What is a human being? I’m not asking on a philosophical level, but on a practical one. The answer is, of course, that we are multi-cellular organisms. We are a collective colony made up of individual living creatures called cells. Each cell is alive on its own, but all have grown to depend on each other by specializing, for the ultimate survival of the whole.
When we start out in the womb, we start out as a single cell – a combination of sperm and egg. That cell divides, the daughter cells divide, and eventually you have a complex human being. Some daughter cells become liver cells and others become part of the brain, but they all came from the same, single cell.
What is a cell? When you get right down to it, a cell is a machine – a complex, self-replicating, carbon-based machine. The definition of life has always been fuzzy at best, but at the level of a single cell it’s hard to miss the mechanical aspects of it.
This is not to degrade the cell, which is a marvelous and profoundly impressive thing. Instead, the idea is to demonstrate the power of microscopic, programmed machines to do great things.
If a cell is a micro robot created by nature through evolution, why can’t we too make microscopic machines that we program and control? That’s the idea behind nanobots, which have been hailed as an incredibly important invention for humanity’s future.
A Small Challenge
Making working machines this small is a tall order. For the most part it’s not something we have actually achieved yet but, of course, nature has shown us that it is possible thanks to the existence of cells themselves. There have been a few significant successes toward the goal of creating proper nanorobots, but the field of nanotechnology as a whole is already pretty well established.
If we’re talking about nanotechnology in general, this includes anything created or manipulated at the nanoscale, not just tiny robots. That’s why some products are starting to use it as a bit of a buzzword. You may now go out and buy laundry soap that has “nanoparticles” in it. Well, they had them before too, it’s just that no one cared what size they were.
While nanomaterials such as carbon nanotubes are amazing in their own right, if nanobots become reality they could bring about incredible implications for everything from medicine to construction.
How to Build A Nanorobot
“Nanobot”, or “nanite”, is a pretty wide term. It’s not as if we know yet what successful nanobots will look like or how they’ll be made. Still, there are many practical theories on how you could do it. For something to qualify as a nanobot it only has to be two things. First, it has to be sized at the nanoscale. Second, it has to be programmable. If something can fulfill both those criteria, you essentially have a nanobot.
A common vision of the nanobot is that it’s just like a big robot, but shrunk down – a little machine with a propulsion system and some way to manipulate matter at a molecular level. There are many potential designs for these sort of synthetic nanobots, a few of which are already crudely prototyped.
There are also many ways these could be made. For example, a nanoscale 3D printer is one option. Using lasers could also be complementary to 3D printing. In theory, you only have to make a few nanobots this way. Once you have a small number of working nanobots, you can set them to the task of making more of themselves. That’s both the beauty and the potential danger of nanorobots.
Why reinvent the wheel? Nature has already created nanobots in the form of bacteria and viruses. So why not just reprogram them to do a particular job? That’s exactly what genetic engineers are already doing today. The biggest downside is that these may be less controllable and less predictable, but since we’re still trying to make our own synthetic nanobots, obviously this method is the best short-term one.
There are two ways to go about this. One way is to take an existing bacterium or virus and rewrite its genetic code, to do a job that you want at the molecular level. This is not just a theoretical idea – it’s already happening. In 2015, for example, the FDA approved a treatment, for testing purposes, that uses re-engineered viruses.
Scientists are taking herpes viruses and genetically engineering them to fight cancer. Viruses are already on the fuzzy line that divides life from non-life – tiny robots just waiting to be reprogrammed. It doesn’t stop there, either. We’ve also actually managed to construct entirely synthetic life using modern gene-editing techniques.
Pioneering the field of artificial life is Craig Venter.
Venter is the big kahuna at Synthetic Genomics, which does just what you’d expect from the name – they make artificial genomes. While Venter has done many notable things, he’s best-known for being the first one to create truly artificial life. Craig created a bacterium with DNA he made on a computer. It is the only truly alien living thing on Earth, as it is in no way related to any other living thing we know.
This astounding proof of concept shows us that we can make our own microscopic life and program it genetically to do all sorts of jobs. Regardless of how we make our nanobots, the range of things we could use them for will change the world.
Master of the Elements
Imagine a world full of super materials for buildings so strong no natural disaster can touch them; cars and planes that are lighter and stronger than anything currently in existence. How will this happen? Well, when you build your materials one molecule at a time, you can make materials with incredible properties. Think about human bone – ounce per ounce it is stronger than steel. A lot of this strength is due to the fine structure of bone, which has an internal honeycomb-like weave that makes it both flexible and strong.
Another thing that bone can do is heal itself; using nanobots, our machines could also do this by repairing damage in the same way our cells do. In fact, since nanobots will likely have more precise communication with one another, the repairs could be much more precise and the equivalent of “scarring” could be avoided.
How to Grow a City
One of the most amazing potential uses of nanobots is in the construction of things. In principle, it should be possible to have a small number of nanobots “seed” a building; then, using raw resources from the environment or as provided, they would build large structures automatically. Imagine trillions of tiny robots all working together to make a skyscraper, and then working to perpetually keep it in optimal shape. Nanobots would be the equivalent of breathing life into our technologies and further blurring the line between our machines and natural machines such as plants and animals.
As you may expect, there’s no reason why the powerful potential of nanobots should be restricted to use on Earth. They represent one of the key future technologies needed to make other planets, such as Mars, habitable for humans. Of course, bio-engineered algae, bacteria, and other plants will also play an important role, but nanobots could use the abundant mineral resources on the Red Planet to kickstart colonization. We won’t even have to be there for it. Sending a probe with a payload of self-replicating nanobots to the surface of another planet would be a very hands-off project.
The initial colony of robots would land and then begin self-replicating, using materials from the planet’s surface. Once they achieve sufficient mass, the actual job of constructing the buildings and machinery can begin. We would only send actual people once the facilities were ready. This represents a far cheaper method of getting a foothold on worlds beyond Earth than any other technique. Right now we would have to lift tons and tons of equipment into space or complete the construction in low-Earth orbit. Sufficiently advanced nanobots could make these projects suddenly feasible.
A Strong Body and a Strong Mind
One of the most anticipated applications of nanobots is in the medical field. Medical nanites have the potential to end human disease as we know it. Even better, nanites theoretically could perform constant repair, radically increasing lifespan. Nanites may also be key to a number of other desirable medical outcomes – things like limb regeneration, the reversal of aging, and brain digitization for mind-uploading.
Nanobots could also play a role in human augmentation and help us interface with computer systems directly. For example, we have non-robotic nanites called respirocytes that increase the oxygen storage capacity of a human body. If you’re injected with a dose of respirocytes, you can hold your breath for a very long time.
The Gray Goo Problem
As amazing as the potential of nanobots is, there are some real danger inherent in the technology. In fact, it may be the most dangerous and destructive technology we humans ever create.
It’s called the “gray goo” problem, and it’s pretty scary. To explain it as simply as possible, gray goo is the equivalent of nanobot cancer. Cancer is what happens when your cells become damaged and can no longer self-correct or self-destruct. They begin to reproduce at full tilt, consuming everything around them in order to do so and destroying the body itself in the process.
So imagine a situation where some of your nanobots get corrupted in the same way and start stripping everything around them into material to make more corrupted nanites. It would become a cancer of the universe itself, eating inanimate matter until there is nothing left but a gray goo of corrupted nanobots. That’s a truly apocalyptic scenario and one we desperately need to avoid.
It’s also inevitable that nanites will be weaponized in various ways, so they would have the potential to become a new type of weapon of mass destruction.
Balancing it Out
Nanotechnology promises too much to ignore it completely. It seems inevitable that it will live up to its potential one day, so the best we can do is plan and prepare carefully for a future that will contain nanorobots. It may very well turn out that the biggest discovery in human history is also the smallest.