C. Mirkin, Northwestern UniversityLight work. Using a digital micromirror to split beams of light and direct them through apertures in polymer pyramids, Northwestern University researchers drew a variety of molecular architectures and used those to make up the "land" in a map of the world. Imagine trying to draw a maze on something the width of a human hair. Engineers do it all the time when they carve circuits onto semiconductors for our cell phones, tablets, and desktops. That doesn't mean it's easy: The process can require fabrication facilities costing billions of dollars. Now, modifications to an old technique could...