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.

Synthetic Nanobots

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.

Biological Bots

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.