Next, the printability window was inves gated by prin ng arrays of cylindrical pillars (diameter = 10 µm, z-height = 10 µm) with varying laser power intensity from 10 to 25 mW as well as varying laser scan speed from 6000 to 20000 µm s -1 . The printed microstructures were characterized a erwards by scanning electron microscopy (SEM) imaging (Figure ). Both microalgae-based inks present similar printability windows (green labelling in Figure ). Too low energy doses (scan speeds above 14000 µm s -1 at a laser power of 10 mW for O. aurita-based inks, and scan speeds above 18000 µm s -1 at a laser power of 10 mW for T. striata-based inks) led to incomplete prin ng of the pillars due to poor network forma on and low crosslinking degree. However, if the energy dose is above a certain threshold (scan speeds below 8000 µm s -1 and 6000 µm s -1 at laser powers above 20 mW and 25 mW respec vely for O. aurita-based inks, and scan speeds below 12000 µm s -1 , 8000 µm s -1 and 6000 µm s -1 at laser powers above 15 mW, 20 mW and 25 mW respec vely for T. striata-based inks), micro-explosions start to occur. The parameters that led to insufficient or not sa sfactory prin ng quality are labelled in red and yellow, respec vely, in Figure . However, both microalgae-based inks present a broad printability window (green labelling in Figure ).