialists, how the inclusion of pulsars inclination - which is essential to pulsars' emission - in propagation model derived in the presence of rotation could explain certain experimental polarimetric observations, and in turn confirm our theoretical conjecture that polarisation could be uniquely used to determine the rotation direction in pulsars.

DECAIR aims to demonstrate the scientific and technological feasibility of a roll-to-roll plasma process at atmospheric pressure in air applied to the deposition of a thin and homogeneous layer. To keep the substrate intact and to realize a homogeneous coating on a large-scale surface, we will use a Dielectric Barrier Discharge (DBD). DBDs have been studied since the beginning of the century to realize thin layer coatings in nitrogen or rare gas atmosphere. In both cases, the quality of the coating is influenced by the regime of the discharge. When the discharge is filamentary, the coating is porous and fails to become dense. It consists of a large number of nanoparticles stacked together. By contrast, when the discharge is homogenous, the energy is uniformly transferred on the surface, then the coating is thick and consists on a homogeneous layer. Working in the homogenous mode will therefore be essential in the context of this project. To obtain a homogeneous discharge in a DBD, different pre-ionization mechanisms are required in order to create seed electrons prior to the ionization. These seed electrons result from a memory effect of the previous discharge. In rare gases or in nitrogen, the memory effect mainly depends on gas mechanisms. For a long time, it was considered impossible to obtain a diffuse discharge in air. However, recent studies as well as our preliminary results prove the opposite. Unlike in the other gases, the memory effect in air seems restricted to mechanisms occurring on the dielectric surface. Up to date, this process has not been precisely characterized. To fill this gap in knowledge, it is urgent to measure the electric charge dynamics on the dielectric during the discharge process. An interesting technique to quantify these electric charges in-situ is based on the electro-optic Pockels effects. This technic coupled to a systematic analysis of the dielectric material and the working conditions of homogeneous discharges will help understand the memory effect in air at atmospheric pressure. Simultaneously, the optimal working conditions will be established. Moreover, an optimization of the power transferred to the discharge will be carried out through a careful design of the power supply. After this optimization, it will then be possible to work at higher frequencies and at higher applied voltages, while remaining in diffuse discharge. With the increase of the excitation frequency, gas phase mechanisms are susceptible to play a non-negligible role. These mechanisms will be studied with a 1D Kinetic model and advanced optical diagnostic (OES, LIF). We will then realize SiOx coatings from the organosilicon precursor HMDSO. The choice of this precursor is due to its well-known dissociation mechanisms and our expertise working with it. We will first study the influence of the coating on the memory effect, before analyzing the coating properties and the deposition speed. The analysis of all the realized coatings will bring out the optimal conditions to obtain a dense coatings in air. These coatings will be compared to reference deposits made in atmospheric N2 homogeneous discharge. We will then demonstrate the feasibility to performing a dense and homogeneous coating of SIOx using a DBD at atmospheric pressure in air. From a scientific point of view, this project is designed to address fundamental questions, which critically limit our current understanding of the mechanisms behind homogenous DBD in air. Moreover, this process will be transferable to an industrial process through a slight modification of an existing Corona reactor treatment. The current atmospheric pressure processes use nitrogen or rare gas. By using only dry and filtered air, the financial and energetic costs of the process will be drastically reduced, which will make the coating of thin films more respectful of the environment.