While the advancement on its own is a sophisticated display of science, such technology could be used for a wide range of applications; for example, these robots could be used to assemble chemical compounds, or to rearrange nanoparticles on circuits.
To create the robot, Anupama J. Thubagere and her colleagues in the laboratory of Lulu Qian, assistant professor of bioengineering at Caltech, assembled various strands of DNA, which include one "leg" that sprouts two feet, and two arms that carry a piece of cargo.
The robot moves along 2-D tracks of DNA origami. Only one foot can be anchored to a track at a given time; therefore as one foot steps down on the track, the other becomes free. The robot walks along the track until it encounters the object it's designed to carry, in this case a fluorescent molecule or a DNA strand that binds to the robot's arms. The robot then continues to move along the track until it encounters a goal strand of DNA.
The researchers designed the goal strand to automatically snatch the cargo from the robot. The robot is then free to explore other locations on the origami surface and pick up another piece of cargo it encounters.
"Though we demonstrated a robot for this specific task, the same system design can be generalized to work with dozens of types of cargos at any arbitrary initial location on the surface," said Thubagere. "One could also have multiple robots performing diverse sorting tasks in parallel."
The robot successfully sorted six scattered molecules, three pink and three yellow, into their correct places in 24 hours. Adding more robots to the surface shortened the time it took to complete the task.
The research is published in the journal Science under the title “A cargo-sorting DNA robot.”
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