Selective Metallization of 3D Printable Thermoplastic Polyurethanes

This paper presents a selective metallization method for the newly developed 3D printable thermoplastic polyurethane elastomers (TPU): FilaFlex
^®
, SemiFlex
^TM
, PolyFlex
^TM
, and NinjaFlex
^®
. Silver nanoparticles were fabricated in-situ by photo-reduction on the surface of TPUs and acted as catalysts for copper ion adsorption. This method demonstrates the successful fabrication of copper patterns on flexible TPU filaments. Furthermore, Polyflex
^TM
and acrylonitrile butadiene styrene (ABS) filaments printed in the same part have been used to enable selective electroless plating directly on PolyflexTMmaterial. Electroless copper deposited onto PolyflexTMhas a sheet resistance of (139.4 ± 7.2) m Ω /□ and a copper conductivity of (1.1 ± 0.1) × 10
⁷
S/m that is comparable with bulk copper. Copper-plated PolyflexTMinterconnects were fabricated as a proof of concept demonstrators.