Nerves are very important. What is even more important is that they join up. Because when that message can't make it from point A to the brain (and back again), not much is going to happen. More important still, is that they join up the way they're supposed to.
Growing and reattaching nerve cells has been done, but getting them to grow in an orderly way, in the direction you want them to, is very tricky business. In a mammalian body, the nerve cells that regenerate do so along sheaths of myelin, which serve to both take neurons in the right direction and to speed up the transmission of neural information. As you may imagine, replicating such a three-dimensional microenvironment is difficult.
But now, a multidisciplinary team from the University of Wisconsin has developed new technology that successfully addresses this issue. Instead of allowing the nerves to grow randomly on a flat surface, the team introduced arrays of semiconductor tubes, made from silicon and germanium nanomembranes, that are electrically and physically similar to myelin.
What happens is as fascinating as it is predictable: the neurons sent their tendril-like dendrites along the tubes, even if the tubes spiral. And then, by making the tubes narrower than the cell body, the researchers are able to ensure that the neurons don't block the tubes and interfere with the dendrites' explorations.
Now the problem of directing cell growth has been solved, it should one day be possible to develop the kind of technology that would allow a tiny computer to 'communicate' with these neurons, as they reconnect previously severed nerves.
To get a better sense of the possibilities, here's some similar research from Georgia Tech: