High-power electronic devices, such as supercomputers, generate considerable heat. If this heat is not transferred away from the device’s internal circuitry, the circuits will overheat, significantly reducing the lifetime of the device, causing faults and total device failure. Thermal management materials featured by tailored thermal properties are used to dissipate heat away from device circuitry. However, current substrate materials are restricted by their properties and/or high cost of manufacturing. This proposed project will explore the feasibility to cost-effectively produce a metal/diamond composite with a high thermal conductivity by using 3D printing technology. This research aims at both advancing fundamental understanding of 3D-printed metal matrix composites and the development of improved manufacturing technologies, particularly for copper/diamond and aluminium/diamond composites via interface engineering. This joint project puts together excellence of the four laboratory partners: ICMCB Université de Bordeaux/CNRS, UMET Université de Lille, ICB-LERMPS Université de Technologie Belfort-Montbéliard, and I2M Université de Bordeaux/CNRS. 3 SMEs agreed to participate to this project: 1) Lifco Industry subcontractor for thin film deposition of a small batch of diamond powder by PVD, 2) BV Proto which will potentially benefit from the outcome of the project linked with possible optimization of SLM machine and 3) Minapack Technologies which already fabricate and commercialize MMC materials for heat sink applications and which will potentially be interested in the intellectual properties developed during this project. The objectives and research hypothesis in the three main work packages are detailed below: WP1 : focus on advancing fundamental understanding for determining how the interphase characteristics affect interfacial thermal conductance (ITC) and thermophysical properties of the 3D-printed metal/diamond composites. A model metal (Al and Cu)/carbide-forming-element interlayer/diamond structure, similar to actual interfaces in the metal/diamond composites, will be prepared using physical vapour deposition (PVD) and/or other proper techniques and further annealing. Direct measurement of ITC values, using a modulated photothermal radiometry technique, will be performed on such model materials and correlated with the interphase structure characterized by electron microscopy. Kinetics of the model materials during the SLM process will be stimulated using a “home-made 3D printer. WP2 : focus on technological advancement by developing a scalable and cost-effective sol-gel (and PVD)/satelliting process to produce a diamond core-shell powder coated with fine metal (Cu and Al) alloy particles for 3D printing using a commercial SLM machine; Interface tailoring and homogenous integration of the diamond particles in the SLM-processed component will be simultaneously figured out by introducing a nanoscale carbide-forming-element interlayer in between the diamond core and Al (or Cu) outer layer; identify the relationship between 3D printing process and metal/diamond composites’ microstructure and thermophysical properties (e.g. density, TC). WP3: focus on revealing detailed interphase configurations of the metal/interlayer/diamond composite powders and components and the model materials, such as the geometry, bonding, chemistry and structural defects and interfacial reactions, by using in-depth characterization at length scales from the micro down to nano- and/or atomic scales. Correlate interphase as well as matrix microstructure with thermophysical properties to develop an understanding of the mechanism of microstructure formation during the 3D printing process.

Decarbonization, the cost of energy, or digitalization, are all issues that are pushing the industry to undergo profound transformation. To do this, manufacturers need to monitor new parameters and therefore install many sensors. These sensors are basic (temperature, pressure, gas...) but their wiring is expensive. The alternative offered by industrial IoT (Internet of Things) battery-powered sensors is interesting when data transmission is infrequent. However, if it is a question of monitoring, the lifetime of the battery decreases, which raises the problem of the costs linked to their change, and on the other hand of their environmental impact (billions of batteries required worldwide). It is therefore necessary to find a source of energy to power these sensors. Today, 33% of the energy consumed by industry in France is lost in the form of waste heat, this form of energy is therefore well suited for this task because it is omnipresent in the industrial environment, abundant and free. Today the start-up MOÏZ, coordinator of the IoTEGH project, offers a range of autonomous industrial sensors using standard thermogenerators (TEG) based on Bi2Te3. Unfortunately, these sensors, which are not very compact and specific, are reserved for niche markets. To expand their market, MOÏZ wishes to miniaturize these thermogenerators by integrating a breakthrough technology, patented and developed at the Néel Institute (NEEL). This technology uses planar thermoelectric nano-generators (nanoTEGs) currently functionalized with thin layers of Bi2Te3. This material is standard for use in massive form but the specificities of nanoTEGs mean that it is not the most suitable in the case of thin layers. In this context, the IoTEGH project proposes to develop nanoTEGs based on the Fe2VAl (Full Heusler) material, which is more conductive, more abundant and less toxic, and therefore better suited to this application. These nanoTEGs could generate sufficient electrical power to supply connected sensors completely autonomously, without batteries or wires, by recycling waste heat lost in industrial processes and infrastructures. Initial tests, conducted by the Institute of Chemistry and Materials Paris-Est (ICMPE) and the Néel Institute (NEEL) on Fe2VAl, gave a favorable result which was thus published: the good thermoelectric properties obtained for a composition of bulk material (ICMPE) were reproduced when the same composition was deposited as a thin film (NEEL). The optimal compositions already determined at the ICMPE for n-type Fe2VAl can thus serve as reference compositions for films. New p-type Fe2VAl compositions to achieve the required specifications will be searched at ICMPE in bulk form. The processes for depositing thin layers of these alloys will then be developed by NEEL using a poly-target sputtering frame making it possible to reproduce the good thermoelectric properties reached at ICMPE. The n- and p-type thin layers will then be included by MOÏZ on Si-N membranes for the development of nanoTEGs via microelectronics processes. The thermoelectric performance of thin films and nanoTEG devices will be measured using specific instrumentation. The collaboration between ICMPE, NEEL and MOÏZ brings together all the skills and knowledge necessary for the successful completion of this ambitious project. The success of the IoTEGH project will lead to an easily integrable technology, comprising only non-toxic and available materials, capable of responding to the problem of the autonomy of industrial IoT sensors.

The SWITCH project is a European doctoral network that is currently being built to support the transition from the known synthesis of switchable molecules to their implementation into operative devices. For that purpose, a consortium of experts in spin crossover systems (chemistry, properties and modelization) has started to be built and needs to be reinforced to cover as much as possible the main current challenges of molecular materials sciences for chemosensors, molecule-based electronics and barocaloric refrigeration. The scientific complementarity of the partners will be an asset for both the success of the various challenges tackled as well as for the high-level training of the doctoral candidates hired in the frame of this project. Indeed, up to fifteen doctoral candidates are planned in chemistry, physics and theoretical laboratories. Various actions will be planned to level-up their skills and create a network of young researchers for future collaborations. The MRSEI action will help building this doctoral network project by funding travels and a graphic designer to improve the quality of the project presentation.

The plant primary cell wall is a complex structure composed of polysaccharides and proteins. It plays a central role in the control of plant growth and development, therefore in the production of biomass. Pectins are major components of the primary cell wall, representing up to one third of the wall dry mass, and are widely used in the food industry, as gelling agents. Among pectins, homogalacturonan (HG) is a homopolymer of ?-1,4-linked-D-galacturonic acid units that can be methylesterified and acetylated. Over the recent years, HG-type pectins have been reported as major actors of the modulation of the mechanical properties of the cell wall. They can mediate changes in growth, through the action of remodeling enzymes that fine-tune the degree of polymerization (DP) - polygalacturonase (PG) or pectin/pectate lyases (PLLs) - or of methyesterification/acetylation (DM/DA) of the polymer - pectin methylesterase, PME or pectin acetylesterase, PAE. Up to now, the combination of developmental biology and biophysics has started to shed light on the cell wall mechanical effectors that mediate changes in cell shape. However, our understanding of the mode of action of pectin remodeling enzymes is impaired by gene redundancy (enzymes are all encoded by multigenic families of 12 to 69 members), as well as by the occurrence of compensation mechanisms among gene families and cell wall polymers. The objectives of the WALLMIME project will be thus to: i) Biochemically characterize a set of HG remodeling enzymes (PME, PAE, PG, PLL), ii) Comprehensively follow their effects upon application on both etiolated hypocotyls and biomimetic model of cell wall, iii) Build a model of the dynamics of HG-pectin remodeling. To tackle these objectives, the WALLMIME project will use two distinct models. On one hand, mimetic membranes/films combining cellulose microfibrils and pectins of various structures (DM, DA, DP), will be used as a simplified well-controlled system to determine the role of pH, ionic strength and calcium ions concentration, which are key effectors of apoplast homeostasis, on the dynamic of the pectic network. On the other hand, Arabidopsis dark-grown hypocotyl, a standard developmental model that is solely characterized by cell elongation, will be used to relate the modifications of the pectin network to phenotypical changes. The WALLMIME project will be organised in 4 scientific Work Packages (WP) and one management WP. The originality of the organization lies in the fact that the three firsts scientific WP (WP1: Consequences of HG-enzymes action on polymer structure and cell integrity, WP2: Consequences of HG-enzymes action on mechanical properties, and WP3: Consequences of HG-enzymes action on elongation/deformation) will be performed on the Arabidopsis hypocotyl and on mimetic cell wall in parallel. This will allow getting the best benefit from the highly complementary expertise of the three partners. WP4 (Integrated model of the dynamics of pectic network) will build a model of the dynamics of pectic network using the experimental data generated in WP1 to 3. Bringing experts from various fields (enzymology, biophysics, polysaccharide chemistry, glycomaterials), WALLMIME will drastically increase our knowledge on how plants can fine-tune their cell wall pectic matrix and how this can mediate changes in plant growth. This is of the utmost importance to understand how plants can respond to the environment and can produce biomass. The project will further challenge the current concepts of plant cell wall and will contribute to setting new standards for dynamic cell wall models. This is currently a highly competitive field for which the project will be an original contribution, as it combines the characterization of the effects of enzymes on plant material and biomimetic models. It will thus contribute to a better understanding of the enzymes’ mode of action on substrates, paving the way for novel use of plant enzymes in glycomaterials.

Neutrinoless Double Beta Decay (0v-DBD) is in a central position for the study of elementary particles and fundamental interactions. It has strong implications on topics of cosmological character as well. After the discovery of neutrino flavor oscillations, crucial issues remain open, such as the absolute neutrino mass scale and the mass hierarchy, together with the quest of the neutrino nature: Dirac or Majorana fermion? The purpose of this project, named LUMINEU, is to set the bases for the realization of a next-generation 0v-DBD experiment with unprecedented sensitivity. To succeed, LUMINEU proposes to reduce the residual background due to alpha particles owing to the simultaneous measurement of the light and the heat generated in a nuclear event. This double read-out approach will allow rejecting interactions due to alpha particles with efficiency close to 1. If the scintillating bolometers contain a candidate to 0v-DBD with transition energy higher than the natural gamma radioactivity end-point (2.6 MeV), the rejection of alpha particles enables a virtually zero-background experiment for the exposures required to scrutinize the inverted hierarchy region of the neutrino mass pattern. LUMINEU envisages the study of large ZnMoO4 scintillating crystals, containing the excellent candidate 100Mo, which is featured by a Q-value around 3 MeV. The ZnMoO4 crystals will be grown with an advanced technique which warrants excellent crystal quality, extreme purity and negligible waste of the starting material. A mass of 400 g for the single module is foreseen. The rejection of alpha particles is correlated to the quality of the light measurement. A special effort will be dedicated to the optimization of the scintillation light detectors in terms of energy threshold, size, reproducibility and time response. Reducing this time would be the key in case of ultimate background due to the pile-up of standard DBD with neutrino, particularly relevant in the case of 100Mo. As a consequence, beside the production of standard semiconductor sensors (NTD) by nuclear transmutation, new sensors will be studied: high impedance superconductive films and metallic paramagnetic thermometers. The coupling of such sensors to massif crystals without loss in their nominal performances would be a strong innovation. This result would have an impact on astroparticle physics beyond the 0v-DBD. This may lead to important advancements in dark matter direct detection in EDELWEISS-3 and EURECA. The progress in thermal sensors and their coupling, will lead to the improvement of the energy resolution and threshold of the heat channel and to a better sensitivity to WIMPs in particular at low masses. LUMINEU will take advantage of contributions from both communities. In the same time, both field of research will take benefit of LUMINEU’s developments. The results on the scintillating crystals and on the light detectors will enable a 0v-DBD pilot experiment performed in an underground environment and containing a considerable amount of enriched molybdenum (about 1 kg). After the conclusion of LUMINEU, the realization of a large-scale experiment looking at the 20 meV region for the effective neutrino mass will be just a matter of political will and fund availability.