Hydrogel remembers its shape -- just add water

Scientists have created a shape-remembering material out of synthetic DNA that is eerily reminiscent of T-1000, the liquid metal assassin in the hit sci-fi film Terminator 2. The material is a new kind of hydrogel, a mesh of organic molecules with many empty spaces that can absorb water like a sponge. Hydrogels are found everywhere from self-healing contact lenses to an instrument on a NASA spacecraft that gathered flecks of comet dust.