COUNTLESS teenagers have blamed their messy bedrooms on the propensity for everything in the Universe to become increasingly disordered—to have more “entropy”. Now entropy has been persuaded to do some useful work—dragging DNA strands through a microscopic hairbrush.
Steve Turner and his colleagues at Cornell University in Ithaca, New York, built a sandwich of two glass plates with a tiny gap in between (see Graphic). One half of the gap was filled with a forest of pillars that formed long corridors 50 nanometres wide, while the other was left open. They filled the structure with saline solution,…
