Scientists invent DNA robots.

What could go wrong? From Technology Review:

Its precise structure and ability to bind with other molecules makes DNA an attractive scaffolding material for nanotech researchers. Scientists have already used DNA to construct two-dimensional patterns, three-dimensional objects, and simple shape-changing devices. Now two teams of researchers have separately made complex programmable machines using DNA molecules.

Researchers from Columbia University, Arizona State University, and Caltech have made a device that follows a programmable path on a surface patterned with DNA. Meanwhile, researchers from New York University, led by DNA nanoarchitecture pioneer Ned Seeman, have combined multiple DNA devices to make an assembly line. The nano contraption picks up gold nanoparticles as it tumbles along a DNA-patterned surface.

The two machines, described in today's Nature journal, are a possible step forward in making DNA nanobots that could assemble tiny electrical and mechanical devices. DNA robots could also put together molecules in new ways to make new materials, says Lloyd Smith, a chemistry professor at the University of Wisconsin-Madison. "Robots might have the ability to position one molecule in a particular way so that a reaction happens with another molecule which might not happen if they randomly collide in solution," he says.