The first focus at the project start was on defining the design specifications and material requirements for the envisaged demonstrators (additive manufactured robotic joints and luminaires). This was used as basis for establishing the requirements and initial formulations of the novel ink systems and the printing process. During the second half of the project, all directions were pointing at integration and demonstration. Inks and processes were optimized, their interplay to each other investigated and final demonstrators designed and printed. In terms of CE inks different types of ceramic nanoparticles have been synthesized with different particle sizes. Dispersed in UV-curable monomer matrixes, first CE inks were obtained, together with jetting trials, curing strategy and mechanical testing of printed objects. Updated ink formulation with 50% ceramic loading, consequent jetting and curing trials and characterization led to the final semi-printable material showing thermal conductivity up to 2 W/m.K (at 25°C), a Young’s modulus of 1200 MPa and tensile strength of 22 MPa. In terms of EC ink, the set goal in terms of metal content, viscosity, jetting, curing and sintering parameters, shelf life and upscale ability was achieved. The final ink is jetable in several industrial print heads (Ricoh Gen3 E3, E1, Gen4l, KM512), at a frequency of up to 38 kHz. Via subsequent UV curing and NIR treatment within the prototype printer, resistivity of <10 μΩcm was shown, desirable for the DIMAP demonstrators. The HSP based ink development proceeded fast leading to a jetable ink with 80 w% precursor material. A comprehensive study regarding the curing behavior of selected precursors was performed together with jetting, curing and printing experiments and mechanical testing of printed objects. Hence, it was possible to print for the first time thermally stable PI objects by using the PolyJet technology. LWP materials were obtained by using ink systems that are foamable after printing. A proof of concept was obtained for either utilizing core-shell particles and generating open cell foams. The latter approach was favorable, resulting in a long-term stable ink, showing good jet- and printability. Foaming of printed test structures was demonstrated showing the capability of the approach. High strength polymeric and electrically conductive inks entered first a maturity level for investigating their interplay, yielding in functional printed parts of the demonstrators. CE and LWP materials needed a redo and therefore caused a delay in development. However, all 4 materials were shown to be printable in DIMAP prototype printers. Three development versions of the DIMAP prototype printer were constructed, acting as the focal point in Germany, Austria and Israel in the final development phase of DIMAP. Simulation tools and thermography methods supported the integration process for demonstrators. On subsequent designing, based on many iteration steps, we were able show the first PolyJet printed pneumatic robotic arm and printed customized luminaire. Physiochemical properties of manufactured nanomaterials and exposure hotspots were identified with respect to nano-safety. A respective SDS template was created for use by the project partners. No significant release of nanomaterials were detected. Furthermore, DIMAP is partner with the Nanosafety cluster.
