Scientists have succeeded in attaining precise nano-scale movement that is at least five orders of magnitude faster than previously reported for DNA-driven robotic systems, by powering a DNA nanorobotic arm with electric fields. Their miniscule self-assembling robot could have the potential to work as a platform for new inventions in cargo transfer, digital memory and 3D printing of molecules, states Björn Högberg in a related Perspective.
Nanoscale movement in the natural world, such as the self-assembly of DNA, has aided in inspiring the development of autonomous nanomachines with extensive applications, from biotechnology to computation. However, to depend on DNA's molecular cues to initiate movement in these devices can be an inefficient and slow process, which is the reason why Enzo Kopperger and colleagues employed a different approach for mobilizing their DNA nanorobots: the application of electric fields in a manner that is similar to how electrophoresis moves and then separates huge DNA molecules. With this new power source, Kopperger et al.'s robotic system – made up of a square base and a protruding "arm" all produced from DNA double helices - could point and then rotate in fixed directions at a much greater speed than when depending only on DNA molecular forces. The movement is similar to the gearshift of a car, with single-stranded, short DNA serving as "latches" in order to grab and lock the arm into predefined places. The authors also established their DNA nanorobot's potential for transporting nanoparticles back and forth. The fast, scalable and computer-controlled robotic system can be adapted to comprise of more robotic arms, possibly bringing the research field a step closer to understanding a nanorobotic production factory, the authors say.