Neurobiological Mechanical Engineering (It's a Thing!)

      So I've been thinking... for the sake of prosthesis would it perhaps be possible to invent a new type of wire that would be compatible with human nerves, thus allowing it to be wired into a human nervous system? This, I understand, sounds absolutely insane but with some research I found that nerves and wires have quite a lot in common (granted, they also have plenty of differences but the point is that there ARE commonalities).
     Here is a diagram of a human nerve cell:

   And here is a diagram of your standard copper wire: 

     As I said there are many differences, obviously, but electricity is electricity. The big difference is that the conductor used in copper wire, copper, is formed by a metallic bond of copper atoms which are nice and conductive because it is metal. Nerves, on the other hand, use polarized ions to conduct electrical currents with a high concentration of negatively charged chlorine ions on the inside and positively charged sodium ions on the outside that, when stimulated, switch places using the righteous power of diffusion. However, both neurons and copper wire are conductive, electrically sensitive materials nestled inside an insulator (polyethylene for wire, myelin for neurons), both serve the purpose of electrical conduction, and they are shaped somewhat similarly. I know, at this point this sounds like I'm just a rambling drunk but I swear I am completely lucid! This thought just sprang into my mind a couple days ago so I've been thinking about it.