In this Friday, Dec. 6, 2013 photo, Nick McGill, center, wears the Titan Arm, as he poses alongside his student colleagues Elizabeth Beattie, left, and Nick Parrotta at the University of Pennsylvania in Philadelphia. The robotic device invented by the University of Pennsylvania engineering students, along with a fourth student, Niko Vladimiro, can help its wearer carry an additional 40 pounds. (AP Photo/Jacqueline Larma)
In this Friday, Dec. 6, 2013 photo, a view of the Titan Arm is seen at the University of Pennsylvania in Philadelphia. The prize-winning prototype builds on existing research in the field of exoskeletons, an area that experts say will grow as the population ages. (AP Photo/Jacqueline Larma)
In this Friday, Dec. 6, 2013 photo, Nick McGill wears the Titan Arm as he poses at the University of Pennsylvania in Philadelphia. Students say some current exoskeleton models can cost $100,000. They created the award-winning Titan Arm for less than $2,000. (AP Photo/Jacqueline Larma)