Upon ablation from the channel walls, the formed alginate gel maintains its shape as it leaves the device. Figure shows microscopic images of gels eluted during flow tests performed at chemical conditions of C Alg =0.1mg/mL and C Ca 2+ = 100mM and a 1:1 flow rate ratio, Q Alg = Q Ca 2+ = 2µL/min. After elution and collection, which includes removal from the end of the channel by pipette, the gel rods maintain their shape as formed in the channel. The eight rods in Figure vary in length between 400 and 900 µm, with an average length of 650µm. Their width is ∼ 30µm, giving them an average aspect ratio of 22:1. The rods are stable in a 100mM calcium chloride solution for at least several weeks: they neither aggregate, disintegrate, nor change shape. They even maintain their shape upon pipetting to remove them from the channel exit. At this chemical composition, similar gels form at all other flow rate ratios investigated (see SI . However, rods are formed most reliably during flow tests in which the intermittency behavior is slowest. As ablation frequency increases, the resulting rods become shorter and more globular.