Micro-component manufacturing via Vat Photopolymerization Processes (VPP)

The feasibility and reliability of Additive manufacturing (AM) technologies have already been demonstrated for fabricating micro components. In this work, the vat photopolymerization process (VPP) capabilities are investigated, fabricating an artifact with challenging micro-features, i.e., micro-pins and holes with different shapes and aspect ratios, having dimensions in the range of 0.02-2 mm and heights/depths of 0.5-1.5 mm. Two VPP processes, namely SLA and DLP, were selected for the comparison, and a Formlabs photosensitive resin, Grey V02, was used for the fabrication. The main printing parameters were fixed for both SLA and DLP: layer thickness 25 μm, part orientation flat on the build platform, no supports, and the same post-processing tasks to minimize their influence on final results. Results revealed that SLA is capable of a higher feature resolution. The smallest fabricated pins have 0.2 and 0.4 mm sizes for SLA and DLP, respectively. DLP is characterized by distortion effects of the projected light far from the center of the build plane. For both technologies, errors in pin heights are comparable (-60 μm). SLA is more accurate with circular pins, while DLP is with squared pins.