Fig. 4. Particles fabricated via r2rCLIP enable a range of applications including ceramic particles and drug delivery.

a, Hollow ceramic cubes formed from pyrolysis of HDDA–ceramic mix resin. b, EDS analysis of the surface of a hollow ceramic cube (top left) showing uniform distribution of silicon and oxygen, quantified as 30 ± 1% silicon, 35 ± 1% oxygen and 35 ± 2% carbon by normalized mass. Elemental distribution of O, Si and C (top right, bottom left and bottom right, respectively) overlaid on secondary electron image of the hollow cubes. c,d, Drug-delivery cubes may be designed to meet the goals of payload volume, release profile, material and so on (c) and fabricated via r2rCLIP (d) (PEGDMA₅₅₀ material, for example). e,f, Devices may be then filled, as demonstrated with trypan blue dye for visualization (e), and subsequently capped (f). Scale bars, 100 µm (a), 5 µm (b, top left), 100 µm (b, other three images), 3 mm (d,e), 200 µm (f).