A novel method for 3D printing high conductivity alloys for UHF applications

Traditional approaches to constructing 3D structural electronics with conductive and dielectric materials include ink-jet printed, silver-bearing ink and fine copper wire meshes. One approach combines stereo-lithographic 3D-printed photo-polymers with direct-printed silver-bearing conductive inks. Results have shown 3D conductive structures with conductivities in the range 2 x 10⁶ to 1 x 10⁷ S/m using annealing temperatures ranging from 110°C to 150°C for 10 to 15 minutes. However, the stereo-lithographic approach suffers from the high cost of the printer and structural deformation during annealing. This paper presents a new method for 3d printing high conductivity metal alloys using consumer-grade 3D printer. The design and construction of the necessary modification will be presented in addition to the new 3D design process. The method yields metal structures with expected conductivities exceeding 2.6 x 10⁶ S/m. The process is performed without an annealing step, so the polymeric structural material is not exposed to high temperatures for any prolonged time. A UHF ISM band antenna is constructed for an RFID application using this method, the antenna performance is measured, and the results are compared simulations in Ansys HFSS. This new method can reduce total cost, and several low melting-point alloys could raise the conductivity.