A new kind of molecular motor constructed from DNA could lead to future designs capable of performing a range of a complex tasks, including drug delivery, manufacturing and chemical processing.

Writing in the journal Nature Nanotechnology, the researchers say they were able to use their invention to transport a nanoparticle down the length of a carbon nanotube.

The tiny device is comprised of a core and two arms - one above the core and the other below. As it travels the length of the tube, it gathers energy from strands of RNA.

"Our motors extract chemical energy from RNA molecules decorated on the nanotubes and use that energy to fuel autonomous walking along the carbon nanotube track," study co-author Jong Hyun Choi, an assistant professor of mechanical engineering at Purdue University.

The scientists used two fluorescent imaging systems to track the motor's movement - one in the near-infrared

Inspiration for the motor came from natural biological motors made of protein that have evolved to perform tasks needed to keep cells working, according to Choi.

Both kinds - natural and synthetic - have their pros and cons. For example, while the synthetic motors are much slower than their natural counterparts (it took the motor 20 hours to reach the end of the several-micron-long nanotube), the natural motors cannot be controlled and cease to function as soon as they are taken out of their environment. DNA motors, in contrast, are more stable and capable of switching being switched on and off.

The researchers believe the motor might be sped up by shifting the temperature and pH around. Either way, the motor is something of a first draft for the scientists.

"We are in the very early stages of developing these kinds of synthetic molecular motors," Choi said.

The US Office of Naval Research funded the study.