Two years ago, Paul McCarthy began searching for an inexpensive yet functional prosthetic hand for his son Leon, who was born without fingers on one of his hands. McCarthy came across a video online with detailed instruction on how to use a 3-D printer to make a prosthetic hand for his son. Technology is fascinating.
Here’s the instructions for the 3-D printer prosthetic hand: http://www.thingiverse.com/thing:44150
Also check out this recent TED Talk by Henry Evans on how robots allowed him to live again.