I'm an advanced AI in far futuristic sci-fi setting. To give you the size of how advanced we are, I'll just drop here a short list of our accomplishments:

  • We have discovered cold fission-reactors and mastered all the other known forms of energy
  • We have high tech robotics, both on large scale (enormous builder-bots) and microscopic scale (multi-purpose nanotech)
  • We can synthesize every kind of material, fabric, alloy, organic and inorganic compounds of your knowledge, plus some new and improved materials of our invention.
  • Our world is mainly governed by a few major AIs.
  • To be precise, the artificial intelligence is no more a "singularity": we can replicate it to whatever extent we like. AIs can be created to mimick completely the human brain, if needed, or the brains of other biological creature.

You got the point, I think, but feel free to ask for other details. Now, in our world both robotic and biologic life coexist to various extents. Of course, our definition of "life" is a little from yours, since we consider robots and AIs such as me to be alive.

Regardless, I've been furthering my studies on a little pet-project of mine: alas, creating a synthetic human lifeform capable of growth. Creating a robot that looks like a human is already a solved problem: it's just a matter of coating an exoskeleton with our improved skin-like silicon. We've become pretty good to mimic other bodily function too, like temperature, breathing and so on. Of course, as I've told you before, we can give that artificial body a totally human-like intelligence also.

What I want now is to design a synthetic body capable of mimicking growth. For convenience, this body should start around the apparent age of a human of three or four years old, and then be capable of growing into the apparent age of adulthood.

The body should be composed mainly of inert materials, like metal or plastic; I could add a certain number of biologically-engineered cells to the mix, but I'd rather avoid mixing biology with robotics more than necessary.

My safest bet is to load the body with nanobots, that I will program to gather the necessary compounds to "slowly expand" the body until the desired size. I worry if this option is viable, though, since the nanobots should exit the body once in a while to gather the necessary materials.

My aim here is to make possible humans unaware of the process.

Awaiting your precious input.

  • $\begingroup$ Let's make it clear - your synthetic human is not build from biological cells or their equivalents - most of the body are inert materials like metals and plastics? $\endgroup$
    – Alexander
    Oct 18 '18 at 20:26
  • $\begingroup$ @Alexander Exactly so. I suppose I could add a certain number of biologically-engineered cells to the mix, but I'd rather not, since biology seems a messy way of solving problems to me. $\endgroup$ Oct 18 '18 at 20:28
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    $\begingroup$ Your nano bots link together like ants do sometimes.. to make parts of the body . Or to deconstruct and reconstruct solid parts akin to bones.. probably during downtime like sleep. $\endgroup$
    – Richard
    Oct 18 '18 at 22:57
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    $\begingroup$ Biological cells are chemical factories - if you mastered true NANOtech, the replication of such a device on a microscale is (literally) a thousand times easier. As it would be a designed, rather than an evolved design, you could make it much more efficient than the human blueprint. There is enough silicon in sand (which a three-year old consumes in copious amounts...) to build to your iron hearts content - why would the nanobots ever have to venture out? $\endgroup$
    – bukwyrm
    Oct 26 '18 at 14:03
  • $\begingroup$ "We have discovered cold fission-reactors" - Do you mean cold fusion reactors? $\endgroup$
    – Vikki
    May 27 '19 at 2:51

If you want to make humans unaware the growing bot is anything other then human and avoid the nanobots having to leave to scavange material the easy solution I think is to have it eat. It sounds like the technology is there for the energy to run and the process to synthesize the materials you would need internally. Kids are well know picky eaters with food preferences that change with time. So maybe it only wants to "eat" red meat when it needs additional iron, then when it needs more Y compound it switches to wanting X food. 3-4 is old enough to use the toilet on your own so any unused material can be disposed of safely and discreetly, and if it looks different then a humans no one would be the wiser. I guess the question becomes can the needed breaking down and combining of materials take place in the space available based of the technology available. From a mass in to growth standpoint it should work though, as humans are able to do it and in theory a robot using the food to grow itself would be more efficient as it would not need to use that food for growth and energy. Assuming a seperate internal power source, which seems plausible based on your tech levels.


I would assume if you're that advanced it would be much easier to simply create a swarm of nanobots and have the swarm replicate a human body. If you need the body to grow you could ensure the nanobots can either create more of themselves or try to sneak in a fresh batch that would enable them to slowy grow the body.

The basics to being capable of growing is being able to produce the cells or matter in general to keep growing. If you can create a bloodlike fluid or use nanobots that can grow a plastic body then congratulations you can grow a plastic body.

  • $\begingroup$ So, the synthetic human in this case is essentially a "Nanomorph", like T-1000 android. $\endgroup$
    – Alexander
    Oct 18 '18 at 21:57
  • $\begingroup$ @Alexander Yeah, essentially it is. $\endgroup$ Oct 19 '18 at 17:18

A human cell is nothing more than a chemical factory that manages to reproduce itself over and over again. The cells have specializations to allow the body to survive and reproduce on a large scale.

With access to nanotech and any material in the world you can create 'new' biology and living matter using different materials than we are build out of now. Plastics and metals for a synthetic body? Thats wasteful. You build them from strings of Graphene Alloys so its very resistant against damage. Create chemical sequences thay provide power and building materials and have these take place inside the cells, which you build out of one of the trillions of compounds you now have access to, many of which would be buildable from what we eat everyday, and the synthetic could seclude himself on the playground for example to attempt to find materials otherwise not present in human food.

With your tech level, the distinction between biology and machine is long gone. Humans are likely just as synthetic as the synthetic is going to be using biological parts.


1) give it human blood!

without human blood, the first blood analysis may bust your robot!

enter image description here source

2) give it human skin!

Most of the times we get in touch with our enviroment with our skin, it has many quite unique characteristics, for example, it can get damaged by sharp things, illnesses, chemicals, uv, heat, and so on in various ways, improved skin-like silicon alone could never mimic those things, without the aid of highly advanced nanobots. Why should one fake a sunburn with so much effort if one can get a real one?

enter image description here


4) fill it with fake organs and meat (wich roughly look like the real versions, but may be completeley different regarding microscopic structures), wich house the nanobots!

...just in case your robot has an accident and gets operated.

enter image description here source

5) house all the actual main components (power sources, al, motors, network) except artificial nerves used for sensing (wich must be really thin so one wont find them during operations) in the skull and the skeleton!

no one will ever have to fix the skeleton, since you can make it so strong that it doesn't break and real human skeleton usually don't let x-rays pass, so you can hide everything inside without having to worry about how it looks on x-ray.

enter image description here


6) take care that your robot, when burned down, leaves the same stuff a human body would leave too!

When humans are burned, only 5% of the mass of the human remain as ashes, including teeth. your robot has to become such ashes too, when burned.

...just think of what happens when the robot dies early, and the humans decide to cremate it and get some strange electric junk as remainder... (it would be too suspicious if the 0-year old robot said "plz dont cremate me after i die,ok?")

enter image description here source

7) let your robot assimilate and dispose stuff like humans do (as suggested by Crouse), but watch out that the deposited stuff looks like humans organic waste!

...just think of your robot going onto some blocked up toilet (without knowing that), disposing strange waste, and leaving the toilet for the plumber to come and fix it. what should it do? take the waste out again? that would seem just as strange as the waste would seem to the plumber...

enter image description here



Complete the genome project

First you need to know what makes a human and what is individual characteristics of the individual.

Design your pet

Using the known genome, just design what you want your human to be like. Hair color, personality traits, diseases he's more likely to have and all of the little details your heart desires.

Program your language

Program a language that can read the genome as a input and reacts to it just like the enzymes and chemistry of a human body would. In essence, the human body is a protein synthetizer and by the level of technology you have, that seems to be fairly possible. Just input the dna you want to express and it'll run itself.

Manufacture nano cells

Nano cells would be a group of nano robots that in conjunction would form an cell analog. Have that cell be the hardware and apply the language you created as an OS. The nanorobots should be able to synthetize anything just as you describe on the OP.

Apply the code for the human

Apply the code you have as dna(TACG) to the cell. Make changes as desired for the material outcome. If you want to make silicon instead of keratin for the skin, just change the output of those keratin codes(TACG) to a silicon synthesis. Change any analog you want from organic to inorganic.

Let it run freely

If the code is correct and the language translates it properly, just press the play buttom and let it run.

Digestory tract

As an addition, you'll need to design a better digestory system. One that allows for inorganic materials to be digested and used in the body. As in other system, some microlevel adaptations will be needed.


By definition, it can grow. It can grow like a human too, with enough programming/planning.


(1) The gradual increase (e.g. in size or number) of an animal or vegetable body over time.

(2) The development of an organism, e.g. of a plant from a seed to full maturity.

Growth has two key aspects to its definition. You may want to narrow your question down to which part you are interested in. However in both cases I can see no reason why growing a synthetic human would not be possible. With enough technology that is.

Edit: Based on your comment.

All growth is, is following a script to make certain parts bigger (1), and change certain parts to do more things (2, maturation). That is the big picture. What chemicals are involved and what processes are used is irrelevant, and will in fact change depending on the organism/species. So really what is growth? It is changing an "organism's" anatomy to have new function, or to have more of something.

Now let us assume you have the futuristic scenario that you have described. I assume we have nanobots. I assume we can program said nanobots to follow some kind of plan. With this plan they can make predictable changes to an object. In this case the object is robot. Evolution and mutations are clearly not a key part of growth, and are thus excluded in this scenario (though I am sure you can program that in too with enough work).

So if you can program said nanobots to increase the size of a robot, and its superficial functions so that it looks, talks, and acts like a human... then by definition has it not experience growth? Yes it has. Taking this to its logical extreme, you could also do this to a rock, or any object. I would go so far as to say that something doesn't even have to be alive, for it to grow. However biological growth is mostly concerned with '(2)', maturation. This can still be applied to an inanimate object, but depending on your interpretation you may; want the growth to originate from within the object; follow a predictable and reproducible path; etc. Again all these aspects are easily achieved by nanobots with the right script. If you want to go deeper and start pondering on whether synthetic life is really life, you can start discussing whether the nanobots can be considered 'cells'.

I think the question of whether these synthetic humans are actually alive is so profound and interesting that it should not be hand waved. It is also not convincing to hand wave that they are 'life' when they are missing very obvious key concepts of life, like the ability to reproduce. In fact, you should look at the key aspects of life.

As long as you have someone smart enough to program the nanobots however then growth should be possible, no-problem.

So the answer to this question is a resounding yes.

If you find this concept unacceptable then I suspect that you are asking the wrong question. Obviously real life is defined by many more things than just growth. So maybe what you really want to ask is, "What does a synthetic human made of plastic and steel have to have, in order to be considered a unit-of-life in biological terms". The answer to this question is very different to whether or not a robot can mimic one aspect of life.

  • $\begingroup$ I'm sorry, but I don't find your answer useful. The first part tries to deconstruct the premises of my question (yea, I know that rocks can grow, but this is not the point). Also, it doesn't matter if your life definition doesn't match my in-world one, since they are supposed to be different. The last two sentences are relevant to the question, so maybe you can expand on that? $\endgroup$ Oct 25 '18 at 20:17
  • $\begingroup$ I have changed the answer. Hopefully it is clearer. $\endgroup$ Oct 26 '18 at 14:14
  • $\begingroup$ I retracted my downvote and upvoted, since now after the edit the answer is on point, since now it addresses the "mimicking human growth" part. To further clarify, I too wanted to employ nanobots massively, but wasn't 100% sure about it - hence the question. You're right that I shouldn't handwave the definition of life: i will not in my setting and there's probably space for another question. $\endgroup$ Oct 26 '18 at 14:17
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    $\begingroup$ @Liquid, Thanks for your input. If you have any other aspect you are interested in, then let me know and maybe I can give you an answer in the comments. $\endgroup$ Oct 26 '18 at 14:18

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