This is such an awesome concept and no, I have no idea how it would actually work. Moscow-based designer Igor Lobanov's Sprout pen concept reveals the ink within its clear body in the form of a plant-like sprout. As you use the pen, over time the ink diminishes and the sprout shrinks as if dying.
Too depressing? No worries: When you stick the pen into its inkwell—gotta love that, so old-school—the pen fills with ink, "growing" the sprout.