| Date | 7th, Dec 2020 |
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When you hear about robots, you typically imagine some giant machines traversing difficult terrain on Mars or some industrial equipment making cars. However, some of the most useful robots are quite small. In fact, very small – scientists at the ETH Zurich have developed a technique for making micrometre-long machines, which could one day revolutionise the field of medicine.
Tiny robots like this can be used to deliver drugs to a precise site in the body. (Photograph: Alcântara et al. Nature Communications 2020)
Imagine a robot, which can navigate the inside of your body. It could go from one part of your body to the next one, travelling exclusively through blood vessels. How useful would that be? It could deliver medicine specifically to one location that needs treatment and not contaminate the entire body. The effectiveness of the drugs would be greater, side effects – smaller. And now scientists have a good idea how to manufacture such robots, because they developed a nanorobot manufacturing method, based on interlocking multiple materials in a complex way.
Scientists used a 3D printing method, known as 3D lithography, to create a mold. It can then be filled with chosen materials using electrochemical deposition. Some of the grooves in those molds are filled with metal and some – with polymers. Finally, the template can be dissolved away, leaving a tightly joined cluster of metal and polymers, which can then serve as a tiny robot. Scientists created several different miniscule vehicles with plastic chassis and magnetic metal wheels to demonstrate the effectiveness of their method. Of course, a robot like this would be powered by external means – alternating magnetic fields would guide the robot. Depending on the chosen materials, these robots can float in liquid or roll on glass.
Nanorobots would be extremely useful in medicine, but they have to be unbelievably small. We are talking micrometres. This means that most manufacturing methods are just incompatible with a scale this small. Furthermore, because metal is needed for magnetic control and polymers are needed to make robots soft and flexible, these medical nanorobots are usually made from hardly compatible materials. Carlos Alcântara, one of the authors of the study, said: “Metals and polymers have different properties, and both materials offer certain advantages in building micromachines. Our goal was to benefit from all these properties simultaneously by combining the two”.
The future is robotic – we’ve known that for a long time. But maybe we imagined our robots a little too big – these tiny medical nanorobots have absolutely no brain or electronics and yet could be the most useful medical tool of the 21st century.
Source: ETH Zurich
