3D Printing Electronic Components And Circuits With Conductive Thermoplastic Filament

This work examines the use of dual-material fused filament fabrication for 3D printing electronic components
and circuits with conductive thermoplastic filaments. The resistivity of traces printed from
conductive thermoplastic filaments made with carbon-black, graphene, and copper as conductive fillers
was found to be 12, 0.78, and 0.014 ohm cm, respectively, enabling the creation of resistors with values
spanning 3 orders of magnitude. The carbon black and graphene filaments were brittle and fractured
easily, but the copper-based filament could be bent at least 500 times with little change in its resistance.
Impedance measurements made on the thermoplastic filaments demonstrate that the copper-based filament
had an impedance similar to a copper PCB trace at frequencies greater than 1 MHz. Dual material
3D printing was used to fabricate a variety of inductors and capacitors with properties that could be
predictably tuned by modifying either the geometry of the components, or the materials used to fabricate
the components. These resistors, capacitors, and inductors were combined to create a fully 3D
printed high-pass filter with properties comparable to its conventional counterparts. The relatively low
impedance of the copper-based filament enabled its use for 3D printing of a receiver coil for wireless
power transfer. We also demonstrate the ability to embed and connect surface mounted components in
3D printed objects with a low-cost ($1000 in parts), open source dual-material 3D printer. This work thus
demonstrates the potential for FFF 3D printing to create complex, three-dimensional circuits composed
of either embedded or fully-printed electronic components.