Embedding electronics in 3D printed structures by combining fused filament fabrication and supersonic cluster beam deposition

We present an integrated additive manufacturing approach for the rapid prototyping of objects with embedded electric circuits. Our approach relies on the combined use of standard fused filament fabrication (FFF) for the production of thermoplastic 3D freeform components, and supersonic cluster beam deposition (SCBD) for the fabrication of embedded electrical conducting lines and resistors with tailored conductivity. SCBD is an additive fabrication technique based on the deposition of neutral metallic clusters carried in a highly collimated supersonic beam. SCBD produces strongly adherent conducting layers onto polymeric substrates with electrical resistance depending only on the thickness of the cluster-assembled film. A multi-step fabrication procedure alternating FFF and SCBD was developed and optimized allowing the fabrication of conductive 3D oblique paths, bridging vias, and sockets for standard electronic components fitting. This resulted in the simplification of the topology of planar electric circuits by enabling out-of-plane connections, minimizing the implementation of bulky passive electrical components and avoiding the use of soldering and conductive adhesives for the integration of active electronic components. A dark-activated light sensor was produced as a demonstrator.