Exponetially self

The team of researchers was formed from a collaboration of scientists from New York University, the Ningbo CixiInstitute of Biomechanical Engineering, and The Chinese Academy of Sciences. Together, they developed nanorobots capable of assembling pieces into three-dimensional shapes. This significantly improved over previous attempts, which could only create two-dimensional shapes. The new robots use "multiple-axis precise folding and positioning" to access the third dimension and more degrees of freedom.

"By making use of externally controlled temperature and ultraviolet (UV) light, our programmable robot, ~100 nanometers in size, grabs different parts, positions and aligns them so that they can be welded, releases the construct, and returns to its original configuration ready for its next operation," the team explains in their study published in Science Robotics. "Our robot can also self-replicate its 3D structure and functions, surpassing single-step templating (restricted to two dimensions) by using folding to access the third dimension and more degrees of freedom," they add.

So what's the big deal? Well, nanobots like these have the potential to manufacture drugs, enzymes, and other chemicals inside the cells of the body. The researchers emphasized that these machines can self-replicate their entire 3D structure and functions.

Andrew Surman, a researcher at King's College London who was not involved in the study, believes that nanobots represent a significant advancement in developing DNA-based machines capable of manufacturing drugs or chemicals and serving as basic robots or computers. Prior research has been limited to 2D shapes that had to be folded into 3D shapes, which carried the risk of error. However, the new research enables the creation of 3D structures from scratch.

But, it is important to note that the DNA bots are not entirely self-contained. The robots act in response to externally controlled temperature and UV light. UV light is required to weld the pieces of DNA they assemble. "Our introduction of multiple-axis precise folding and positioning as a tool/technology for nanomanufacturing will open the door to more complex and useful nano- and microdevices," the team explains in their paper.

"Gray Goo Scenario"

It is all very exciting, but some raise concerns about such technology if developed unchecked and without limits. This is something called the "Gray Goo Scenario," which posits that self-replicating nanobots, without built-in shut-offs or limitations, could produce exponentially, turning organic matter into a countless legion of nanobots. Thankfully, this is unlikely with these DNA nanobots as they cannot reproduce themselves or anything else without having sufficient supplies of precise DNA fragments and UV light.

You can read the study for yourself in the journal Science Robotics.