Zac Vawter on the Willis Tower’s SkyDeck.

We can rebuild him. We have the technology. Especially since that technology is an $8 million bionic leg.

Zac Vawter lost his right leg in a motorcycle accident, and Sunday he got to take the leg for a spin. He climbed the 103 floors of the Willis Tower for the Rehabilitation Institute of Chicago’s annual fundraiser “SkyRise Chicago.”

The amazing thing about bionic technology is how it syncs up to your nervous system. Vawter didn’t have to push any buttons to make his leg move – all he had to do was think about it. Sensors in the leg were connected to the muscles in his hamstring. When he thought about moving his leg, the sensors picked up on electrical impulses in the muscle and operated two motors in the prosthetic leg.

Vawter will have to leave the leg behind when he goes back to his hometown of Yelm, Washington. Researchers in the project, which include scientists from Vanderbilt University, the Massachusetts Institute of Technology, the University of Rhode Island and the University of New Brunswick, want to further improve the leg.

Along with the leg, Zawter himself did a darn good job. He climbed the 2,100 steps in 53 minutes and 9 seconds.