Scientists have figured out how independent, programmable nano-scale robots can be made out of individual molecules—with the robots’ actions programmed into their environment. “Both studies fuse two of the most interesting advances in nanotechnology: the design of DNA machines, fashioned from life’s essential double helix and possessing the ability to walk about; and the invention of DNA origami, where sets of specially constructed DNA molecules can be fused together into beautiful sheets and sculptures. Combine the two and you get a robot walker and a track for it to walk upon.”