In this study we employ the 3 dimensional (3D) printing technology, in order to fabricate large scale 3D structures, dedicated for energy and environmental applications. 

Lately, 3D printing technology has gained a lot of interest in various research fields, such as medicine, chemistry and materials science, as an alternative, trendy and effective route for production of 3D printed samples. There are plenty of commercially available polymer-based filaments, but there is a lack of conductive, magnetic, photocatalytic flexible filaments, to name but  a few. Thus, it becomes prudent to produce custom-made filaments, containing nanometer or micrometer sized materials with dedicated properties. Considering that the nanoparticles keep their properties unaffected, after the blending with the polymer matrix the produced filament could exhibit corresponding functionalities.

Considering the above, we fabricate 3D polymeric nanocomposite structures, using Acrylonitrile butadiene styrene (ABS), Polylactide (PLA) filaments, enriched with metals or various carbon structures, namely graphite nanofillers, carbon nanotubes and graphene oxide nanosheets, and we study them regarding their electromagnetic shielding efficiency in the C-band of the electromagnetic spectrum (3.5–7.0 GHz), which is typically used for long-distance radio telecommunications. Through this study, it is evidentl that 3D printing technology can be effectively used to prepare operational shields, for electronic device applications.

Moreover, we fabricate a number of conductive Spilt Ring Resonator (SRRs) metamaterial units, in a free-standing form, using Polyvinylidene chloride (PVDC) matrix, in which copper (Cu) nanoparticles are included. We experimentally characterize the samples through transmission measurements conducted in standard rectangular waveguide configurations. The structures exhibit well defined resonant features dependent on the geometrical parameters and the infiltrating dielectric materials. Thus, the flexible and light metasurfaces may serve as electromagnetic components and fabrics for coating a plethora of devices and infrastructure units of different shapes and size. For example, they can be used in sensing configurations, microwave antennas, waveguides, couplers, absorbers, filters, harvesters.

Finally, we fabricate polymeric nanocomposite filaments, consisting of ABS, PS, LDPE, and ZnO or TiO₂ nanoparticles in order to construct 3D printed photocatalytic structures against dyes or drug residues. The produced structures exhibit high photocatalytic efficiency after several cycles of use, under UV irradiation. Thus, it is evidently shown that 3D nanocomposite structures show promising photocatalytic properties, for potential real – life environmental applications.