New Micrometer-Scale Robot Manufacturing Technique Could Revolutionize Medicine

Medical nanobots have long been a hallmark of science fiction for good reason: they would be incredibly useful. These tiny robots could, theoretically at least, swim through our blood vessels to reach targeted organs and deliver medications or perform repairs. While it seems likely that we will have these kinds of nanobots eventually, we aren’t exactly close. Manufacturing at the nanometer scale is a massive challenge and the physical nature of moving a robot that size is also a problem. But, thanks to the work of researchers from ETH Zurich, we may be able to construct micrometer-scale medical robots out of metal and plastic in the foreseeable future.

A micrometer, also called a micron, is one-millionth of a meter. For reference, that is about a tenth of the length of a red blood cell. That is, however, still far larger than a nanometer, which is one-billionth of a meter. Nanobots are generally defined as robots that are constructed from nanometer-scale components. This new technology, which could be used to fabricate robots as small as a micrometer in length, isn’t capable of producing nanobots by most definitions, but it is close. Robots produced using this manufacturing technology don’t look like much more than simple frames, but they are composed of two different materials: iron and polymer. With the precise application of external magnetic fields, the iron “wheels” can be rotated to facilitate locomotion through the body.

This is all possible thanks to a manufacturing process developed by the researchers, which starts with a very precise 3D printing method called 3D lithography. They used this to 3D-print tiny molds that are somewhat analogous to the tooling used for injection molding. Instead of simply pumping these with molten material, which wouldn’t work at this scale, electrochemical deposition is used to fill grooves in the mold with the desired material. By selectively applying materials with varying properties, machines can be created that are actuated by the external magnetic fields. The physical structures of the robots can be modified for different purposes, such as drug delivery and even simple surgical procedures. We likely won’t see robots like this being used in real world applications anytime soon, but this manufacturing technique is a significant step towards the nanobots we’ve seen in science fiction.