Steady progress in structural DNA nanotechnology over the past several years has seen the improvement of DNA machines that walk along DNA tracks as harbingers of future molecular assembly lines. For the two most recent posts here, see “DNA nanorobot walks without intervention along rigid track” and “DNA-based ‘robotic’ assembly begins” Another step towards DNA-based molecular assembly is reported by nanotechweb.org, written by Belle Dumé “Nanobots move on” (requires free registration):
A team of physicists at the University of Oxford in the UK has designed a molecular robot that can be programmed to move in any direction along a branched track. Such control was not possible until now because previous devices were only able to move forwards in a straight line. The robot might find use in nanotechnology applications such as next-generation molecular machines and be used to move “cargo”, like drugs.
Researchers recently succeeded in building a molecular motor that “walks” in a single direction instead of wandering about randomly. This feat was already a breakthrough because it was difficult to coordinate the movement of the motor’s two “legs” so that they moved in a synchronized way without the legs coming off a predefined track.
Now, Andrew Turberfield’s team at Oxford has gone a step further by designing a nanorobot, or nanobot, that can be made to move in any direction along the track, as well as backwards and forwards. In contrast to previous bipedal motors, the new device only has one leg (made of synthetic DNA) anchored to a nanoscale track made of a double-stranded DNA backbone. The robot walks by taking tiny steps that involve its leg tethering and untethering to the DNA backbone and the machine is powered by different “fuel” DNA strands that push it along.
Spurred on by these new results, the team would now like to move the motor over longer tracks. “Using concepts and mechanisms developed in this research, we would also like to coordinate assembly of a chemical product, where a nanorobot moves between locations and picks up ingredients in a reaction,” added Muscat. “This would be a nanoscale production line.”
The results were described in Nano Letters [abstract].