A team of scientists from Columbia University, Arizona State University, the University of Michigan, and the California Institute of Technology (Caltech) have programmed an autonomous molecular "robot" made out of DNA to start, move, turn, and stop while following a DNA track.Here's how the same fact gets written up in a popular science magazine, Discover:
The development could ultimately lead to molecular systems that might one day be used for medical therapeutic devices and molecular-scale reconfigurable robots—robots made of many simple units that can reposition or even rebuild themselves to accomplish different tasks.
A paper describing the work appears in the current issue of the journal Nature.
Shrinking robots down to the molecular scale would provide, for molecular processes, the same kinds of benefits that classical robotics and automation provide at the macroscopic scale. Molecular robots, in theory, could be programmed to sense their environment (say, the presence of disease markers on a cell), make a decision (that the cell is cancerous and needs to be neutralized), and act on that decision (deliver a cargo of cancer-killing drugs).
Or, like the robots in a modern-day factory, they could be programmed to assemble complex molecular products. The power of robotics lies in the fact that once programmed, the robots can carry out their tasks autonomously, without further human intervention.
Two spiders are walking along a track – a seemingly ordinary scene, but these are no ordinary spiders. They are molecular robots and they, like the tracks they stride over, are fashioned from DNA. One of them has four legs and marches over its DNA landscape, turning and stopping with no controls from its human creators. The other has four legs and three arms – it walks along a miniature assembly line, picking up three pieces of cargo from loading machines (also made of DNA) and attaching them to itself. All of this is happening at the nanometre scale, far beyond what the naked eye can discern. Welcome to the exciting future of nanotechnology.This is interesting because it is the first indication of new technology. Like all initial new technology it appears a bit limited and it is hard to envision fully the revolution hinted at by the new capability. In this case they talk about drug deliver. Most likely that will be a very small niche opened up by this new technology, but the inventors are struggling to perceive where their invention is heading. That is quite normal.
The two robots are the stars of two new papers that describe the latest advances in making independent, programmable nano-scale robots out of individual molecules. Such creations have featured in science-fiction stories for decades, from Michael Crichton’s Prey to Red Dwarf, but in reality, there are many barriers to creating such machines. For a start, big robots can be loaded with masses of software that guides their actions – no such luck at the nano-level.
The two new studies have solved this problem by programming the robots’ actions into their environment rather than their bodies. Standing on the shoulders of giants, both studies fuse two of the most interesting advances in nanotechnology: the design of DNA machines, fashioned from life’s essential double helix and possessing the ability to walk about; and the invention of DNA origami, where sets of specially constructed DNA molecules can be fused together into beautiful sheets and sculptures. Combine the two and you get a robot walker and a track for it to walk upon.
Now this is impressive – in a related editorial, Lloyd Smith from the University of Wisconsin says, “This is the first time that systems of nanomachines, rather than individual devices, have been used to perform operations, constituting a crucial advance in the evolution of DNA nanotechnology.”
Neither robot quite scales the heady heights of science-fiction nanotechnology. One is autonomous but simple, while the other is complex but requires much in the way of human intervention. And both are quite limited in the things that they can do. But these robots are taking tiny but important steps towards greater things. They are a sign that the field of nanotechnology is set for great strides in the future.