Next Generation of 3D‐Printed Electronics: Electroplating Inside Channels to Embed 3D Copper Features within Polymeric Structures Fabricated Through Material Extrusion

Abstract Material Extrusion (MEX) 3D printing has been largely employed to process electrically conductive polymers to fabricate electronic components, which still suffer from bad performance due to high electrical resistance. The electroplating process is proven to drastically reduce the resistance by depositing a thin layer of copper on top of the electrically conductive polymer; however, this method comes with a price to pay: only external features can be plated with copper. The present research paper presents an innovative solution to overcome this issue by performing electroplating inside 3D‐printed parts to plate internal layers (inaccessible for electroplating purposes with traditional approaches) with copper. Electroplating inside closed channels is performed: a remarkable reduction in electrical resistance of 5 orders of magnitude (from 2300 up to 0.08 Ω) is achieved in internal tracks. The proposed approach has also been implemented “on board” a commercial MEX machine to fabricate an assembly‐free smart structure with a copper sensor completely embedded within dielectric material (improved performance compared to traditional counterpart). Furthermore, the proposed approach is proven to fully plate with copper not only planar tracks but also embedded 3D features such as coils. The present research unlocks the fabrication of assembly‐free functional devices with embedded copper elements by only extruding polymers through MEX Additive Manufacturing.