He will put this groundbreaking "bionic" leg to the ultimate test Sunday when he attempts to climb 103 flights of stairs to the top of Chicago's Willis Tower, one of the world's tallest skyscrapers.
If all goes well, he'll make history with the bionic leg's public debut. His whirring, robotic leg will respond to electrical impulses from muscles in his hamstring. Vawter will think, "Climb stairs," and the motors, belts and chains in his leg will synchronize the movements of its ankle and knee. Vawter hopes to make it to the top in an hour, longer than it would've taken before his amputation, less time than it would take with his normal prosthetic leg -- or, as he calls it, his "dumb" leg.
A team of researchers will be cheering him on and noting the smart leg's performance. When Vawter goes home to Yelm, Wash., where he lives with his wife and two children, the experimental leg will stay behind in Chicago. Researchers will continue to refine its steering. Taking it to the market is still years away.
"Somewhere down the road, it will benefit me and I hope it will benefit a lot of other people as well," Vawter said about the research at the Rehabilitation Institute of Chicago.