In a proof-of-concept study published in the Journal of Materials Science, researchers demonstrated a direct and spatially selective electroless copper-plating strategy on three-dimensionally printed polylactic acid and iron composites. The approach utilizes commercially available metal-filled polylactic acid filaments to introduce functional metallic surface properties while preserving the geometric design freedom inherent to additive manufacturing.

To prepare the printed composite surfaces for plating, the researchers developed an activation procedure that combined 800-grit mechanical abrasion with alkaline etching. This mechanical and chemical treatment exposed embedded iron particles that were previously enclosed within the printed polymer matrix at the component surface.

The exposed metallic iron particles are proposed to serve as intrinsic catalytic sites that facilitate direct copper nucleation during the deposition process. By relying on these exposed particles, the experimental procedure successfully bypasses conventional, multi-step noble-metal activation processes, such as traditional palladium and tin sensitization baths.

Spatial selectivity across the printed part was achieved by applying a superhydrophobic masking coating to regions intended to remain unplated. The protective mask combined octadecyltrichlorosilane with silicon dioxide nanoparticles, pairing nanoscale roughness with low surface energy to yield a measured water contact angle of 167 ± 5 degrees on masked surfaces.

Material characterization using scanning electron microscopy and energy-dispersive X-ray spectroscopy confirmed successful copper deposition exclusively across the activated, unmasked surface regions. Under the investigated plating conditions, the researchers observed that the most homogeneous copper surface morphology developed after three hours of electroless deposition.

The metallic deposition resulted in a substantial transformation of the material’s electrical characteristics. Prior to treatment, the as-printed polylactic acid and iron composite exhibited an electrical conductivity of approximately 1.2 × 10−15 siemens per meter, which increased to approximately 15 × 102 siemens per meter following electroless copper deposition.

The authors emphasized that their work establishes a preliminary proof of concept, noting several critical engineering parameters that were not measured during the investigation. Specifically, sheet and surface resistance as a function of plating duration, coating thickness, standardized adhesion strength, quantitative pattern fidelity, and electromagnetic-shielding performance remain unquantified and are identified as necessary requirements for future validation.

Subject of Research: Selective electroless copper plating on 3D-printed iron composites

Article Title: Direct selective electroless copper plating of 3D-printed PLA/Iron composites via superhydrophobic masking

Article References: Pandit, S. K., Dong, Y., Pramanik, A., & Kumar, A. (2026). Direct selective electroless copper plating of 3D-printed PLA/Iron composites via superhydrophobic masking. Journal of Materials Science. https://doi.org/10.1007/s10853-026-13920-4

Image Credits: AI Generated

DOI: 10.1007/s10853-026-13920-4

Keywords: electroless copper plating, 3D-printed composites, PLA/iron composites, superhydrophobic masking, surface activation, alkaline etching, mechanical abrasion, iron particles, copper nucleation, noble-metal-free metallization, octadecyltrichlorosilane, silicon dioxide nanoparticles, water contact angle, electrical conductivity, additive manufacturing, energy dispersive X-ray spectroscopy, scanning electron microscopy