Supplementary Data 1-8 STL files of 3D bioprinted tissue constructs. Supplementary data 1: Pocillopora damicornis tissue expanded. Supplementary data 2: STL file of intermediate bionic skeleton. Supplementary data 3: STL file of final simplified skeleton. Supplementary data 4: STL file of final simplified tissue. Supplementary data 5: STL file of skeleton of Pavona cactus. Supplementary data 6: STL file of coenostal spines of Pocillopora damicornis. Supplementary data 7: STL file of tissue surface of Pavona cactus. Supplementary data 8: STL file of tissue surface of Favites flexuosa. See the main manuscript for more details.

Source data Microsoft excel file combining the source data for figures shown in the manuscript. Figure 2: Normalized transmittance data for the angular distribution of forward scattered light (Ø=270–90 º in 1 º increments) at 550 nm for the bionic skeleton and bionic tissue (Figure 2 h). Data was acquired with an optical goniometer. Microprobe-based fluence rate measurements (E0 in % of incident irradiance) for the bionic coral (Figure 2 i) and a flat slab of GelMA (Figure 2 j) both with a microalgal density of 5.0 x 106 cells mL-1. Column A shows nanometer (wavelength) and column B-G show tissue depth in micrometer. Data was acquired with fiber-optic scalar irradiance microsensors and operated by an automated micromanipulator. See the main manuscript for more details. Figure 3: Growth of Marinichlorella kaistiae KAS603 in bionic coral (Figure 3a). Column A represents experimental days, Column B represent 3d printed replicates, Column C represents cell density (cells mL-1). Vertical attenuation of fluence rate (E0 at 675 nm) at the beginning (day 1) and end of the performance test (day 12, Figure 3b). Column A shows nanometer (wavelength) and column B-G show tissue depth in micrometer. Data was acquired with fiber-optic scalar irradiance microsensors and operated by an automated micromanipulator. Raw O2 profiles (Figure 3c profiles) generating net photosynthetic rates (Figure 3c flux) of the bionic coral prints at day 5, 8 and 11. Profiles were generated with electrochemical O2 microsensors and flux was calculated according to Fick’s fist law of diffusion. Column A represents experimental data, column B represents incident downwelling irradiance, Column C represents O2 flux in nmol O2 cm-2 s-1L. Experimental curve fits were performed using the Webb equation (Figure 3c Webb fit) showing the maximum photosynthetic rate (Pm), the light use efficiency (alpha) and R2 values. Volumetric photosynthetic rates (Figure 3d) measurements were performed with O2 microsensors at the center of the corallite cup surface (labelled surface) and at a vertical depth of 300 µm (labelled depth). Photosynthetic rates are expressed as nmol O2 cm-3 s-1. See the main manuscript for more details. Supplementary Figure 2: Total transmittance of bionic skeleton with 7% CNC concentration for different slab thicknesses (1-4.5 mm) per wavelength (wl) in nanometer (Supplementary Figure 2a). Total transmittance of bionic coral tissue doped with different concentrations of CNC (0-2%) (Supplementary Figure 2b). Fitting of extrapolation length (ze) for bionic skeleton according to Eq. 2 in the manuscript based on the angular distribution of transmitted light (Supplementary Figure 2c). Calculated transport mean free path (lt, µm) (Supplementary Figure 2d) and absorption length (la, mm) for bionic skeleton (Supplementary Figure 2e). Extinction length for bionic tissue estimated using Beer-Lambert law (Supplementary Figure 2f). Effect of CNC doping and corallite cup size on fluence rate (E0) attenuation. Measurements were performed for different CNC concentrations (0-10%) using the original corallite cup size (maximal width = 1 mm) and a 1.5-fold enhanced size (Supplementary Figure 3). E0 (fluence rate) was normalized to the vertically incident downwelling irradiance Ed. Supplementary Figure 5: Stress-strain analysis of coral-inspired bionic tissue. Replicate measurements of 6 bionic tissues were performed. The average elastic modulus was E = 4.3 kPa. See the main manuscript for more details.