17 year old Easton LaChappelle has created his own robotic prosthetic limb out of an Arduino and a 3d printer. His first version, created back in 2010, was made from LEGO, a few servos and some fishing line, and was a simple robotic hand. He won 3rd prize for the teen category at the Colorado Science Fair, where he met a little girl who was born without an arm. After learning that a prosthetic limb costs $80,000, he set about building his own for a fraction of the cost.
This 3rd-generation arm is fully articulated arm that resembles the movement of a human's arm. Powered by an Arduino chip, the rest of the arm has been printed by a 3D printer. The arm can connect to a brainwave reading headset, where the user can then have accurate control.
It was revealed at TEDxMileHigh, where audiences were astounded, and he has since been offered an internship with NASA.