#3DStartup: Kupros’ Cu29: A Conductive Copper Filament for FDM Electronics an Expert Said Would “Never Be 3D Printed”

When Ian Ramsdell, founder of Kupros, started asking electronics specialists about 3D printing copper, he faced plenty of skepticism. One expert, in Ramsdell’s recollection, insisted it could not be done and never would be: “Copper can’t be 3D printed, it’ll never be 3D printed.” What that expert did not know was that Ramsdell was already working from a confirmed laboratory experiment, one the US military had run and validated years earlier.

That distance between “impossible” and “already proven in a lab” is the founding story of Kupros and its flagship product, Cu29: a fully metallic, conductive filament engineered to print on standard fused deposition modeling (FDM) machines. Cu29 is not solid copper, but an all-metal, conductive filament that uses copper as part of the formulation. Because the conductor is extruded alongside structural plastic in the same build, Cu29 is aimed at integrated sensors, embedded signal routing, and conformal antennas and conductive paths that follow a part’s geometry rather than sitting on a flat board.

Cu29 can be used to develop embedded electronics.

In aerospace and defense, where Kupros sees its strongest early demand, the pitch is concrete: fewer wiring harnesses, connectors and interconnects, structural-health sensing built into load-bearing parts, and faster iteration as electrical and mechanical design evolve together. “Just because somebody has been told that something is impossible, doesn’t mean it can’t be done,” Ramsdell said.