A team of researchers at Cornell University, led by professor Dan Luo, has developed a new kind of hydrogel made from synthesized and interwoven DNA, like a microscopic bird's nest. In the presence of H2O the hydrogel forms and holds a pre-determined shape. But in the absence of water, the material flows like any other liquid. If that sounds familiar, you've probably seen Terminator 2.
The researchers aren't entirely sure why the material behaves this way just yet, but they think that the forces responsible for holding its shape are so weak that surface tension and gravity are enough to cause it to collapse. But when under water there's enough buoyancy to cancel out the effects of gravity, and negate the surface tension forces.
The practical uses of the new material immediately conjure up images of the menacing T-1000 from T2. But unless John Connor is hiding in a pool, he hasn't much to fear. As a more realistic application, the researchers were able to create a working electric circuit that uses water as a switch. And safety gear that forms a supportive frame or craft when someone goes overboard isn't that much of a stretch either. [Nature Nanotechnology via PhysOrg]