My campaign's party is situated on an habitable oceanic world (specifically Droplet), but away from civilisation. They have a Nautiloid variant, with the usual internal nanofabricator and an unusual inclusion of an antimatter-powered reactor (so energy is plentiful, for now). They also currently have a few synths suited for deep aquatic operation.
Their goal is to establish either a small outpost or a mobile base with self-sufficiency in terms of both energy and fabrication, since at some point they need to give away the reactor and the fabricator.
The planet gives very easy access to an abundance of CHON, and to a lesser extent to a few other like Si, Na or Cl, but other elements require either setting up high-throughput filtration systems, or finding and mining sources of abundance.
Given the above situation, it seems like CHON will be the main feedstock for any large-scale fabrication during the near future. On one hand, even just the carbon tubes alone are likely to be a very versatile material. On the other, it's been mentioned in the lore that at times fabrication is limited due to lack of less common elements, e.g. perhaps some things cannot be made without use of metals in construction.
Heart of the Question
I would like to know what things are likely to be impossible to fabricate out of CHON alone, and what elements or sorts of elements are likely to be necessary for those things.
Items of particular interest to me are:
- Electronics (including cyberbrains, sensors and comms, servers etc.);
- Room-temperature superconductors (of special interest for rechargeable batteries);
- 'Nuclear batteries'/RTGs (in addition to the the radioisotopes themselves, that is, which of course need to be prospected and mined);
- Deuterium fusion power plants (as per Rimward page 196);
- Heavy water separators (to feed those plants);
- Healing vats, ego bridges and other 'biomanipulative' gear;
- Equipment for producing, storing and using entangled particle pairs;
- Equipment for producing and storing stabilised metallic hydrogen;
- Equipment for storing (not producing) antimatter, and possibly even AM reactors themselves;
- Finally, full-fledged fabricators / cornucopia machines.