Fourier-transform infrared spectroscopy (FTIR) was conducted in the case of microalgae-based extracts and inks ("liquid" species) on a Jasco FT/IR-4600 FT-IR spectrometer in ATR mode with a resolu on of 1 cm -1 and 32 scans. In the case of the 3D printed microstructures ("solid" species), infrared spectra were taken using Bruker LUMOS II FTIR microscope in ATR mode with a resolu on of 4 cm -1 and 64 scans using a LN-MCT Mid detector (liquid N2 cooled).