From Composite Filaments to Low-loss Circuits: A Novel Hybrid Manufacturing Approach to 3D-Printed Electronics

Electrically conductive filaments have shifted the paradigm of 2D circuitry towards 3D-printed electronics by enabling rapid prototyping of complex, embedded circuits. Despite being limited to low-current applications due to ohmic losses from their composite structure, the involvement of a user is kept at a minimum. Selective immersion-based electroplating addresses this limitation but is constrained to specific design spaces and requires human intervention. This study explores the concept and novelty of a proposed hybrid manufacturing system based on 3D printing followed by electroplating, addressing the limitations of traditional immersion-based methods. Moreover, both processes are performed on the same machine - a modified Prusa i3 MK3S+, paving the way towards sequential and human-independent hybrid manufacturing. Thusly 3D printed and electroplated samples were validated in terms of coating quality and their subsequent electrical resistance. The conductivity of commercially available copper-infused polymer filament was locally increased by two orders of magnitude through the proposed approach. Additionally, microscopy was used to characterize homogeneity. As a functional demonstrator, an electromagnetic acoustic transducer of 7.3 Ω resistance was successfully manufactured and tested, highlighting the practical applicability of the proposed method. Selective cup-based electroplating of 3D-printed electronics therefore announces its potential as a human-independent process within low-loss circuitry, while employing the full design-space flexibility of additive manufacturing.