Additively Manufactured Electronic Circuits from Polymer Pastes

The aim of this work was to characterize an electrically conductive polymer pastes based on polystyrene, or poly(vinyl acetate) with graphite filler that can be utilized for syringe-based 3D printing. This work is based on previous research, which demonstrated the electrical conductivity of the polystyrene paste sufficient for the use in electronics. Rheological properties, including frequency and amplitude sweeps, were studied in this work. Loss tangent remains low (close to 1) for both pastes at low oscillation strains, however it increases at higher values which indicates that low printing speeds are needed to obtain objects that retains its shape. The presented composite pastes can be used to print conduits or electrodes. No soldering is required as the pins of other individual components (such as connectors or LEDs) can be inserted directly into the paste after the printing process. Products are then left at room temperature to fully solidify. The demonstrating circuit with LED was prepared by this method and its functionality was successfully verified. An electrode was printed from each paste and water electrolysis was successfully performed. The performed proof-ofconcept experiments show feasibility of printing conductive structures from the presented materials.