I am interested in building replacements for every single body part and bodily function, (with a sort of non biological replacement, more electrical and mechanical.) in order to support the brain. I know that the brain is the least understood body part, but my wonder is just how understood is it? If actuators controlled by brain signals were to be made, how far from knowing which areas of the spinal cord that could control such actuators, (be they artifical muscle or actual motors!) are we? I ask because if we are so far from such a thing that it would be impractical for me to study appropriate fields enough to reach such a goal, then I would choose another goal, such as physics or engineering power systems, which I like slightly more. If it is not impractical, or even already achieved, (I have searched online but have not found anywhere that says such progress) then I would find it MUCH more worth my time studying biomedical engineering, and whichever appropriate fields required to achieve the goal I mentioned above. Preserving the brain itself is another story, I believe it will require nanotechnology, but I know the least about that. Any comments on that would be great. Thanks, Jonny PS: If I have not worded the above well enough, then I will explain it simpler: Is it achievable in my lifetime (I am 18) to build a completely non-biological replacement body to support the brain, and perhaps even other systems to prevent the brain itself from degrading?