Well, the more I looked into this possibility, the more I think it's not going to look like traditional electronics that we know. Chances are, somebody's working on this right now, and we just don't know about it.

There's been some promising blips here and there with the reprappers:

http://blog.reprap.org/2011/06/new-approach-to-printing-meta...

http://blog.reprap.org/2012/04/some-more-printed-circuitry.h...