Extended Data Fig. 3: 3D printing with UCNCs.

a, Formlabs print simulation of the same Benchy STL. The file was imported into the free software PreForm 3.18.0 and simulated for printing on a Form 3B printer at 50-μm layer height. The boat was scaled to match the dimensions of the Benchy printed on our printer. The boat, without support structures, required 200 layers and 0.14 ml of resin. At this point, we used the ‘one-click-print’ function to generate the printable structure with support structure. This resulted in an object with 289 layers at 50-μm layer height, using 0.85 ml of resin. The STL file image (b) and a photograph (c) of the Harvard University logo presented in Supplementary Video 3. The Harvard University logo presented here was printed using a different resin formulation with bis(5-2,4-cylcopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl) titanium (titanocene, Gelest) as a photoinitiator instead of Ivocerin. This resin was prepared with 1.9 wt% Aerosil 200, 3 wt% titanocene, 13 wt% Br-TIPS-anthracene capsules, 0.03 wt% Sudan I and 5 ppm TEMPO. This resin formulation limited printing resolution,hence the emphasis on the use of the resin presented in the main text and Methods. d–f Side-by-side comparisons of the STL file schematic to the corresponding Benchy photograph from the same perspective. The boats presented in panels d-f were printed using the resin formulation described in the Methods section. g, A representative image of a gear under the microscope shows that round and straight features are generally smooth. The images were taken after washing away excess resin and allowing the gear to dry under an ambient atmosphere in the dark. h, An overprinted boat gives a lack of discernable features. i, An underprinted boat shows missing features and damage from the wash process. Both issues are remedied by altering the print speed and irradiation power. The boats presented here were printed using the same resin formulation as the Harvard University logo presented in panel c.