If you’re a fan of science fiction, you’ve probably heard the term “nanorobots,” “nanobots” or even “nanites.” Most likely, you have some rough idea of what they do and how they work. They’ve been used to wipe out diseases from the bloodstream, perform delicate repairs on equipment, augment human abilities, and other things. They’re practically invisible, smart, and able to perform tasks like nothing else.
One of the reasons they’re used so extensively in sci-fi these days is that we have known about the potentials of nanotechnology for some time now. The promises in the medical field are profound; we could be looking at a technology that would bring an end cancer and viruses like HIV once and for all. But even though we already have nanotechnology now to a certain extent, we don’t yet have nanites in production. But if we did, what would they be made of?
Carbon nanotubes: Ah, nanotubes. One of my professors in college was an expert in the field. Carbon nanotubes could be the single most important technological development of our time. Carbon is the most important element in life as we know it, and one important property it has is that it always forms four bonds. Because of this, we can make entire sheets of carbon atoms (the result being known as graphene), and from those sheets, we can roll them up into nanotubes. These tubes can be insulating, conducting or semi-conducting based on the geometry of your roll. They can be used for very small structures that are both strong and versatile. But they have applications in the macro world too: they are used in conjunction with fabrics to reinforce them, and they are even used in conjunction with carbon fiber to bolster its strength. A theoretical use in the space industry would be to build the core of a space elevator, since each atom is bound to its neighbors and can resist buckling and shearing forces. Unfortunately, a flaw has been discovered in it: a structure that tall would have to be perfect, without a single carbon atom out of place. It’s sort of like a chain: no stronger than its weakest link.
A wide variety of robotic parts could be constructed from nanotubes. Gears, arms, hinges–nearly everything. Another recent development is the creation of nanotube transistors that run twice as fast as the traditional silicon transistors. They also do so with much less power. Every computing device you’ve ever owned has probably used transistor technology to run; processors are essentially collections of very tiny transistors. With nanotubes, these transistors can be made even smaller, and far more can fit on a chip. And with nanotubes, we’re looking at tiny programmable processors that act as “brains” for nanorobotic “bodies.”
DNA: DNA nanotechnology may seem odd, but follow along here. The helical structure of DNA makes it perfect for building hinges, and therefore moving parts. It’s tough, rigid, and can be activated chemically. They are also great for building molecular “tweezers” for precision gripping and manipulation.
Bacteria and viruses: Okay, this probably seems odder. Bacteria can be used in combination with electronics for propulsion purposes. Engineered viruses can be used to insert new DNA into a cell, replacing other, faulty genes.
It’s unlikely that every nanorobot will be constructed the same way, or even with all the same materials, as there will be different robots for different tasks. Some will be made to seek out and destroy. Others will be made to perform repairs on cells, bones and organs, and yet others will be used to cure diseases down to the genetic level. The next logical step in the development of nanorobotics is the ability to build new tissue, down at the cellular level. Such a system would not only cure diseases, but also constantly keep the body in a state of repair to fight the aging process. They could also work in conjunction with larger machines like 3D printers.
Another possible application is to create a permanent technological environment for artificial implants. Imagine being able to buy some kind of chip from an Apple store that you can stick in your arm–who knows what the chip could do?–but nanorobotics could automatically incorporate the chip into your nervous system. How about electronic synthetic muscles? That’s a tall order–better get the nanobots to handle the intricacies. Want to enhance your brain power? The nanobots would deliver artificial circuitry to give you more processing power.
There are fears that are inherent to this sort of thing–and they may not be unfounded. For example, what if the nanobots disobeyed instructions? If they can operate in unison as well as individually, what’s to say they won’t perform tasks other than those programmed into them? That’s unlikely. The implication behind the fear is that nanorobots, due to their versatility, could form an artificial intelligence, one that could potentially develop its own rules on how to help their masters. But the processing power of each individual nanobot would be highly limited (if it had any at all). It’s doubtful that nanorobots would ever need to interface with each other for information transfer, by design; besides, so much variability in individual designs means the different molecular machines inside of us would be like Babylon: everyone’s speaking a different language. We’re talking highly specialized devices that do one, maybe two things. In other words, if we wanted our nanorobots to rebel against us, we’d have to tell them to.
The possibility of manufacturing self-replicating nanorobots leads to another fear, this one maybe not so unfounded: the threat of “gray goo.” If nanorobots are programmed to automatically recreate themselves from available materials, there’s the potential that they will make all materials in the environment available, consuming everything to make “offspring.” The more of them there are running loose, the more there are to convert raw materials into more nanorobots. On paper, this is entirely possible. They are so tiny–how could you stop them? But breaking down matter and reassembling it takes energy. And from energy, you get heat. Heat is detectable, and a heat signature will lead the cops right to your doorstep. Such a catastrophe would be easily contained, brought to an end before it becomes a runaway process.
So, there’s a lot that can be done with nanorobotics in medicine. We can wipe out diseases altogether. Mend bones quickly. Make our organs work more efficiently. Maybe nanotechnology can prevent death altogether. Imagine the other possible applications too: using nanorobots to put nutrients back into soil for growing crops. Or to manipulate the soil on other planets to make it fertile for Earth-native foods. Hell, maybe nanorobots will one day build the spaceships themselves, and keep them working. And is it possible that they could also become the building blocks for larger, macroscopic machines?
I would say the sky’s the limit, but in this case–it’s not!