Rotary 3D Printing With Integrated Electroplating

Material extrusion additive manufacturing enables structural and conductive materials to be integrated within a single component; however, the limited conductance of conductive polymers restricts their functional performance. Electroplating can improve conductance, but conventional post‐processing approaches cannot create fully embedded metallic features. In addition, in situ electroplating for rotary additive manufacturing of cylindrical structures remains largely unexplored. This work presents a rotary hybrid polymer–metal additive manufacturing process that integrates localized copper electroplating directly into a mandrel‐based material extrusion platform. A custom electroplating head, automated electrolyte delivery system, and dedicated G‐code framework were developed to synchronize printing, metallization, and encapsulation within a single workflow. Conductive PLA tracks were selectively metallized through a voxel‐by‐voxel deposition strategy and subsequently embedded within dielectric PLA. Under optimized conditions, corresponding to 66% voxel overlap and two electroplating passes, track resistance decreased from approximately 2300 to 0.1 Ω, corresponding to a conductance enhancement factor of about 23 000. Microstructural analyses showed that copper deposition bridges filament interfaces and forms continuous metallic pathways. The embedded copper networks were further used as internal electrothermal elements to activate shape‐memory responses in auxetic and spring structures, enabling monolithic cylindrical polymer–metal architectures with integrated electrical, thermal, and actuation functionalities.