Nowadays, there is a strong interest in the development of nanostructured ceramics in order to develop materials with special or improved properties with respect to those of classical bulk ceramics. Thermoelectric nanostructures are very attractive because they can provide a practical way to scavenge energy from the environment to power microsystems and thus be used in novel self-powered sensing devices. Thermoelectric generators can be used in automobiles to convert the wasted heat from an engine's coolant or exhaust into electricity. It is accepted that such systems can lead to a fuel consumption decrease of around 10%. Heat from the sun is also a source of energy that can be converted into electricity by thermoelectric systems. A lot of thermoelectric materials have been extensively studied during the last decade. Recently, spectacular results have been obtained for various systems through the introduction of nanostructures in the materials. Nanoscale heterostructures can be achieved by decreasing the grain size and/or by introducing dispersed nanoparticles or continuous secondary phase. These systems are usually referenced as nanocomposites. Among the materials having good thermoelectric properties, some have a highly anisotropic structure. In those cases, it could be of great interest to align the grains along one crystallographic direction. Such materials are called textured ceramics and can be obtained through different ways. Nevertheless, all the existing texturing methods require long sintering time at high temperature, in order to allow the texturing process to take place. Consequently, it is rather difficult to obtain nanotextured ceramics. NanoCerTex project deals with the development of thermoelectric nanotextured materials and nanocomposites for energy harvesting, by using an original combination of a soft chemistry route nanofibers fabrication technique (electrospinning) and flash sintering technique (spark plasma sintering techniques). The key issue to overcome is maintaining the nanometric dimension during the texturing process. Two axes will be explored: - Development of bulk dense nanotextured thermoelectric ceramics. The objective will be to sinter by flash technique, a stack of aligned fibers to produce dense and bulk-textured ceramics with submicrometric grains. It is expected that for compounds with highly anisotropic crystal structure, texturing develops spontaneously during the uniaxial pressure sintering. For materials with isotropic structure, texturing can be induced by introducing some anisotropic seeds into the fibers during electrospinning. Texturing will be developped during subsequent sintering step. This method is an implementation of the well-known Templated Grain Growth method used for bulk micrometric ceramics to nanofibers. - Development of textured thermoelectric nanocomposites, which will consist on inorganic multiphase systems. The objective is to increase the Figure of Merit ZT by decreasing the thermal conductivity of the material while maintaining a high electrical conductivity. The use of aligned core-shell nanofibers should lead to nanocomposite thermoelectric ceramics with enhanced properties. NanoCerTex aims at understanding the mechanisms of fiber formation during electrospinning and texture development during the subsequent thermal treatment. In depth ex situ analysis (XRD, SE-MEB, MET, EBSD…) of the crystallization within the fiber and in situ characterization by synchrotron radiation (SAXS, WAXS…) will be performed in order to get more insight on how to improve the process. To our knowledge, developing textured nanocomposite thermoelectric ceramics by using the electrospinning technique has not been reported. This project aims at demonstrating the interest of electrospinning coupled with spark plasma sintering process for the design of new functional anisotropic materials with enhanced properties, by creating a texturing at a submicron scale. Although this work will be done on the