The human-shape bias has been brought up before
, and the consensus seemed to be:
* human-shaped heads and brains are easy to recognize as such
* when possible, use a brain without a head around it, which might seem a bit less human-centric
* it's not really that important to be species-neutral anyway
* it's hard enough to come up with icon ideas as it is, so we should avoid adding extra restrictions
There are more posts on the topic in that thread, if you're inclined to read more, but I think the above summary is accurate... though I didn't actually re-read it all to make sure.
For Psicorp, you might take inspiration from Babylon 5, and put the greek letter Psi ( Ψ ) in the image.
For fusion plants, perhaps a building-like shape with a lightning-bolt electricity shape between two spires, and in the middle a mushroom cloud, or something similar to the fusion generation tech.
For mining engineering, start with the standard pickaxe, and then maybe some geared wheels / cogs
behind it? It's a tough one, since there's isn't a cadeceus-like well-recognized symbol for engineering...