A 3D printable diamond polymer composite: a novel material for fabrication of low cost thermally conducting devices

The development of a thermally conducting composite material that can be rapidly 3D printed into prototype objects is presented. The composite structures containing 10, 20, 25 and 30% (w/v) of 2-4 micron sized synthetic diamond microparticles added to the acrylate polymer were produced using a low cost stereolithographic 3D printer. The prepared materials were characterised according to heat transfer rates, thermal expansion co-efficients and contact angles, and analysed using high resolution electron microscopy, thermogravimetric analysis and thermal imaging. The composites displayed minor enhancements in heat transfer rates with incrementing diamond content upto 25% (w/v), however a significant improvement was observed for the 30% (w/v) polymer-diamond composite, based on an interconnected diamond aggregate network, as confirmed by high resolution scanning electron microscopy. The developed material was used in the fabrication of prototype 3D printed heat sinks and cooling coils for thermal management applications in electronic and fluidic devices. Infrared thermal imaging performed on 3D printed objects verified the superior performance of the composite compared to the inherent polymer.