A group of researchers from four American universities have created a 4 nanometer "robot" that can follow a path layed out with DNA. The body of the robot is made out of a common protein called streptavidin. Each of the robot's four legs is a short biotin-labeled strand of DNA.
Once released using a DNA trigger strand, the robot follows a predetermined DNA track by binding to and then cutting the DNA strands extending off the molecular track. Commands for the robot, such as start, walk, turn left, turn right, or stop, are contained in the DNA track itself.
Ultimately, the researchers imagine developing molecular-scale reconfigurable robots for medical applications, such as repairing damaged tissues. However, the future challenges are numerous and for now the group will focus on adding a second robot and study simple communication and cooperation to understand how they may be able to program higher-level behaviors through lower-level interactions.
Science Daily: Spiders at the Nanoscale: Molecules That Behave Like Robots
Original Nature article: Molecular robots guided by prescriptive landscapes