Hydrogels are jelly-like materials made mostly of water with large, filamentous molecules holding it together. On removing water from the DNA hydrogel it collapses and behaves like a liquid. It’s the floppiest gel ever made. But it can be shaped and when water is added it returns to the shape give it. In cycles of collapse and regrowth it always returns to the original shape. The researchers demonstrated this by writing its own name in the hydrogel and letting the letters reform form the “liquid” state.
Practical DNA technologies are under development, such as drug delivery systems, but for now the substance is wowing us all over again, as a purely technical material.
Nature Nanotechnology, 2012, 7, 816-820.