Hugh Pickens writes writes "AP reports that Zac Vawter, who lost his right leg in a motorcycle accident, put his mind-controlled prosthetic limb on public display for the first time climbing 103 stories up the 2,100 step staircase of Chicago's iconic Willis Tower, becoming the first person ever to complete the task wearing a bionic leg during an annual stair-climbing charity event called "SkyRise Chicago" hosted by the Rehabilitation Institute of Chicago. "Everything went great," said Vawter at the event's end. "The prosthetic leg did its part, and I did my part." The robotic leg is designed to respond to electrical impulses from muscles in his hamstring. When Vawter thought about climbing the stairs, the motors, belts and chains in his leg synchronized the movements of its ankle and knee. Researchers spent months adjusting the technical aspects of the leg to ensure that it would respond to his thoughts and continue to refine steering of the leg. "We've come a long way, but we have a long way to go," says lead researcher Levi Hargrove adding that taking the leg to the market is still years away. "We need to make rock solid devices, more than a research prototype.""