Tim Hemmes, of Butler, Penn., has been paralyzed from the neck down for eight years following a motorcycle accident. He is able to speak normally and looks like a regular, if thin, 31-year-old, sitting about a foot taller than the scientist around him because of his mobile chair. His arms have been resting at the sides of that chair for eight years. Then on October 2011, he thought about reaching out to his girlfriend… and a robotic arm next to him extended and did it…