the 3d printing part is only aesthetical, people have been taking their lifes by just using a bag or whatever else can contain the nitrogen from a tank
Air: A Sabatier reactor uses CO2 and Hydrogen to make methane and water, then the methane can be heated in an oxygen-less atmosphere (pyrolysis) to get hydrogen and elemental carbon, and you can electrolyze the water to get oxygen and hydrogen. the hydrogen from the methane pyrolysis and water electrolysis is enough to use again in the Sabatier reactor, while the oxygen can then be used again to breathe.
For the food: A bit harder, for a closed loop like for the air you would need to chemically recycle pee and poo which IS possible, just insanely complicated (and gross, and dangerous).
A better method for food, if you had access to water, would be to turn water into steam, then use the elemental carbon from the Sabatier reactor and the steam to make syngas.
Once you have syngas, make Methanol with it, and then convert the methanol to Formaldehyde with a catalyst.
Once formaldehyde is obtained, use the Formose Reaction to make various sugars.
Then, use the sugars to eat or to feed animals/plants.
Idk about other stuff tho, all the proteins, vitamins etc
it could probably be possible to make them with genetically modified yeast/bacteria that feed on the sugar, but AFAIK this doesn't exist yet (the above part of air+water to sugar is possible with current technology, tho)
How people are so confident in sharing their DNA, something you cannot change, that you will carry on for your entire life, and that can uniquely identify you with just a small sample, to a private, profit-driven company still amazes me
And the worst part is, even if you're careful about it, all that's needed is a relative doing it and now the company can basically tell most of your family tree
And all for what, knowing the parents of the parents of your parents come from some neighboring country? No shit, Sherlock, people move around
it is, but you need to have some chemistry knowledge to be able to extract it from things like anal lube, and that's where I think this DIY project will shine
Copying the text from another comment i made here:
I have a standalone bidet, not the toilet bowl attachment, which is basically a mini sink, and it works like a sink in that you can regulate flowrate and temperature with the handle
with this kind, you have 100% cleanliness since you use your hand to clean everything, and after it there's a mini-towel for each person, usually in a towel rack near the bidet so no-one gets confused, and usually in a smaller size then normal towels.
If you're worried about the idea of using your hand being unhygienic, rest assured, there's a radical invention called washing your hands afterwards, which, by the way, you should do anyways even if you use toilet paper.
the 3d printing part is only aesthetical, people have been taking their lifes by just using a bag or whatever else can contain the nitrogen from a tank