'Bionic Man' to Climb Skyscraper He'll walk up all 103 flights to show off the new prosthetic leg By Liam Carnahan, Newser Staff Posted Oct 31, 2012 12:15 PM CDT 8 comments Comments In this Oct. 25, 2012 photo, Zac Vawter, fitted with an experimental "bionic" leg, is silhouetted on the Ledge at the Willis Tower in Chicago. Vawter is training for the world's tallest stair-climbing... (AP Photo/Brian Kersey) (Newser) – This Sunday, when Zac Vawter thinks "climb the stairs," he'll take the first step in what could be a very big development for prosthetic science. Vawter lost his right leg in a motorcycle accident in 2009, and has since been fitted with a prototype of the first bionic leg, which is controlled by his thoughts. He's set to demonstrate the device by climbing all 103 flights of Chicago's Willis Tower, reports the AP. The leg works by using electrical impulses in the muscles of his hamstring to move the bionic leg. During his ascent, Vawter will be joined by 2,700 other climbers as part of a fundraiser for the institute that developed the technology. If his climb is a success, it "suggests in the next 10 years or so there will be good commercial devices out there" for others who have lost lower limbs, says a researcher.