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Bionic Stair Climber

Zac Vawter arrives on the 103rd floor of Willis Tower, becoming the first person ever to complete the task wearing a mind-controlled prosthetic limb, Sunday, Nov. 4, 2012 in Chicago. Vawter, who lost his right leg in a motorcycle accident, put the smart limb on public display for the first time during an annual stair-climbing charity event called “SkyRise Chicago” hosted by the Rehabilitation Institute of Chicago, where he is receiving treatment. (AP Photo/Teresa Crawford)