Towards additive manufacturing of flexible thermoelectric energy harvesters: boosting the performance by laser sintering-induced nanostructuring

Thermoelectrics (TEs) can harvest electrical energy from waste heat, contributing to reducing our carbon footprint. They can also enable active heating and cooling. However, the high cost/efficiency ratio of current TEs is hindering their widespread use. To increase the efficiency of TEs, materials with high electrical/low thermal conductivity are necessary. Micro/nanostructure influences each conductivity in a different way, opening an opportunity to optimize the TE performance. Indeed, porous, polycrystalline and anisotropic TE materials hold promise to boost the performance along a preferential direction by dramatically reducing the thermal conductivity without significantly degrading the electrical conductivity. In this project, we propose the development of flexible inorganic TE parts with controllable morphology achieved by selective laser sintering of binder/TE nanopowder composite slurries blade-coated on plastic foil. The thermal/electrical conductivity and Seebeck coefficient of the printed materials will be correlated with their morphology along different directions. Porosity and texture will be sought in order to optimize their TE performance. Furthermore, the use of additive manufacturing (AM) will allow us the fabrication of the parts on flexible substrates, paving the way to large-area and flexible TE generators. These features, along with the low-cost character of AM will expand the usability of TE devices far beyond their traditional applications.

Keywords:Thermoelectrics, Transport properties, Selective laser sintering, Flexible electronics, 3D printing

Disciplines:Functional materials, Materials processing, Energy conversion, Microfabrication and manufacturing, Electronic (transport) properties, Nonelectronic and thermal transport properties