So my biomachine person, who will go by bob for the question, his very unique. He has machinery replacing half his organs and skeleton. Bioengineered cells work alongside and support the mechanical parts of his body. He has an anti matter reactor in his chest which burns super slowly to produce electricity for all of the machinery in his body for centuries. His cells have been engineered to function off of raw electricity instead of converting oxygen and food (a type of bacteria do this so cells can theoretically do it too right?). Since solid wires would be impractical due to the constant shifting and dynamic nature of cells, he uses a special fluid to delivery electricity to all of the cells and machinery.

The question is what that fluid is. I know water is a conductor (apparently diluted water isn’t but with some salt it is) but I didn’t know if there was a much better/cooler option. I think a superconductor fluid would be pretty cool but most superconductors need to be very cold to work and so being in a liquid state seems hard and also the anti matter reactor would definitely warm it up above room temperature. So this “blood” needs too:

  • Work at room temperature, preferably on the much warmer side
  • Be an efficient means of transporting charge
  • Would be nice but not necessary if it was easy to produce with organic elements (so bob doesn’t need to eat some weird ore to keep his blood pressure up)
  • Would be nice but not necessary if it could double as a coolant since it is hooked up directly to the main internal heat producers and to the rest of the body to radiate said heat

So far salt water seems like the answer because I’m pretty sure it matches all of those boxes but it seems so lame alongside antimatter reactors, quantum computers, and bioengineered cells. But if there is much cooler, and maybe more efficient, alternatives please do tell!

  • $\begingroup$ What do you mean with "diluted water"? $\endgroup$
    – L.Dutch
    Commented Jan 16, 2022 at 6:25
  • 1
    $\begingroup$ @L.Dutch - I suspect they mean "distilled" water, which is a terrible conductor. I would also point out that blood is saline, so it's already a pretty good conductor. That said, if Bob's cells are magically (and it would be magical, because there's a giant leap between bacteria and multicellular organisms metabolising electricity) able to sustain themselves on electricity, they'll still need water to maintain hydrostasis, so a blood variant seems reasonable. (He also doesn't need to breathe, so it might be a different colour.) $\endgroup$
    – jdunlop
    Commented Jan 16, 2022 at 6:40
  • $\begingroup$ The trouble is that the circulatory system is a loop. If replace the heart with an electricity-generating reactor, your blood vessels will still be a loop, and you'll get a short from one side of the reactor to the other, leading to the blood replacer boiling... which probably isn't what you want. The circulatory system isn't designed to do what you need it to do. $\endgroup$
    – Monty Wild
    Commented Jan 16, 2022 at 8:33
  • $\begingroup$ Why use liquid for this? You are better off using nerves or your biomachine alternative to feed all the cells electricity, and the regular blood circulatory system to provide the nutrients and stuff to keep up growth and repairs of the body and machine. $\endgroup$
    – Demigan
    Commented Jan 16, 2022 at 18:20

3 Answers 3


Unfortunately, this isn't going to work at all.

The trouble is that the circulatory system is a materials transport system, and this question is trying to convert it into a conductor for electricity.

If we were to replace the blood in the circulatory system with a superconducting fluid, and replace the heart with an antimatter to electricity generator, producing its charge output across its former blood inputs and outputs, we would have what electricians call a dead short, since the circulatory system is connected from arteries to arterioles to capillaries to veinules to veins and back to the heart.

Were we to build such a circuit without a circuit breaker in the heart/generator, we would immediately get a massive current flowing around the circulatory system, so high that the superconductivity of the fluid would break down. The antimatter reactor would continue to output thousands upon thousands of amps of current through the now merely conductive circulatory system fluid, heating it until it boiled.

The visible effect of this on this would-be superhuman within a second of the antimatter reactor being switched on would be a substantial explosion, splattering fragments of cooked human meat all over the walls and likely blowing out any windows.

Alternatively, the heart/antimatter generator might simply fail from being over-driven.

In either of these situations, if the antimatter reactor didn't fail safely, it might lose containment of its antimatter... and then a substantial portion of a city - or a country - might then disappear in a fireball to put a mere atomic weapon to shame.

Of course, if the reactor did have a circuit breaker, it would merely trip immediately. Depending upon how fast it tripped, the subject might even survive the experience.

Unfortunately, the circulatory system cannot easily be repurposed into an electrical conductor. It is designed to go past cells, carrying oxygen and nutrients in, and carrying metabolic wastes away. It does not go to each cell, stop, and then continue at the other side of the cells, and making it function that way would require that the subject's body be effectively rebuilt from the ground up.

Now, if the circulatory system was carrying tiny atomic batteries, which were physically transported from the heart, to the circulatory system and from there to each cell, we might be onto something...

  • $\begingroup$ Superconductivity won't cause shortcuts per se. The electric current is actually used up by the creature's organs which are part of the circuit, there won't be a short circuit. The arteries are perfect conductors, but when the current goes through the organs and muscles, there will be a internal resistance and dissipation of heat, mechanical movement, or whatever the electricity is used for. Compare it with an electronic circuit with superconducting wires. The electricity is consumed by the components, not by the wires. $\endgroup$
    – Goodies
    Commented Jan 16, 2022 at 12:35
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    $\begingroup$ @Goodies Not so. The circulatory system is a continuous loop that branches out in the organs and comes back together at the heart. If it's all filled with a conductor from the arterial side, it'll fill up right to the venous side. Apply a current at one side of the heart and it'll go all the way around to the other side. It's like having a battery, a motor and some wire, where you connect a wire to the battery, then to one terminal of the motor, then to the other terminal, then to the other side of the battery. Because there's a connection between the motor terminals, it's shorted. $\endgroup$
    – Monty Wild
    Commented Jan 16, 2022 at 12:45
  • $\begingroup$ Sure, there could be lots of components in parallel.. and the artery system needs a redesign. An electric circuit is always a loop, connecting a power supply to the components that sit in that loop. Superconductivity reduces losses in the wires. But the components these wires are connected to draw power and add up to the internal resistance of the loop. This resistance will reduce the current and prevent shortcut. When you want to move a muscle, that will cost energy and in this case, that energy translates into resistance. So there will be no shortcut, when the energy is used. $\endgroup$
    – Goodies
    Commented Jan 16, 2022 at 12:52
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    $\begingroup$ @Goodies, if you use superconducting fluid in the circulatory system and run electricity through it, the electricity will follow the path of least resistance and bypass all the organs. If you have a battery, two wires and a motor, the motor runs until you drop a wire across the motor terminals and short it out of the circuit. That is what you have here. $\endgroup$
    – Monty Wild
    Commented Jan 16, 2022 at 13:46
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    $\begingroup$ In addition to Monty Wilds valid comments - if you re-designed the circulatory system so the superconducting fluid no longer short-circuited via the capilliaries, then the fluid would no longer circulat, so it certainly couldnt have the dual role of being a coolant. $\endgroup$
    – Penguino
    Commented Jan 16, 2022 at 20:55

Frame Challenge

Yes, there's a lot of bending back and forth, which could break wires, but wouldn't the same apply to your bioengineered blood vessels?

If you want to keep this closer to a biological model, look inside your typical multicellular animal for cells that already can send electrical signals.

In an animal, the nerves send data. Why not let your CPU connect use bioengineered nerves provide data connections to cells, but also plug in your power source so each cell gets its power from the same connection? Think of the nerves as bioengineered USB cables.

This still leaves you with a cooling issue, but that's primarily around your power supply.

  • $\begingroup$ Not all cells are connected to the nervous system. Some parts of the body are relatively far from any nerves. $\endgroup$
    – Monty Wild
    Commented Jan 16, 2022 at 9:53
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    $\begingroup$ @MontyWild, good point, but since these cells don't need sugar and oxygen, but do need power, why not connect a dendrite from a nerve and get power and data collection? Imagine the usefulness of being able to call up statistics on the status of cells by type and location. $\endgroup$ Commented Jan 16, 2022 at 10:37
  • $\begingroup$ What are you going to use as a return current path? Lymph? That's just asking for a short circuit too. You need effectively insulated cables, not poorly insulated axons. $\endgroup$
    – Monty Wild
    Commented Jan 16, 2022 at 10:43
  • $\begingroup$ @MontyWild - Although the idea is based on nerves, it's not going to be an exact copy of a real nerve any more than the other bioengineered cells are going to be exact copies of the cells they will have similar functions to. I'd assume bioengineered nerves capable of privoviding power and data would have dendrites equivalent to a USB connection capable of providing both directions of current flow via a reasonable number of connections to each cell. The power levels needed to power something the size of a cell shouldn't need massive insulation. $\endgroup$ Commented Jan 16, 2022 at 11:21
  • $\begingroup$ So... not a single poorly-insulated cable, but a few thinner insulated cables in the place of the axons. It isn't impossible, but you'd want gold conductors, and you'd end up rewiring the whole body, which is kinda what the OP would need to do to repurpose the circulatory system. $\endgroup$
    – Monty Wild
    Commented Jan 16, 2022 at 14:26

Conductive polymers and organic superconductors already exist, so keep the blood for relaying materials and waste products to and from the cells and organs, and repurpose some (but not all) of the nervous system to act as an electrical grid by replacing the myelin sheaths with flexible superconducting organic polymer fibres.

As an added McGuffin, Bob can have superconducting coils in his fingetrtips that can produce strong localized magnetic fields when desired - there must be a use for that!


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