No, no, I was talking about hydraulic fluid, not a lubricant. The thingy you put into the ducts in order to apply a force and make mechanic parts move.
I mean, in muscles, you increase the influx of blood to contract the muscle and create an effort. In machines, you increase the pressure of fluid (as I said, in my language, we use something called oil), and it has the same effect.
The elf blood is supposed to transfer energy from the protein paste to the rest of the body, which apparently is very organic, since they are sometimes called cyborgs, and they take the pigment from the blood for their skin colour.
My point is simply that if you have to use fluid to move nutrients or create an effort, blood shouldn't be the go-to solution.
Economically speaking, I don't see how it works either.
You replace elves with bots that need elves as a source of 'fuel' (well, the protein paste is the real source of fuel, the blood is just the way to transmit energy to the body), but you still need to feed and take care of the elves. So yes, the bot doesn't need to sleep and doesn't need amenities.
But it needs patented food, and regular maintenance nonetheless.
None of the machines in any of the factories I worked in needed to eat or take vacations, but they needed maintenance and downtime.
Anyway, I perfectly understand it's sci-fi in a fantasy universe, so I'll gladly play the suspension of disbelief card.
